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c06_1 10/08/2007 365

Cider Apples and Cider-Making

Techniques in Europe and North
America
Ian A. Merwin
Department of Horticulture, Cornell University,
Ithaca, NY, 14853 USA

Sarah Valois
Cherrypharm Inc., 500 Technology Drive,
Geneva, NY, 14456 USA

Olga I. Padilla-Zakour
Department of Food Science Technology
NYSAES, Geneva, NY, 14456 USA

I. INTRODUCTION
A. Origins of Cider and Perry
B. Cider Production and Characteristics
1. Apple Categories
2. Apple Tannins
3. Apple and Cider Flavor Profiles
4. Cider Milling and Pressing
C. Fermentation Techniques
1. Yeast Nutrients
2. Temperature Effects on Cider Fermentation
3. Ciders versus Wines
4. Polyphenolic Amendments in Cider
D. Bottling and Handling Ciders
E. Chemical Characteristics of Ciders
1. Cider Acidity
2. Cider Sugars
3. Cider Tannins
4. Aromatic Flavor Components
5. Cider Appearance

Horticultural Reviews, Volume 34, Edited by Jules Janick

ISBN 9780470171530 ß 2008 John Wiley & Sons, Inc.

365
c06_1 10/08/2007 366

366 I. A. MERWIN, S. VALOIS, AND O. I. PADILLA-ZAKOUR

II. ORCHARD SYSTEMS FOR CIDER APPLES

A. Modern versus Traditional Cider and Perry Orchards
B. Cultivar Characteristics
C. Orchard Nutrition and Cider Quality
III. NATIONAL AND REGIONAL CIDER CULTURES AND
CULTIVARS
A. France
B. Spain
C. The United Kingdom
D. North America
IV. LITERATURE CITED

I. INTRODUCTION

In western Europe and North America, there is an old tradition of apple

(Malus
domestica Borkh.) production for fermented or ‘‘hard’’ ciders.
The word cider and its equivalents in European languages usually
imply the fermented form of juice from apples and will be used in that
sense herein. The scope of this review includes the history and current
situation of cider apples and fermented cider production in Europe and
North America, including the different types of apples that are grown
specifically for cider, various styles of cider-making, and current
research activities and priorities in cider production. The related tradi-
tion of pear (Pyrus communis L.) production for perries (fermented pear
juice) will also be considered briefly in contrast to cider apples. Our
approach will be broad—involving horticulture, food and fermentation
science, regional histories and cultures, the genomic and chemical
attributes of cider apples, and some key differences between dessert
and cider apple production. Because there are extensive research pub-
lications in each of these areas, our review will of necessity be selective.
For more comprehensive reviews specifically on fermented cider, read-
ers can refer to Beech (1972), Downing (1989), Lea (1995), and Lea and
Drilleau (2003).

A. Origins of Cider and Perry

The origins of cider can be traced only partway back through the
domestication and development of cultivated apples (French 1982;
Juniper and Mabberly 2006). By 1000 BCE, apples, pears, and various
processed derivatives of these fruits were part of the diet in the Medi-
terranean region. The biblical era Hebrews consumed a fermented drink
derived from apples known as shekar; and in classical Greece apples
were boiled and fermented to make sikera (Mitchell 2006). The first
historical mention of perry dates to the fourth century CE, when it was
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6. CIDER APPLES AND CIDER-MAKING TECHNIQUES 367

referred to as piracium by Saint Gerome. As with wine grapes, the

Roman conquest and colonization of Europe led to dissemination of
improved cultivars of apple and pear. However, the Roman invaders
of England in 55 BCE reported that indigenous peoples there were
already consuming fermented ciders made from local apples (French
1982).
The earliest named European cider cultivars were distinct from the
indigenous M. sylvestris crabapples that grew wild in the forests of
western Europe, resembling more the hybridized M.
domestica types
of that era (Boré and Fleckinger 1997; Browning 1998). The region and
era in which the modern cultivated apple originated is not known
precisely, but DNA fingerprinting studies using various methods and
markers suggest that interspecific hybridization among M. sieversii and
M. sylvestris (or M. pumila) occurred several thousand years ago, result-
ing in the domesticated cultivars grown today for both dessert and cider
usage (Zhou and Li 2000; Harris et al. 2002; Juniper and Mabberley
2006). Hierarchical cluster analyses of genomic markers indicate that
traditional European cultivars used for cider should be grouped with
M.
domestica and that M. sieversii is their dominant ancestor. How-
ever, the cider cultivars differ substantially from dessert cultivars at the
phenotypic and the genomic levels, suggesting that they resulted from
geographically and anthropogenically distinct selection processes
(Hokanson et al. 1998; Goulao et al. 2001).
In the millennia before humans developed water treatment and san-
itation practices, the safest way to quench one’s thirst was often a drink
of fermented cider, beer, or diluted wine. These natural beverages were
easy to make, low in alcohol, relatively free of pathogenic microbes, and
readily available (Vallee 1998). In northwestern Europe and colonial
New England in the United States, cider was produced and consumed
in rural areas wherever the climate was too cold for vinifera grapes to
survive or beer-making technology was as yet undeveloped. To this day,
antique apple grinding stones are a common sight in northern France
and southwest England—an enduring legacy of the cider tradition in
these regions. For an entertaining historical perspective on the knowl-
edge and methods of the late 1600s for producing apples and ciders, an
annotated facsimile edition of The Compleat Planter & Cyderist, written
in 1685 by an anonymous British ‘‘Lover of Planting,’’ was recently
published (Juniper and Juniper 2003).
Traditional New England farms usually included apple orchards, and
most were within a half day’s wagon ride from a local cider mill, where
the apple crop was pressed and then brought back in barrels to be stored
in the farmhouse cellar for consumption during the next year (Watson
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368 I. A. MERWIN, S. VALOIS, AND O. I. PADILLA-ZAKOUR

1999). The unfermented sweet cider that remains a popular drink in

North America was available only briefly during harvest time before the
development of refrigeration and preservatives, and even today fresh
unfermented cider is rarely consumed in Europe.
In the pre-industrial era, palatable ciders could be produced with
minimal technological understanding or intervention, because indi-
genous yeast microflora (Saccharomyces cerevisiae, S. bayanus,
Metschnikowia pulcherrima, Kloekera apiculata, and related species)
that occur naturally on apples will spontaneously ferment the sugars in
fresh-pressed juice put into barrels. However, the quality and consis-
tency of ciders fermented from naturally occurring yeasts and other
fermentative microflora present on apples are unpredictable, because
S. cerevisiae is usually not the dominant species in uninoculated ciders
or wines, especially at the outset of fermentation (Beech and Davenport
1970). After a few months at ambient cellar temperatures, a relatively
pathogen-free product around 5 to 6% ethanol by volume usually
results, with ethanol concentrations determined primarily by the yeast
strains and initial sugar concentrations in the juice. Barrels in which
oxygen enters to ‘‘spoil’’ the cider are usually converted naturally to
cider vinegar by indigenous lactic acid bacteria (Lactobacillus, Leuco-
nostoc, Pediococcus sp.), and the resultant vinegar was a historically
important preservative that could be used for pickling and other culi-
nary purposes.
Because of its versatility and availability, cider was very popular in
New England during the 1700s—with annual per capita consumption in
Massachusetts estimated more than one barrel (about 200 liters [l]),
suggesting that adults may have consumed several liters each day
(Watson 1999). As noted by Pollan (2002), during the ‘‘Johnny
Appleseed’’ era of open-pollinated seedling orchards on subsistence
farms in North America, most of the apples were likely to have been
small, bitter, and sour. Considering also that they were grown without
effective controls for disease and insect pests, these apples were prob-
ably more useful for cider than for fresh fruit consumption.
People commonly drank cider with each meal in colonial America,
and it was even used as payment and refreshment for field workers. It
was served during mealtimes in the cafeterias of Harvard University
during the mid to late 1700s (Orton 1973), and cider played a role in
American politics. George Washington and John Adams were apple
growers and avid cider drinkers. Cider was also referenced in one of
the first populist campaign slogans, ‘‘Tippecanoe and Tyler Too,’’
where it was paired with a log cabin as symbols of the typical American
home (Proulx and Nichols 1980).
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6. CIDER APPLES AND CIDER-MAKING TECHNIQUES 369

As urban populations and industrialization increased in Europe and

North America during the 1800s, beer making became relatively more
practical than cider making to meet urban consumer demand. Barley
(Hordeum vulgare) grain was easier than apples to obtain in bulk and
transport into urban areas, so beer became more economical than cider
for large-scale urban production. The temperance movement of the late
1800s in America further discouraged cider consumption in favor of
abstinence or presumably less alcoholic beers, and eventually cider
consumption was reduced to a few relict areas in Europe and North
America (Morgan and Richards 1993). Since the 1970s, consumption of
cider has experienced a resurgence in both Europe and North America.
Global off-trade sales of cider and perry were estimated at 873 million l
in 2005, valued at U.S. $2.9 billion, and have been increasing (GMID
2006; Mitchell 2006). The United Kingdom, South Africa, France,
Ireland, Germany, and Spain currently are the top six countries in
cider/perry consumption (Table 6.1). Production and consumption
of perry are limited almost exclusively to the United Kingdom and
France, and account for less than 1% of the global total. There is
also a substantial amount of cider consumed on-trade (meaning in
pubs as opposed to off-trade in stores and shops) in France, Spain,
and the United Kingdom. An unknown amount of cider is made for
home consumption throughout Europe and North America and for
distillation into apple ‘‘brandies’’ in eastern Europe. Therefore, the
total sales volume and value estimates for cider in Table 6.1 are con-
servative, and the real market value is probably more than U.S. $3
billion.

Table 6.1. Cider production/consumption and trends by country and region. Total
estimated sales value worldwide in 2005 were more than US$ 3 billion.

Country or Region Total (million L) Five-Year Trend

World total 1065 Increasing

United Kingdom 510 Increasing
South Africa 170 Increasing
France 125 Decreasing
Ireland 80 Increasing
Germany 75 Level
Spain 70 Increasing
All others 35 Increasing

Source: Data from GMID database 2006; Mitchell 2006; and www.info-cidre.com.
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370 I. A. MERWIN, S. VALOIS, AND O. I. PADILLA-ZAKOUR

B. Cider Production and Characteristics

Cider is made by fermenting apples either as milled fruit or pressed
juice. Although there are a few apple cultivars that are sometimes
fermented into good quality single-cultivar ciders, such as ‘Kingston
Black’ and ‘Northern Spy’, most ciders are blended from different
cultivars to achieve a desired balance of acidity, sugar, and tannins.
All apples can be classified into three broad categories based on their
utilization: fresh/dessert, processing/culinary, and juice/cider. Fresh/
dessert apples usually have high soluble solids content (primarily
sugars and sugar alcohols; e.g., sorbitol), low to moderate titratable
acidity, low polyphenolic content, and distinctive aromas or flavors
(Valois et al. 2006). Processing/culinary apples often have textural
properties important for peeling, slicing, or saucing and lower sugar:-
acid ratios than dessert apples, resulting in a tarter taste. Juice/cider
apples can be either culls from the other two categories or special
cultivars grown exclusively for fermented cider usage.

1. Apple Categories. Some of the apples traditionally grown for ciders

have high concentrations of polyphenolic compounds, rendering them
unpalatable for fresh consumption, but imparting to ciders a desirable
complexity, body, and a well-rounded mouth-feel (Lee and Drilleau
2003). These apples are not generally consumed as fresh fruit, because
their high levels of polyphenolics or tannins make the fruit taste astrin-
gent (commonly described as ‘‘soft tannins’’) or bitter (‘‘hard tannins’’).
The cider apple category can also include cultivars that are grown
primarily for dessert or cooking usage, due to the broad range of sugar
and acidity characteristics within the cider/juice category.
To help cider-makers obtain the optimal blends and ratios of acidity,
polyphenolics, and sugar-derived alcohol or residual sweetness in their
products, a quantitative apple classification system was developed at
the Long Ashton cider research station in the United Kingdom during
the early 1900s. Every apple can be classified within one of four cate-
gories based on these criteria:

1. Sweet (<0.2% polyphenolics weight per volume of solution (w/v),

and
<0.45% malic acid w/v)
2. Bittersweet (>0.2% polyphenolics w/v, and <0.45% malic acid w/v)
3. Sharp (<0.2% polyphenolics w/v, and >0.45% malic acid w/v)
4. Bittersharp (>0.2% polyphenolics w/v, and >0.45% malic acid w/v)
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6. CIDER APPLES AND CIDER-MAKING TECHNIQUES 371

In France and Spain, an intermediate category, ‘‘acidulée’’ or ‘‘acid-

ulada,’’ (respectively) is sometimes used for semitart cider cultivars
with low tannin content (Boré and Fleckinger 1997).
Most dessert and culinary apples fall within the Sweet or Sharp
categories, while most of the special cider cultivars are Bittersweets,
with relatively few classified as Bittersharps. Because the Bittersharp
cultivars contain sufficient tannin content and produce ciders with
adequately low pH (<3.8), they can be fermented as a single-cultivar
juice to produce so-called vintage ciders, such as ‘Kingston Black’ and
‘Foxwhelp’ (Barker 1947; Copas 2001). However, apart from a few
cider-makers in England and the United States who promote single-
cultivar ciders, most cider-makers prefer to use blends because that
practice usually produces the best and most consistent quality. A
high-quality cider blend will usually contain enough Bittersweets
and Bittersharps to ensure clarity, balance, and a pleasant astringency;
enough Sharps to keep the cider pH below 3.8, suppressing the growth
of spoilage organisms during fermentation and storage or aging,
including Zymomonas anaerobia, which is responsible for ‘‘cider
sickness’’; and enough Sweets to provide adequate sugar for fermen-
tation to the desired final ethanol content, usually 3 to 7% (volume/
volume). In practice, cider-makers in Europe typically utilize a mix-
ture of apples containing at least 20% Bittersweets or Bittersharps to
obtain the optimal sugar, alcohol, acidity, and tannin ratios in their
finished ciders. Depending on each country’s regulations, the remain-
ing 80% of the juice may consist of Sharps, such as ‘Brown’. Apple’ in
England or ‘Calville Blanc’ in France—added to provide enough acid-
ity—and bulk juice from fresh-market apple culls or juice concentrate
in England (Mitchell 2006). A good blend of apples for making fer-
mented ciders therefore includes tart, aromatic, neutral/base, and
tannic cultivars.
There is no systematic classification of North American apple culti-
vars for cider-making purposes, and most fresh or fermented ciders in
the United States are made from culled dessert apples, generally con-
sisting of Sweets and Sharps, with relatively low polyphenolic content.
Examples of apples commonly available in North America and recom-
mended blend percentages for each category were described by Proulx
and Nichols (1980, 2003) and more recently by Merwin (2005), but there
are minimal data to support these recommendations, which are based
primarily on anecdotal or historical practices. This is an area where
more quantitative research is needed to support the developing cider
industry in North America.
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372 I. A. MERWIN, S. VALOIS, AND O. I. PADILLA-ZAKOUR

2. Apple Tannins. Most of the polyphenolic tannins in cider apples are

flavonoid epicatechin procyanidins, although chlorogenic and cou-
maroyl quinic phenolic acids and phloridzin are also present in many
cultivars (Lea 1990, 1995; Lea and Drilleau 2003). Apple phenolics are
complex polymeric molecules, with varying numbers of phenol sub-
units. The perceived flavor or ‘‘mouth-feel’’ of apple phenolic com-
pounds is more bitter and harsh when the predominant procyanidins
are oligomeric (2 to 4 phenolic subunits). These short-chain polyphe-
nolics are informally described as ‘‘hard’’ tannins, and cultivars with
characteristically hard tannins sometimes include the word bitter in
their names (e.g., ‘Tremlett’. Bitter’, ‘Ellis Bitter’), sometimes being
described as ‘‘spitters’’ because of the usual first reaction of those who
taste them. Copas (2001) mentions a tradition of planting these bitter
cultivars around the edges of orchards in the English countryside, to
discourage thievery by passersby.
As the number of phenolic subunits increases in apple tannin mole-
cules, their mouth-feel softens and becomes more astringent and less
bitter. These ‘‘soft’’ tannin cultivars may have the same or greater total
concentrations of procyanidins as the hard tannin types, but their
sensory perception in the mouth is quite different. Chemical analysis
of total polyphenolic concentrations is thus not definitive with respect
to the flavor attributes of cider apples (Lea and Arnold 1983), and high-
performance liquid chromatography (HPLC) or other analytic methods
are required to determine the specific types of polyphenolics present in
fruit or ciders (Suarez et al. 1996).
In the presence of oxygen, oligomeric procyanidins tend to link into
polymeric forms, and can also bind to fruit solids in milled pulp or cider
sediments. The perceived flavor and mouth-feel of cider can therefore
change over time, and depends on exposure to oxygen, the addition of
antioxidants such as metabisulfites, the mixture of hard or soft tannin
cultivars, the amount of ethanol in each cider, and extractions of poly-
phenolics such as quercitin from oak (Quercus robur L.) cooperage (Lea
and Arnold 1978; del Campo et al. 2003).
In European countries with major cider industries, Bittersweet and
Bittersharp apples are grown exclusively for cider production, and the
characteristic tannin content, total acidity, and fermentable sugar con-
tent have been determined for hundreds of apple cultivars (Williams
1987; Fuertes et al. 1996; Boré and Fleckinger 1997; Pereira-Lorenzo
2002). At present there are about 18,000 hectares (ha) of orchards grown
specifically for ciders in Europe. Presumably most of these trees are
Bittersweets, Sharps, or Bittersharps, because it is usually possible to
obtain less expensive bulk apple juice or juice concentrate to make up
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6. CIDER APPLES AND CIDER-MAKING TECHNIQUES 373

the remaining portion of cider blends and provides adequate sugar and
acidity (Jarvis 2001; Lea and Drilleau 2003; Desmarest 2004). A few
dozen of the traditional Bittersweet and Bittersharp cultivars from west-
ern Europe are now being planting in the United States and Canada,
mostly in small orchards by local cider-makers who need high-tannin
cultivars to make traditional European-style ciders.
It is difficult to ascertain exactly how many hectares of cider orchard
exist in North America, because statistics on cider plantings by culti-
var in the United States are not available through tree-census sources
such as the U.S. Department of Agriculture, which does not gather
information specifically for fermented cider cultivars. Other cultivars
or species that are grown for ornamental purposes or as pollenizers in
commercial orchards include crabapples such as M. mandshurica or
M. floribunda, which contain relatively high concentrations of phe-
nolic compounds and malic acid compared with dessert apples. These
crabapples can be added to blends for cider but are not used as the
main source of juice, because their elevated concentration of phenolic
compounds and malic acid may impart too much bitterness and acid-
ity to the cider.

3. Apple and Cider Flavor Profiles. Apart from the source apple
blends, other factors also contribute to the flavor profile of a cider,
including the methods of milling and pressing, the maturity and
condition of source fruit, and the addition of apple juice concentrate
or refined sugar (Le Quere et al. 2006). Various fermentation methods
and conditions can also influence the flavor of the cider, and there has
been extensive research on these techniques in England (Lea and
Drilleau 2003), France (Drilleau 1985; Le Quere et al. 2006), Switzer-
land (Durr 1986), and Spain (Mangas et al. 1994). Important factors in
cider flavor include the amount of added sulfites, yeast species or
strains, yeast-available nutrients, time and temperature of fermenta-
tion, titratable acidity and pH, malolactic fermentation, reduction of
spoilage microorganisms, and addition of other ingredients such as
preservatives, sweeteners, carbonation, or colorants in the final bot-
tling (Beech 1972; Proulx and Nichols 1980; Cabranes-Benduero 1991;
Jarvis et al.1995; Jarvis 2001; Lea and Drilleau 2003; Del Campo et al.
2003). Apart from a substantial number of recent studies involving
phytosanitary issues in fresh cider (to be discussed in more detail later),
little research has been conducted or published on cider flavor in North
America. Most of the published scientific reports from the United
States and Canada have involved cider juice or concentrate quality,
not fermented ciders (e.g., Downing 1989).
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374 I. A. MERWIN, S. VALOIS, AND O. I. PADILLA-ZAKOUR

4. Cider Milling and Pressing. Various types of mills and presses are
used to extract juice from cider apples, and these presses influence the
efficiency of extraction, the extent of tannin extraction from seeds and
skins, and the resultant cider quality (Lea and Drilleau 2003). The most
efficient presses are very large-scale industrial units such as the Bucher-
Guyer horizontal piston press, or continuous belt presses, that can
batch-press many tonnes of apples per hour, mechanically loading
and dumping, at extraction efficiencies around 80% (w/w) (Bump
1989). Addition of pectic enzymes and pressing aids such as wood
shavings or rice hulls can increase juice extraction efficiencies by about
5% and are especially useful with perry because it is more difficult to
press pears than apples. Many small-scale cider-makers use the
hydraulic or screw rack-and-frame press, where successive layers of
milled apples are folded into nylon press-cloths and stacked in a
‘‘cheese’’ of a dozen or so layers that is pressed slowly under increasing
pressures to obtain the juice. The rack-and-frame press is more labor-
intensive and less efficient than the continuous-belt type or Bucher-
Guyer presses, but it is also less expensive and hence is used by many
small-scale producers.
The traditional French and English cider milling and pressing
method involved a horizontal circular stone trench into which apples
were dumped while an ox or horse pulled the axle of a large vertical
stone wheel rolling around in the trench (Copas 2001). These mills were
not very efficient at juice extraction, and after the screw press was
invented in the 13th century CE, it gradually replaced the old stone
mills because it was more efficient and could be operated with smaller
batches using human power (Mitchell 2006). To this day, some Spanish
cider-makers still use a very large version of screw or lever press called
the lagar (Fig. 6.1). The lagar relies on lathed oak or metal screws, or
very long levers, to exert a relatively low pressure over many days on
apples milled into fairly large chunks, piled into a single mass that is
contained between stout oak staves in a cubic press measuring 2 or 3
meters (m) in each dimension (Arumburu 1991; Garcia 2004). The tradi-
tional lagar press is not efficient, but it produces a characteristic highly
colored, low-tannin cider with substantial volatile acidity that is pop-
ular in Spain.

C. Fermentation Techniques
Proper control of fermentation through chemical and nutrient additions,
temperature control, and microflora reduction or inoculation allows
for a ‘‘clean’’ and consistent fermentation that is unlikely to produce
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6. CIDER APPLES AND CIDER-MAKING TECHNIQUES 375

Fig. 6.1. A traditional Spanish oak lager screw press in operation. Pressing can take
several days, allowing partial mash fermentation, development of volatile acidity, and
binding of tannins on fruit solids, producing characteristic Spanish ciders. Source: Photo
reproduced from Garcia 2004.

off-flavor compounds or other defects. The main processing steps for

cider-making can be seen in Fig. 6.2. The first objective at the juice stage
is to reduce the numbers of wild yeast and bacteria in order to allow for
dominance by the pitched (added) Saccharomyces yeast. Inoculation
with cultured pure yeast strains ensures consistency in the flavor profile
and alcohol content of cider. There are multiple drawbacks to ‘‘wild’’
yeast fermentations—such as unpredictability and variability in cider
stability, flavor, and alcohol level. Nevertheless, some cider-makers
have attributed the characteristic ‘‘cider flavors’’ and increased produc-
tion of desirable ester odor compounds and added flavor complexity to
only non-Saccharomyces or other wild yeasts (Beech and Davenport
1970; Beech and Carr 1977; Lea and Drilleau 2003).

1. Yeast Nutrients. To help ensure that inoculated yeasts will increase

promptly and dominate during the subsequent fermentation, nutrients
are often added to the juice or must. Yeast needs sugar or a carbon source,
nitrogenous compounds, B vitamins, minerals, and yeast hulls (to help
remove any toxins in the juice or those produced by yeast activity). Yeast
can use nitrogen (N)–containing compounds in the form of all primary
c06_1 10/08/2007 376

376 I. A. MERWIN, S. VALOIS, AND O. I. PADILLA-ZAKOUR

Fig. 6.2. Flowchart of typical steps and procedures in modern cider-making. Source:
From Valois 2007.

amino acids except proline, and ammonia compounds. Nitrogen is

essential for yeast growth and is used in many pathways and reactions.
The amount of N in apples ranges from 10 to 300 mg N/l, which is much
lower than the 20 to 2,000 mg N/l usually occurring in grapes for wine-
making, suggesting that N supplementation of ciders may sometimes be
necessary if a rapid and complete fermentation is intended (Beech and
Carr 1977; Boulton et al. 1999; Lea and Drilleau 2003). The B vitamins are
also essential for yeast growth and must be added to the fermentation
because apple juice is low in them. Industrial cider-makers and wine-
makers generally add a complete yeast nutrient blend (supplement),
which contains the B vitamins as well as a nitrogen source such as
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6. CIDER APPLES AND CIDER-MAKING TECHNIQUES 377

diammonium phosphate (Lea and Drilleau 2003). Adding a sole N source

without the addition of a complete yeast nutrient package can result in a
harsher-tasting cider or one with more volatile (acetic acid) acidity (Cone
1997).
Ciders and wines made from low-N juice are more susceptible to
hydrogen sulfide production and sluggish or incomplete fermentations
(Agenback 1977; Kunkee 1991; Henick-Kling et al. 1996). The yeast-
assimilable-nitrogen (YAN) content in cider apples is usually less than
in wine grapes, and is also influenced by specific cultivars, soil con-
ditions, and climate conditions during the annual growing season
(Butzke 1998; Shively and Henick-Kling 2002; Cheng and Schupp
2004). Various N levels are reportedly necessary to support Saccharo-
myces during a complete fermentation, ranging from at least 150 milli-
grams (mg) N/l for fermentation to occur, with levels up to 328 to 473 mg
N/l for a complete fermentation and sulfide-free wine (Henschke and
Jiranek 1993; Monteiro and Bisson 1993; Jiranek et al. 1995). Typical
recommendations for industrial ciders are to supplement the juice up to
100 mg N/l (Lea and Drilleau 2003). To the contrary, some artisanal craft
cider-makers in France and England take measures to strip as much N as
possible from their ciders, in order to achieve ‘‘stuck’’ fermentations
that preserve residual sugars and limit the ethanol content in the fin-
ished cider. In any case, it is important to monitor juice N content and
not add too much, because excess N can lead to undesirable aromas and
microbial instabilities in the finished product (Butzke 1998; Bauduin
et al. 2006).

2. Temperature Effects on Cider Fermentation. Temperature is an

important variable in the cider fermentation process and is relatively
easy to control. Temperature affects most aspects of yeast metabolism,
including length of the cell-division stage and yeast tolerance to
alcohol (Jackson 2000). Cider fermentations can occur between 108
and 328C, with various rates and flavor profiles correlated to the differ-
ent temperatures and yeast strains involved (Fleet and Heard 1993;
Lea 1995). Typical fermentations are done between 158 to 258C, with
maximum yeast growth and metabolism occurring between 208 and
258C. Higher temperatures can produce negative sensory attributes and
may even stop the fermentation if too high (Fleet and Heard 1993; de la
Roza et al. 2002). A fermentation at 258C will go to completion quicker
than one at 158C (Jarvis et al. 1995), and slow fermentations achieved by
cool temperatures or N limitation often produce ciders with fruitier
aromas and flavors (Cone 1997; Lea and Drilleau 2003). Killian and
Ough (1979) reported increased production of esters with fruity aromas
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378 I. A. MERWIN, S. VALOIS, AND O. I. PADILLA-ZAKOUR

in wines fermented at lower temperatures, and Valois (2007) observed

similar effects in cider fermented with N supplementation at 128C
compared with 208C. Historically, cider-makers had little control over
fermentation temperatures, other than using late-ripening cider apples
so that temperatures in the cidery were likely to be cooler as winter
approached at harvest end. Various techniques to reduce the N content
of musts were thus developed, so that fermentation could be limited by
starting with juice of low N content, rather than cooler temperatures
(Lea 1995).

3. Ciders versus Wines. It is useful to compare techniques used in wine-

making with those for cider-making, because there are similarities but
also fundamental differences. One important difference relates to juice
and ethanol contact with fruit seeds and skins. Fermentation on the skins
or with entire berries is a common practice in red wine-making (Jackson
2000). This technique is used to extract color, phenolic compounds, and
other flavor components into the wine. Large portions of phenolic
compounds, particularly proanthocyanidins that add complexity and
longevity to wines, are found in grape seeds, skins, and stems as com-
pared to the berry flesh (Sun et al. 1999). However, prolonged skin
exposure and high temperatures during this primary fermentation period
can lead to off-flavors, high tannin levels that are coupled to astringency
and bitterness, excess production of methanol, volatile acidity, and
‘‘overextraction’’ in wines. In this context, cider fermentation is more
similar to production of white wines; there is usually little contact with
berry skins during the fermentation process, and optimal flavors are
usually obtained by careful selection of yeast strains and maintenance of
cool (128–208C) temperatures during cider fermentation.
As noted previously, achieving the right amount of phenolic com-
pounds is key to making a stable and well-balanced wine or cider.
Except in ciders intended for distilled eau de vies (water of life), mash
fermentation (which is analogous to extended red wine fermentation on
the skins) is not often used in cider-making, due to its interference with
tannin extraction in the cider. Unlike red wine-grapes, with cider
apples the desired effect of extracting more phenolic compounds
through contact with milled pulp is often not achieved, because the
phenolics bind with solids in the pulp and may be retained with the
solids when juice is pressed (Lea and Drilleau 2003). French cider-
makers often take advantage of this process with a technique known
as macération et cuvage that involves extended juice/pulp contact and
can be manipulated to determine to depth of color and astringency or
bitterness of the resultant ciders (Beech 1993). A traditional milling and
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6. CIDER APPLES AND CIDER-MAKING TECHNIQUES 379

pressing technique used in Spain—large-volume mechanical presses

(lagares) that may require almost a week of pressing to obtain the juice—
often results in incipient fermentation and tannin/pulp interactions
during the mash pressing stage, and is an important aspect of traditional
Spanish cider-making (Arumburu 1991).

4. Polyphenolic Amendments in Cider. The simplest and least expen-

sive way to increase the phenolic content of the cider is to add grape
tannins, because powdered apple tannins are not commercially avail-
able. Supplemented tannins add body and mouth-feel that ciders or
wines made from juice low in phenolics may lack. Powdered tannins are
available in multiple forms: gallotannins from gallnuts or galls that form
on oak (Quercus sp.) trees, ellagitannins from oak or chestnut (Castanea
sp.), and proanthocyanidins from processed grapes (Kahn and Anderson
2005). Gallo- and ellagitannins can be hydrolyzed to release gallic or
ellagic acid and are referred to as hydrolysable tannins; they are not
naturally found in grapes or apples. Proanthocyanidins, also called
condensed tannins, are found in grapes and apples. Valois (2007) eval-
uated different types of tannin addition in ciders and reported that
organoleptic panelists could distinguish readily and had clear prefer-
ences among the resultant flavor profiles. The general lack of availability
of high-tannin apples in North America has led many cider-makers there
to use grape tannins or to plant their own orchards of Bittersweet or
Bittersharp cultivars.

D. Bottling and Handling Ciders

After fermentation is complete, the cider must be racked, clarified, and
filtered to remove the lees, yeast, and other microorganisms before it is
bottled. Most industrial ciders are bottled with some added sweetness to
balance their acidity, and many are carbonated under external pressure
to provide effervescence (Mitchell 2006). Carbonation can be added by
external carbon dioxide under pressure, or through a secondary fermen-
tation in the bottle after addition of a small amount of sugar and yeast
(the dosage) during bottling of a ‘‘bottle-conditioned’’ champagne-style
product (Alonso-Salces et al. 2004). Consumer acceptance of bottle-
conditioned ciders in the United States has been problematic, in part
because yeast sediments in the bottle may cause visible turbidity that is
not acceptable to those unaccustomed to such ciders. External carbo-
nation can be added in the storage tank by injecting carbon dioxide
(CO2) or to each bottle immediately before capping. In order to have a
stable product for extended shelf life, cider with residual sugars must be
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380 I. A. MERWIN, S. VALOIS, AND O. I. PADILLA-ZAKOUR

heat-treated, or sulfur dioxide (SO2) and preservatives such as potas-

sium sorbate can added to prevent refermentation or spoilage microbial
growth in the bottle (Lea and Drilleau 2003). Chemical stabilizers such
as sulfites and preservatives can have negative sensory impacts on the
cider, especially when used at the high levels needed to stabilize a
product with added sugar (Jarvis et al. 1995).
An alternative to chemical stabilization is pasteurization, which can
be performed in batch form or after bottling, depending on available
equipment and the presence of carbonation. In-bottle pasteurization
allows for carbonation to be preserved, while direct pasteurization of
the unbottled product will reduce the carbonation, because the solubil-
ity of CO2 in aqueous solutions is inversely proportional to temperature
within the operational range of cider-making. Duration and temperature
thresholds determine the effectiveness of heat treatments. Pasteuriza-
tion units (PU) are used to define the necessary time-by-temperature
interactions in this process, based on the equation PU ¼ t
10(T-60C)/z,
where t is time in minutes, T is temperature in 8C, and z is 78C. Cider
needs approximately 50 PUs, heated for 50 minutes at 608C or an
equivalent time and temperature combination, for a stable product
and complete suppression of potential spoilage microorganisms (Duffy
and Shaffner 2001). The resultant cider will not be completely steri-
lized; thus it is necessary to have a low initial microbial load (Mitchell
2006). One disadvantage of in-bottle pasteurization is that it may cause
‘‘cooked’’ or oxidized flavors in ciders; close attention to temperature,
time, and free SO2 levels can minimize these negative effects.
A recently developed alternative to sulfites and pasteurization is the
use of a processing aid and cold sterilant—dimethyl dicarbonate
(DMDC, trade name Velcorin1)—which can prevent fermentation and
reduce spoilage microorganisms in juice and wine (Threfall and Morris
2002; Williams et al. 2005). This treatment is approved for juices and
wines at 250 parts per million (ppm) but not yet approved for cider due
to lack of demand from the cider industry. DMDC hydrolyzes immedi-
ately into minuscule amounts of methanol and carbon dioxide after
introduction into the product without affecting its taste, odor, or color
(Lanxess 2005). However, the equipment and procedures required to
use DMDC for cider stabilization may be prohibitively expensive for
small-scale cider-makers.

E. Chemical Characteristics of Ciders

Apart from water, the main components of cider are organic acids,
sugars, alcohols, and polyphenolic compounds. Malic acid is the main
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6. CIDER APPLES AND CIDER-MAKING TECHNIQUES 381

organic acid present in apples, ranging from 0.1 to 1.4%, with an average
of 0.5% (Beech and Carr 1977). Acid content of the source apples gives
cider its tartness and can be manipulated by the addition of more acid
(usually malic), neutralization of acidity by additions of calcium carbo-
nate, or addition of artificial (usually nonfermentable) or natural sweet-
eners to balance the acidity (Downing 1989). When fermentable sugars
are used to balance acidity, either pasteurization or preservatives may
be necessary to prevent fermentation after bottling (Mitchell 2006).
However, some French and Spanish ciders are intentionally bottled
(in containers that can withstand several atmospheres of pressure) with
residual sugars and active yeast, to provide natural effervescence (Rio
1997; Le Quere 2006).

1. Cider Acidity. The acidity of juice blends used for fermentation is

important, because it helps to control unwanted microbial growth.
Juice pH determines in part the amount of sulfites needed to inhibit
wild yeast growth, with more free SO2 required as the juice pH
increases (Beech 1972). Sulfur dioxide acts as a preventive antimicro-
bial agent before fermentation begins. It inhibits wild yeast growth and
allows for the pitched Sacharromyces strains (which are more resistant
to SO2 than wild yeasts and most of the potential spoilage micro-
organisms) to develop and dominate the fermentation (Jarvis and
Lea 2000). In addition to its antimicrobial effects, SO2 is a potent
antioxidant that can prevent juice oxidation and browning. However,
SO2 is effective only in its free or unbound form. Multiple compounds
that can be present in juice or cider, such as carbonyls produced by
decay organisms in fruit, can bind and inactivate SO2; therefore, it is
important to use clean, sound fruit for ciders. Patulin is another
potentially toxic by-product of spoilage organisms (primarily Penicil-
lium sp.) in rotten apples, but it is inactivated rapidly during the early
stages of alcoholic fermentation (Moss 1984).
The final pH and titratable acidity of cider play an important role in
stabilization and shelf life of the bottled product. Low acidity (pH > 3.8)
can lead to the growth of spoilage organisms and off-flavors (Lea and
Drilleau 2003). The final acidity also has a large impact on the flavor
profile of the cider; high acidity can make a cider seem harsh, usually
requiring some addition of sugar to balance its flavor. As with wines, a
secondary malolactic fermentation can be promoted in cider by adding
selected strains of lactic acid bacteria (Oenococcus oeni) to convert
some of the malic acid to lactic acid, which is perceived as less tart,
‘‘rounder,’’ and softer in the mouth (Jackson 2000). Final acidity levels
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382 I. A. MERWIN, S. VALOIS, AND O. I. PADILLA-ZAKOUR

for cider are recommended to be around 0.5% as malic acid (w/w) (Lea
and Drilleau 2003).

2. Cider Sugars. The main sugars in apples, in order of usual abundance,

are fructose, sucrose, and glucose. Fructose (7 to 11%) is usually two to
three times the amount of sucrose (2 to 4.5%) and glucose (1.5 to 3%)
(Beech 1972). Initial soluble solids (primarily sugars) levels can easily be
measured using a refractomer or hydrometer, and are directly propor-
tional to the amount of ethanol that can be produced during a complete
fermentation. Two grams of sugar are converted to 1g of ethanol and 1g of
carbon dioxide during anaerobic fermentation by yeast (Berry and
Slaughter 2003). In the United States it is important that the initial juice
contains less than 14% soluble solids (primarily sugars), so the resulting
cider will have an alcohol content of 7% or less; otherwise the final
product must be labeled as apple wine and is subject to a higher tax rate by
federal regulation (FDA: 27 CFR part 4). Additions of nonfermentable
sugars such as sorbitol or synthetic sweeteners such as aspartame,
acesulfame, and saccharin are permitted within limits set for other food
additives in the United Kingdom (Mitchell 2006), but are generally
discouraged or prohibited in other European cider industries. In France,
the final ethanol content in ciders is usually less than 4%, either by
regulation (for ciders sold under regional appellations) or by consumer
preference (for the nonappellation industrially produced French ciders).
Special treatments (described in detail later) are required to stop or slow
these fermentations to keep the ethanol content below, and the residual
sugar content above, the predetermined regulatory or gustatory thresh-
olds (Lee and Drilleau 2003).

3. Cider Tannins. As noted, apples contain a variety of secondary plant

metabolites that contain an aromatic ring and at least one hydroxyl group,
generally referred to as phenolics or tannins (Shi et al. 2003). Polyphe-
nolic compounds function in plants as defense mechanisms against
insects, bacteria, and fungi. They discourage fruit feeding due to their
harsh tastes; they bind with proteins and interrupt digestion in insects;
and they accumulate at plant-injury sites to help repair tissue and
prevent further pest penetration (Jackson 2000). Research has also sug-
gested that cider cultivars that are higher in phenolics than dessert apples
are more resistant to apple scab caused by Venturia inaequalis (Picinelli
et al. 1995). Polyphenolic compounds are also responsible for the inter-
nal and external color of many fruits (Machieux et al. 1990). The amount
of phenolic compounds in apples varies from year to year based on
cultivar, maturity, harvest time, orchard management style, weather, and
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6. CIDER APPLES AND CIDER-MAKING TECHNIQUES 383

other stress conditions that fruit may incur (Lea and Beech 1978; Lea and
Timberlake 1978; Machieux et al. 1990; Guyot et al. 2003; Boyer and Liu
2004; Valois et al. 2006).
Phenolic compounds are important nutritional or medicinal con-
stituents of many foods and beverages, and have been shown to
possess anticarcinogenic, anti-inflammatory, and antioxidant capaci-
ties (Prior and Cao 2000; Sun et al. 2002; Boyer and Liu 2004). The
dietary effects of plant phenolics have been the topic of intense
research activity recently, with hundreds of scientific reports, and
potentially great impacts on cider marketing. A recent pamphlet pub-
lished by the National Association of Cider Makers in the United
Kingdom extolled the health aspects of moderate cider consumption
and provided an extensive list of studies linking dietary antioxidants
with potential health benefits (Russell 2002). The potential benefits of
moderate consumption of ciders and other apple products have been
confirmed in many recent reports (DuPont et al. 2002). However, it is
difficult to quantify or generalize the benefits that may ensue from
consumption of polyphenolics and other antioxidants such as ascor-
bic acid in apples or ciders, because concentrations of secondary
metabolites in fruits are influenced by the terroir, or local site factors,
where they are grown (McGhie et al. 2005; Lila 2006), interacting with
the genetic traits and lifestyles of those who consume these fruit
products (Evans et al. 2006).
The major polyphenolic classes in apples are flavonols (quercetin),
flavan-3-ols (catechin and epicatechin), dihydrochalcones (phloridzin),
anthocyanins (cyanidin 3-glycosides), phenolic acids (chlorogenic
acid), and tannins/proanthocyanidins (polymers of catechin and epi-
catechin). Of these polyphenols, the only ones that are true tannins
(forming strong bonds with proteins), and produce an astringent or
bitter taste are the proanthocyanidins (Lea 1990a). Astringency is
defined as drying or puckering of the whole tongue, whereas bitterness
is defined as a sharp or stinging sensation at the sides or back of the
tongue (Lea and Timberlake 1978; Noble 2002). Frequently these terms
are used interchangeably due to sensory panelists and consumers’
inability to distinguish between the two stimuli in a given cider.
Research has shown that phloridzin may also contribute bitterness to
the flavor profile of ciders (Lea 1990b).
Polyphenolic compounds are degraded by oxidation occurring
mainly during milling or grinding, due to mash contact with air in the
presence of the enzyme polyphenoloxidase. Polyphenoloxidase (PPO)
is an enzyme that combines with the phenols creating melanin, better
known for its tanned color appearance. This browning can be prevented
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384 I. A. MERWIN, S. VALOIS, AND O. I. PADILLA-ZAKOUR

by inactivation of PPO or the elimination of oxygen. Ascorbic acid,

sodium bisulfite, or thiol compounds inactivate PPO by destroying
the active-site histadines or by removing copper from the site
(Lea 1990a). Heating can also inactivate PPO, and pasteurization of
apple juice can thus interfere with desirable color formation in sweet
or fermented ciders. Research at Cornell University (I. Merwin, unpubl.)
showed that delaying pasteurization of fresh cider for one day after
pressing improved its color and flavor development substantially, and
that very few consumers could distinguish between pasteurized and
nonpasteurized ciders after such a prepasteurization time delay. During
cider-making, the oxidation of phenolic compounds is expected, and
gives the cider its brown color, which may be lessened during fermen-
tation and with addition of sulfites.
Polyphenols are metabolized in fruit by enzymatic pathways regu-
lated by protein synthesis. In addition, other factors affect the rate of
production of polyphenols, such as light, temperature, and other growth
regulators (Machieux et al. 1990). Endogenous or applied growth regu-
lators can also affect the rate of maturation of the fruit and influence its
concentration of polyphenols, influencing other metabolic processes
such as ripening, fruit softening, and lignification.
Polyphenolic compounds also act as defense mechanisms against
herbivory and other stresses on the plant, such as diseases or pests
(Rhoades 1979), suggesting that high-tannin apple cultivars may have
increased resistance or tolerance to some orchard pests, compared with
dessert apples (Nicholson and Hammerschmidt 1992; Ju et al. 1996;
Michalek et al. 1998). A recent survey of pesticide usage in the United
Kingdom found that although cider and perry orchards comprised 25%
of total orchard area, they received just 8% of the total pesticides
applied during the study; 92% of dessert apple orchards received at
least one pesticide application, compared with just 60% of cider and
perry orchards, which is consistent with recommendations for substan-
tially reduced pesticide applications in cider orchards (Garthwaite et al.
2000; Umpelby and Copas 2002).
The types and amounts of phenolic compounds differ substantially
between cider and dessert apple cultivars. As mentioned, cider apples
are higher in phenolic content compared to dessert fruit. This increase
is due to the presence of different types of phenolic compounds as well
as increased amounts of compounds that are present in both types of
apples (Sanoner et al. 1999; Tsao et al. 2003). Phenolic compounds are
found throughout the fruit, but the majority are in the parenchyma
tissue (flesh), except for flavonols, which are found mainly in the
epidermis (skin) of the fruit (Guyot et al. 1998). Levels have been
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6. CIDER APPLES AND CIDER-MAKING TECHNIQUES 385

reported to range from 1,000 to 6,000 ppm (mg/kg fresh wt) and up to
10,000 ppm for selected cultivars used in cider production (Shahidi
and Naczk 2003). Chlorogenic acid and polymeric proanthocyanidin
content is also higher in cider fruit than dessert fruit (Machieux et al.
1990). Free hydroxycinnamic acids (chlorogenic, caffeic, ferulic, and p-
coumaric acids) are frequently present in cider after fermentation due to
hydrolysis by microbial action (Whiting and Coggins 1975). As noted,
the methods of pressing and fermenting ciders can also influence the
final concentrations of phenolics in the bottled products at the point of
consumption.

4. Aromatic Flavor Components. More than 130 volatile aromatic con-

stituents are present in small amounts in apples and ciders, and the
characteristic volatiles differ substantially among cultivars and in cider
apples compared with dessert apples (Hubert et al. 1990; Mangas and
Gonzalez 1996; Picinelli et al. 2000). The proportional volatile fractions
of apple juice average 49% alcohols, 36% esters, and 11% carbonyl
compounds; about half of these volatiles occur at greater than 1 ppm
concentrations in closed-container headspace at room temperature and
are usually below detection thresholds for humans (Acree and McLellan
1980; Calixto and Bermejo 1980; Williams and Lewis 1980). A recent
analysis of 90 French ciders, including both large-scale industrial and
regional small-scale artisanal types, showed that sensory perception and
chemical analysis of volatiles differentiated clearly between these two
types of cider, with the underlying differences attributed to use of
different apple cultivars, orchard practices, and fermentation methods
(LeQuere et al. 2006). A cider evaluation ‘‘flavor wheel’’ with clearly
defined aroma and taste descriptors is used in the United Kingdom
(Mitchell 2006), adapted from that developed by Noble et al. (1984) to
facilitate and standardize organoleptic evaluations of wine.

5. Cider Appearance. Visual aspects of cider can also influence con-

sumer perception and preferences, and ciders are made in a range of
styles including colorless or ‘‘white’’ ciders in England and cloudy or
turbid ‘‘farm style’’ ciders of England and France. Cider turbidity or
haziness can be due to soluble proteins, suspended yeast, or certain
spoilage organisms. Most large-scale producers aim for a clear or
‘‘bright’’ cider with light amber tones (achieved either by the presence
of oxidized tannins or by additions of caramel and other colorants), and
usually these ciders are filtered and clarified with bentonite or other
fining agents if necessary to remove visible haze or turbidity (Lea and
Drilleau 2003).
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386 I. A. MERWIN, S. VALOIS, AND O. I. PADILLA-ZAKOUR

II. ORCHARD SYSTEMS FOR CIDER APPLES

A. Modern versus Traditional Cider and Perry Orchards

Until about 1950, most European cider and perry orchards were silvo-
pastoral systems that received relatively few management inputs and
consisted of very large, long-lived trees planted at low densities. Tree
spacings were intentionally sparse (30 trees/ha was not uncommon),
and the scions were often high-budded several meters aboveground
onto seedlings or robust rootstocks such as ‘Bulmers Norman’ (Lea
and Drilleau 2003). Many of the traditional cider cultivars are relatively
vigorous, prone to biennial bearing, and have extensive ‘‘blind wood’’ or
nonbearing zones on the lateral branches (Williams 1987). These traits
may have been acceptable in traditional low-input orchards, but they
can be problematic in modern high-density intensively managed plant-
ings (Primault 1993; Dapena and Blazquez 1996; Copas 2001). Widely
spaced plantings of tall trees (Fig. 6.3) permitted adequate sunlight
penetration to support pasture growth for grazing livestock (Lombard
and Williams 1974; Merwin 1999). Since fruit did not need to be

Fig. 6.3. A traditional pasture cider orchard at Burrow Hill Cidery in Somerset, England.
Source: Photo from collection of I. Merwin 1998.
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6. CIDER APPLES AND CIDER-MAKING TECHNIQUES 387

cosmetically perfect for cider usage, farmers could apply few or no

pesticides and manage their plantings for grazing or forage crops while
still producing a marketable crop for cider production (Copas 2001).
In the 1950s, the French government subsidized the removal of tradi-
tional cider orchards, and by the 1990s, most growers and large-scale
cider-makers had replaced their old pasture orchards with modern
high-density plantings of a relatively few highly productive cultivars,
grafted on MM.106 rootstocks and managed more like commercial
dessert apple orchards (Desmarest 2004). In recent years, the organiza-
tion of regional appellations for cider and farm-cider trails have encour-
aged some small-scale growers and cider-makers to maintain or even
replant traditional high-budded (haut tige) orchards in France, ack-
nowledging the historical and cultural value of such orchards and their
cachet for establishing a favorable market image.
Similar transitions occurred in England during the mid-1900s, with
replacement of traditional orchards driven by economic forces and the
corporate policies of increasingly large-scale cider producers, such as
H.P. Bulmer in Herefordshire, which needed more reliable and consis-
tent sources of fruit to meet increased demand for their industrial-scale
cider production (Copas 2001). Since the 1990s, Bulmer, Thatcher,
Weston, and other large-scale cider-makers in England have contracted
with local growers, providing them with low-cost trees on size-
controlling rootstocks, technical support, and long-term contracts with
guaranteed minimum prices for certain Bittersweet and Bittersharp
apples grown in high-density orchards. As in France, these new high-
density plantings are usually managed in a relatively low-input strategy
requiring less pruning, fertilization, and pesticide input than compara-
ble dessert apple orchards (Umpelby and Copas 2002). Management
strategies are designed to maintain tree health and productivity, but are
based on tolerances and thresholds for cosmetic pest damage that
are much higher than in the dessert fruit industry (Williams 1987).
This situation makes cider orchards especially well suited for organic
or integrated fruit production (IFP) systems, but there is surprisingly
little published research investigating the specific pest management
practices suitable for cider orchards compared with dessert or culinary
apples.
For various reasons, in Spain more than any other region, cider
orchards have remained largely traditional in their systems and man-
agement. There is a large industrial cider-maker in Villaviciosa (El
Gaitero) that obtains most of its fruit from picturesque local Asturian,
Galician, and Cantabrian orchards that are managed in much the same
way that they were a century ago—large trees of local landraces, planted
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388 I. A. MERWIN, S. VALOIS, AND O. I. PADILLA-ZAKOUR

far apart in pastures on small hillside farms (Sanchez et al. 1991). With
the renaissance of provincial cultural traditions and increased inde-
pendence from the central government in Spain, indigenous cider
traditions have become more important in provinces such as Asturias
and the Basque Country, and the image of old-fashioned orchards and
cider-making techniques has been promoted (Sanchez et al. 1991; Rivas,
2004).

B. Cultivar Characteristics
From an orchard management perspective, many of the Bittersweet and
Bittersharp cider cultivars differ substantially from the common dessert
and culinary apples in such important traits as biennial bearing, uneven
ripening, delayed blooming and ripening, tendencies to set fruit in
heavy clusters, and relative lack of response to chemical thinning treat-
ments (Williams 1987; Fuertes et al. 1997; Merwin, 1999). These differ-
ences may be related to the selection processes imposed by humans
during the domestication of apples primarily used for cider. Many cider
cultivars tend to drop a high proportion of their fruit on the ground
during the maturation and ripening periods. This trait may be advanta-
geous in that it reduces harvest labor requirements and facilitates
mechanical collection of drops in modern large-scale cider orchards
(Sanchez et al. 1991), but it presents a problem in the United States,
where mechanical harvesting equipment is not readily available and
phytosanitary rules developed for fresh or processing apples prohibit
the use of dropped fruit unless the juice is pasteurized or irradiated.
Pronounced biennial bearing is characteristic of many traditional
cider cultivars and is often one of the traits noted in recommending
cultivars for production (Williams 1987; Boré and Fleckinger 1997;
Copas 2001). Fruit size is usually smaller for cider apples compared
with dessert or culinary apples, and the fruit tend to set in compact
clusters with five or more per spur, causing numerous push-offs from
the clusters as fruit gain size approaching harvest. As noted, many of the
cider cultivars bloom much later than common dessert or culinary
apples. Even within the category of cider apples, there are some culti-
vars that bloom along with standards like ‘Golden Delicious’ or ‘Gala,’
while flowering of others is delayed a month or more (Morgan and
Richards 1993; Boré and Fleckinger 1997). Because timing is so
critical for effective chemical thinning, it is important for growers to
consider bloom times when planting cider orchards. Early- and late-
blooming cultivars should be planted together, to provide adequate
cross-pollination and facilitate applications of chemical thinners at
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6. CIDER APPLES AND CIDER-MAKING TECHNIQUES 389

the appropriate time for each cultivar. Williams (1987) suggested group-
ing more and less difficult-to-thin cultivars together for purposes of
chemical thinning and stressed the importance of crop load reduction
in the first bearing years, because biennial tendencies of many cultivars
were difficult to break once established.
One of the authors of this review (Merwin) has been assessing cultivar
responses to chemical thinners for the past six years in a high-density
orchard with 25 traditional English and French cider cultivars on M.9
and Bud.9 rootstocks, trained in vertical axe form. This work is still in
progress, but it indicates to date that even with properly timed appli-
cations at recommended concentrations using carbaryl, napthaleneace-
tic acid, and benzyladenine fruit thinners (Agnello et al. 2005), many of
the traditional cider cultivars are difficult to thin adequately and some
may crop biennially even when they are hand-thinned. There has been
little research published on this topic in Europe; most of the cider-apple
growers whom the authors have interviewed expect and accept sub-
stantial year-to-year variation in production from some of the traditional
cultivars. However, the list of recommended cultivars for modern plant-
ings in Europe does reflect biennial-bearing tendencies, and growers are
encouraged to plant the more annual-bearing cultivars when feasible
(Williams 1987; Boré and Fleckinger 1997; Fuertes et al. 1996).

C. Orchard Nutrition and Cider Quality

The newer intensive orchards in France and England are more often
fertilized with nitrogen and potassium than the traditional pasture
orchards, and a review of N content in French ciders from 1950 to
1985, during the transition from traditional to high-density plantings,
showed a marked increase in N content (Drilleau 1993). This trend has
led to concern that fruit from modern orchards may have lower poly-
phenolic content compared with traditional orchards, based in part on a
study by Lea and Beech (1978). This experiment used 33-year-old trees
on MM.106 rootstocks that were transplanted into pots to reduce other
variables, and subjected to fertilized (N and K) or unfertilized treat-
ments. Fruit from the fertilized trees contained more N and less tannin,
and a sensory panel was able to distinguish ciders made from this fruit,
based on their relative astringency and bitterness. Since this study,
many cider-makers have assumed that N fertilization reduces phenolic
content in apples, but few other published studies have confirmed or
refuted this assumption.
The N content of French ciders is of special concern because of their
unique methods of producing ciders with unfermented residual sugar,
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390 I. A. MERWIN, S. VALOIS, AND O. I. PADILLA-ZAKOUR

achieved through stalled fermentations by limiting the yeast-available

N. For cider-makers generally, low-N juice is more prone to develop off-
flavors due to reduced sulfur compounds if the yeasts lack sufficient N.
As noted earlier, the N content of apples is thus a complex issue with
various positive and negative impacts on cider quality (Lea and Drilleau
2003).
Recent research by Valois et al. (2007) in a young high-density New
York orchard of 9 traditional English Bittersweet cultivars on 3 different
rootstocks (M.9, G.16, and CG.30), growing in a glacial till soil with
relatively high intrinsic N release (about 80 kg Nha1 yr1), showed no
short-term effects of side-dressed ammonium nitrate fertilization on
fruit N or polyphenolics content, with fertilizer N ranging from 0 to
90 kg N ha1 in single or split applications. Hutchinson et al. (1959)
reported an increase in phloridzin with increased apple N supply, but
no effects on concentration of other phenolic compounds. Another
study showed no differences in juice N content from fertilized versus.
unfertilized trees, but this could be attributed to the timing of N appli-
cations (Burroughs and May 1959). Yet another study showed that N
content varied with tannin or phenolic content in apples, but the
investigators did not impose treatments to manipulate tree N content;
they merely analyzed N concentrations in leaves and correlated these
with chemical analyses of the fruit during four years of observations
(Kvale 1969). Orchards with elevated N status often produce larger
apples with decreased flavor and red coloration (Wargo et al. 2003),
suggesting that excess N may inhibit the production of polyphenolic
compounds involved in color and flavor (Lea 2004). Because apple
polyphenolics are also associated with beneficial antioxidants
(Nagasako-Akazome et al. 2004), orchard nutritional status may have
important implications for human health and nutrition as well as cider
quality. More research is needed regarding the relationship between
apple polyphenolic concentrations and environmental conditions or
management practices in orchards.
Another potentially important aspect of cider and perry orchard N
fertilization involves tree susceptibility to fire blight caused by Erwinia
amylovora. This disease originated in North America; it was introduced
to Europe several decades ago, and has since become a major problem in
apple and pear orchards there (Chartier et al. 1992; Paulin and Primault
1993). The bacterium that causes fire blight spreads more rapidly in
succulent young wood that is typical of trees with high N status (van der
Zwet and Beer 1995). Compared with dessert apples, many of the cider
cultivars bloom much later in the spring than standard cultivars such as
‘Golden Delicious’ (Morgan and Richards 1993; Boré and Fleckinger
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6. CIDER APPLES AND CIDER-MAKING TECHNIQUES 391

1997). Erwinia amylovora has a relatively high metabolic temperature

threshold and multiplies most rapidly in the nectaries of apple and pear
flowers at temperatures of 24o to 29oC (van der Zwet and Beer 1995).
Because ambient temperatures normally increase from late spring to
early summer, the late-blooming trait of many cider apples makes them
especially vulnerable to fire blight infections.
The advent of fire blight throughout Europe has been especially
problematic in the perry-pear orchards of England and France (Mitchell
2006). Traditional perry cultivars are robust and long-lived trees, and
some enormous perry trees more than 300 years old remain in produc-
tion, interspersed with cider orchards in southwest England (Luckwill
and Pollard 1963; Copas 2001). Many of these pear trees are 15 m
or more in height, making it difficult to apply protective bactericides
for fire blight control. As a consequence, some venerable perry-pear
orchards have succumbed to fire blight in recent decades. Fire blight,
combined with the technical challenges of making perries of consistent
quality (Mitchell 2005), has furthered the decline of perry as a tradi-
tional fermented drink.

III. NATIONAL AND REGIONAL CIDER CULTURES

AND CULTIVARS

Cider consumption has increased substantially since 1990 in Spain,

France, the United States, and the United Kingdom. In parts of these
countries, cider has become an economically important food-beverage
sector and a profitable agrotourism attraction. The European Union (EU)
has recognized the importance of cider for income generation and
stabilization of rural communities, and provided subsidies to improve
infrastructure and capacity for cider-making in several countries. This
strategic support has revitalized regional cultures and economies of
cider-making: Restaurants and special sidrerias (cideries) feature cider
and apple cuisine; bed andbreakfasts and on-farm guest houses cater
to cider tourists; and local cider-makers host visitors at on-farm tastings
along regional routes des cidres (cider trails). A wide range of ciders
are available to satisfy every preference or niche market—ranging from
cheap high-alcohol drinks for so-called hooligans, to rough scrumpies
for the seasoned farmer (Fig. 6.4), or diverse and distinctive cidre
bouché (literally, ‘‘corked ciders’’) consumed in trendy French restau-
rants or creperies that specialize in buckwheat pancakes stuffed with
local cheeses and sausages, paired with distinctive artisanal ciders
(Fig. 6.5). In this section we review briefly the historical development
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392 I. A. MERWIN, S. VALOIS, AND O. I. PADILLA-ZAKOUR

Fig. 6.4. Breton farmer enjoying cider in the traditional drinking utensil of that region,
around 1898. Source: Photo from collection of I. Merwin, taken at Cider Museum in
Pleudihen, France, 1998.

and current situation for cider in each of these countries and world
regions.

A. France
Cider apples first appear in the written history of northern France in the
11th century CE, and widespread cider production began during the
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6. CIDER APPLES AND CIDER-MAKING TECHNIQUES 393

Fig. 6.5. Selection of local artisanal ciders on the menu at a restaurant in Normandy,
France. Source: Photo courtesy of Pays de Normandie Magazine (May-June 1997).

following century (Warcollier 1926). These apples were notable for their
high polyphenolic or tannin content, in contrast to the more acidic and
less tannic native M. sylvestris crabapples. The early French cider
apples were probably not indigenous landraces and may have origi-
nated elsewhere in Europe during the 10th century or earlier. The
French historian Chevalier (1921) speculated that the Basque Country
in northeast Spain was a probable site of origin for cider cultivars,
noting that the Basque peoples were one of the oldest ethnic groups in
Europe, preceding the Celtic inhabitants of northern Spain, and that the
word for cider in Basque is sagara, which may have provided the root for
the Latin word sicera, connoting sidra in Spanish, cidre in French—
hence cider in the English language (French 1982; Boré and Fleckinger
1997).
The systematic study of cider apples in France began in earnest
during the late 1500s, when Jacques Cahaignes described 65 different
cider cultivars grown in Normandy. When Duhamel de Monceau pub-
lished his ‘‘Treatise of Fruit Trees’’ in 1768, there were about 300 named
cultivars in that region. In the 1950s, Fleckinger and his colleagues in
France proposed a systematic method for describing and classifying
cider apples, and began to collect and study the French cultivars first at
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394 I. A. MERWIN, S. VALOIS, AND O. I. PADILLA-ZAKOUR

Versailles and then at the INRA facility in Angers. Among the 1,000 or
so cultivars that were collected, characterized, and observed over many
years, they have published detailed physical and chemical descriptions
of 350 main cultivars (Boré and Fleckinger 1997). About 70 elite culti-
vars are now recommended for cider production in France (Table 6.2),
differentiated by region based on their high juice yields, tree produc-
tivity and reliability, disease and pest tolerance, and the useful qualities
they impart to ciders.
Four main regions represent 95% of the cider production in France
today: Upper and Lower Normandy, Bretagne, and the Loire Valley.
There are three main categories defined for cider in France: Cidre
fermier (farm-style cider) is produced on-site from apples grown at the
farm itself (as in the estate-winery concept); cidre bouché is produced
by regional artisans from traditional cultivars of each region, and usu-
ally is bottle-conditioned with some residual sugars and natural effer-
vescence. Many artisanal cider-makers market their products under
appellation d’origine controlée (AOC) labels, following rules that pro-
hibit chaptalization (additions of refined sugar to the fermentation), the

Table 6.2. List of cultivars recommended for cider production in Asturias, Spain,
with growing characteristics and blending categories.

Recommended Cultivars Growth Characteristics Blend Category

Blanquina High vigor Full Sharp

Cristalina Vigorous Semi-Sharp
De la Riega Med. vigor Semi-Sharp
Limón Montés Med. vigor Full Sharp
Marialena High vigor Semi-Sharp
Regona Low vigor Full Sharp
Panquerina Low vigor Sharp
Prieta Med. vigor Sharp
Raxao High vigor Full Sharp
Solarina Med. vigor Semi-Sharp
Teorica Low vigor Sharp
Durón Arroes Med. vigor Sweet
Perezosa Med. vigor Sweet
Verdialona Med. vigor Sweet
Peau de Chien Low vigor Bittersweet
Coloradona Med. vigor Bittersweet
Picona Rayada Med. vigor Mild Bittersweet
Collaos Med. vigor Mild Bittersharp
Perico High vigor Mild Bittersharp
Xuanina Med. vigor Mild Bittersharp

Source: Adapted from Sanchez 1991; Fuertes et al. 1996.

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6. CIDER APPLES AND CIDER-MAKING TECHNIQUES 395

use of apple juice concentrate, sulfite additions, yeast inoculations, and

artificial preservatives in the finished product (Lee and Drilleau 2003).
The so-called industrial (as opposed to artisanal) ciders of France
account for most of the national production, including some 80 million
l of inexpensive cider marketed through supermarkets and restaurants
without regional appellations. At present, 11 cider cultivars comprise
75% of the planted area in France (in descending order): ‘Douce Moen’,
‘Douce Coet Ligne’, ‘Judor’. ‘Petit Jaune’, ‘Judeline’. ‘Juliana’. ‘Binet
Rouge’, ‘Judaine’. ‘Kermerrrien’. ‘Avrolles’. and ‘Clos Renaux’ (Boré
and Fleckinger 1997). Recent statistics for French cider production
(Info-Cidre.com) indicate that national consumption is about 110 mil-
lion l—66% purchased in major retail markets and 34% in regional
creperies, hotels, restaurants, or directly from the cider-makers—of
which 47% is produced in Normandy, 35% in Brittany, and 13% in
the Loire Valley region. Despite the prominence of artisanal cider-
makers in regional agrotourism, 10 large-scale industrial producers
account for 85% of the cider made in France at present.
Cider production systems and styles in the EU countries are broadly
regulated by the Associated Industries of Ciders and Wines (AICV:
www.aicv.org). Within each country, more specific rules and regula-
tions are set by national governments and producer organizations. In
France and Spain, provincial governments set local regulations and
label restrictions, including rules based on the general concept of
‘‘terroir’’ that stipulate which geographic region can be mentioned on
product labels—the so-called Protected Geographic Indication (PGI)
rules of the EU (Mitchell 2006). In France, there are at least 10 different
permitted labels and legal definitions for cider (Info-Cidre.com). For
example, AOC denominations specify ‘‘Pay d’Auge’’ and ‘‘Cornouaille’’
ciders from regions in Normandy and Brittany; another ‘‘AB,’’ or bio-
logical agriculture, label specifies ciders made using organic methods.
Emulating the Beaujolais nouveau market, there is even a cidre nouveau
label designating newly made ciders sold between October and March
each year.
A defining characteristic of artisanal French cider-making is the
practice of keeving (called defecation in French) that can be combined
with centrifugation, to diminish the amount of nitrogen and yeast
activity in their ciders, to control tannins, and to help clarify the final
product. Keeving is a difficult and somewhat unpredictable process, but
it can be useful for slowing or stalling fermentation in order to make a
cider with a some residual sugars (Lea 1995). After the mash is pressed
for keeving, the juice is kept at 58C to encourage pectin methyl esterase
(PME) activity, which is naturally present in the fruit and can also be
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396 I. A. MERWIN, S. VALOIS, AND O. I. PADILLA-ZAKOUR

added for increased activity. The PME removes methyl groups from the
pectin molecule, allowing other divalent ions such as calcium to bond
in the methyl group’s place. The de-methylated pectin can then com-
bine with calcium, proteins, or asparagines in the juice, forming a gel
(known in French as the chapeau brun, or ‘‘brown hat’’) that floats to the
top of the barrel as CO2 gas is released during incipient fermentation. At
the same time (if all goes well), some solids settle to the bottom of the
barrel leaving a clear juice in the middle, which has been diminished in
nitrogen. This practice involves some risk, because it increases the
likelihood of reduced sulfides and other off-flavors caused by metabolic
stress of yeasts coping with low N levels (Le Quere et al. 2006). How-
ever, keeving is customary in artisanal cider-making, and when suc-
cessful it can produce naturally sweet and effervescent ciders with
enhanced fruity volatiles. French cidre bouché drinkers have come to
accept and appreciate this type of finished product. Another French
technique that enhances residual sugars and slows yeast fermentation
involves repeated centrifugation or ‘‘biomass reduction’’ to remove
and suppress the remaining yeast in traditional cider styles (Lea and
Drilleau 2003). These practices are necessitated by restrictions on the
use of additives or amendments in artisanal French ciders and are part
of the reason for its renewed market appeal.
The French also produce Calvados (in Normandy) and similar dis-
tilled apple ‘‘brandies’’ in other regions (Robin and de la Torre 1987). As
in the distinction between Cognac and brandy, or Champagne and other
sparkling wines, the term Calvados, strictly speaking, refers exclusively
to a distilled cider produced from the fermented juice of selected apple
cultivars traditionally grown in Normandy (Mattson 2005). Distillation
can only be done in alembic copper stills, and requires successive
passes through these stills to obtain the desired alcohol level and
fractionation of volatiles. The distilled product is then aged in barrels
of French oak for a designated number of years, diluted to 40% (v/v)
ethanol with water, and marketed as Calvados at premium prices. The
predominant flavors and amber color of Calvados and similarly pro-
duced apple brandies are derived from the oak barrel aging as well as
from the cider.
A different fermentation and distillation process produces eau de vie
that retains many of the characteristic aromatic traits of the source fruit
cultivars (Ortner 1996). The best apple eau de vies are made by ferment-
ing crushed fruit or pomace as a mash, without pressing off the juice
(Tanner and Brunner 1982). By definition, most aromatic flavors are
volatile, and in fermenting cider much of the characteristic aroma of the
varietal blend is lost to the head space in fermentation vessels and
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6. CIDER APPLES AND CIDER-MAKING TECHNIQUES 397

vented to the atmosphere along with the outgoing CO2. This loss of
characteristic apple volatiles during fermentation of juice sometimes
makes it difficult for most consumers to identify the source fruit as
apples in the finished product, and often the ‘‘fruity’’ notes in cider
are derived as much from the particular yeast strains involved as from
the apples themselves (Lea and Drilleau 2003). In a fermenting mash,
more of the aromatics released from cellular breakdown, hydrolysis of
soluble solids, and the yeast itself are retained in the solid matrix of
pulp. When the fermentable sugars have been fully depleted from the
mash, the solid/liquid mixture is transferred to copper mash stills with
internal stirring paddles, designed specifically for such distillations.
Gentle stirring and steam heating vaporizes the ethanol along with some
of the desirable aromatic substances including phenolics, esters, and
aldehydes; at the same time, undesirable components such as fusel
alcohols are removed from the distilled product by condensation and
drip back down into the remaining mash.
Unlike most apple brandies, properly fermented and distilled eau de
vies retain the signature aromatics and flavors of the original fruit
cultivars (Claus and Berglund 2005). Those familiar with aromatic
apples such as ‘Jonagold’. ‘Cox Orange Pippin’, or ‘Bartlett’ (‘Williams’.
pears can readily identify their derivative eau de vies by sniffing the
head space of a sampling glass. Distillation of eau de vies from fer-
mented apple, pear, apricot, plum, peach, and cherry is also an impor-
tant and popular activity in eastern Europe, but that is beyond the scope
of this review. A comprehensive technical review with guidelines
for small-scale distillation of eau de vies is presented in Tanner and
Brunner (1982).
The French government supports two research and technical support
centers for cider-makers, near Rennes in Brittany and at Sées in Lower
Normandy. The National Institute of Agricultural Research (INRA)
maintains a comprehensive germplasm collection and pursues descrip-
tive studies of cider cultivars in Angers. Current priorities of these
research centers are the chemical characterization of ciders and cider
apples, studies of the health benefits of cider, and technical support for
cider apple growers (www.ctpc.cidre.net). France is the only nation to
develop a series of modern cider cultivars through scientific breeding,
selecting cultivars improved for disease resistance, chemical character-
istics, precocity, and productivity (Boré and Fleckinger 1997). The
patented cultivars of these series—most of which have names beginning
with Ju- (e.g., ‘Judor’. ‘Judeline’. ‘Juliana’. etc.)—are widely grown and
well adapted for high-density plantings and industrial cider produc-
tion, although the genetic resistance of ‘Judeline’ and some other
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398 I. A. MERWIN, S. VALOIS, AND O. I. PADILLA-ZAKOUR

cultivars to Venturia inaequalis has failed as the pathogen developed

resistant races able to overcome some of the naturally occurring apple-
scab resistance genes in Malus sp.

B. Spain
Traditional cider apples are grown primarily along the north coast of
Spain, in the cool maritime climate regions north of the Picos de Europa,
a western extension of the Pyrenees mountain range. Unlike the rest of
Spain, these northern provinces were not conquered by the Moors, and
they retain a distinctly Celtic culture to this day. Spanish and Basque
cider apples may be some of the most ancient local M.
domestica
lineages in Europe, and Asturian cider orchards were first mentioned in
records of the monastery of San Vicente in Oviedo in the year 781 CE
(Sanchez et al. 1991). To this day, Spain retains a unique and distinctive
cider culture and industry, with its own local cultivars, its own cider
styles, and a vibrant cultural scene that draws Spanish and other tou-
rists to the cool north coast to visit sidrerias and enjoy the local cuisine
and splendid rural scenery while the rest of Spain endures scorching
summer heat. A research center devoted primarily to cider apples and
fermentation is located at Villaviciosa in Asturias, where Spain’s largest
industrial cider-maker (El Gaitero, Spanish for bagpiper) is located.
Apart from El Gaitero—which produces carbonated, semisweet ciders
with substantial acidity that are marketed as an inexpensive substitute
for sparkling wine throughout Spain and South America—most
Spanish cider-makers on the north coast are small-scale regional pro-
ducers using traditional methods and local cultivars (Rivas 2004). An
excellent museum for Spanish ciders is located in La Nava, Asturias
(www.museodelasidra.com). As in France, most of Spain’s cider apples are
traditional landrace selections that have been grown locally for many cen-
turies. A list of the main Asturian cider apples and their characteristics is
presented in Table 6.3 (Sanchez et al. 1991; Fuertes et al. 1996).
Traditional-style Spanish ciders are sold primarily through a network
of regional sidrerias—pub-style restaurants that feature the ciders of a
few local producers in combination with regional cuisine. These ciders
are usually still (fermented to dryness without effervescence), with
relatively low tannin content; they are relatively tart, with substantial
volatile acidity due to exposure to oxygen and the presence of acetic
acid-forming bacteria during fermentation (Suarez et al. 1996). They are
sold in 750-milliliter (ml) bottles that can usually be distinguished only
by the producer’s stamp on the corks, and individual sidrerias often
feature the ciders of a just a few local producers.
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6. CIDER APPLES AND CIDER-MAKING TECHNIQUES 399

Table 6.3. List of nationally and regionally recommended cultivars for cider
production in France, by region and blend category of apple. Some AOC designations
require use of certain cultivars within these broad categories.

Blending Blending
Cultivar Category Cultivar Category

Generally Recommended
Avrolles Sharp Frequin Rouge Bittersweet
Bedan Bittersweet Judor Sharp
Binet Rouge Bittersweet Judeline Sharp
Bisquet Bittersweet Kermerrien Bittersharp
Cidor Bittersweet Locard Vert Sharp
Clos Renaux Sweet Marie Menard Bittersharp
Douce Coet Ligne Sweet Petit Juane Sharp
Douce Moen Bittersweet
Regionally Recommended
Amere Saint Jacques Bittersweet Guyot Roger Sweet
Antoinette Bittersweet Herbage Sec Bittersweet
Armagnac Bittersharp Juane de Vitré Sharp
Avalou Belein Bittersweet Jeanne Renard Bittersweet
Belle Fille de la Manche Bittersweet Joly Rouge Bittersweet
Bergerie de Villerville Bittersweet Judin Sharp
Binet Blanc-Doré Bittersweet Maltot Sweet
Binet Violet Bittersweet Mariennet Bittersharp
Blanchet Sharp Marin Onfroy Gros Bittersweet
C’huero Briz Bittersweet Mettais Bittersharp
Cartigny Bittersweet Monnier Dur Bittersweet
Chevalier Juane Bittersweet Moulin a Vent Bittersharp
Chuero Ru Bihan Bittersharp Muscadet de Dieppe Bittersweet
Cimetiere de Blangy Bittersweet Noel des Champs Bittersweet
Clozette Douce Bittersweet Omont Bittersweet
Crollon Bittersweet Petit Amer Bittersweet
Diot Roux Sharp Rambault Sharp
Domaines du Calvados Bittersharp René Martin Sharp
Douce Bloc Hic Sweet Rouge de Trêves Sharp
Doux au Gobet Sweet Rouge Duret Sweet
Doux Eveque Juane Sweet Rousse de la Sarthe Sweet
Doux Joseph Bittersweet Saint Philbert Bittersweet
Doux Lozon Bittersweet Sebin Blanc Sharp
Doux Veret de Carrouges Sweet Solage a Gouet Bittersweet
Ègyptia Bittersweet Saint Martin Bittersweet
Fil Juane Sharp Sorte Petite de Parc Dufour Sweet
Grise Dieppois Bittersweet Taureau Bittersweet
Groin D’Âne Bittersweet Teint Frais Bittersharp
Gros Bois de Bayeux Bittersweet Tesnières Sharp
Guillevic Sharp Tête de Brebis Bittersweet

Source: Primault 1993; Bore and Fleckinger 1997; CTPC Web site at http://ctpc.cidre.net.
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400 I. A. MERWIN, S. VALOIS, AND O. I. PADILLA-ZAKOUR

Spanish ciders are served in a very distinctive manner by an escan-

ciador, usually the bartender, holding the bottle high overhead in one
hand and pouring a small volume (about100 centiliters) of cider skill-
fully (one hopes!) into a large crystal glass held at an acute angle, as low
as possible in the other hand. Aside from the dramatic display involved,
pouring still ciders in this fashion aerates them and volatizes their
characteristic aromas, enhancing the appreciation of their flavors. Local
ciders are often fermented in very large chestnut or oak barrels (toneles)
that may hold up to 10,000 l. These tanks are filled sequentially with
juice as the harvest season progresses, so that each barrel contains cider
from apple cultivars that were harvested within a narrow time frame
(Aramburu 1991). This method of fermentation leads to unique ciders in
each barrel and requires careful blending among different barrels to
produce consistently ciders that are characteristic of the individual
cider-maker from one year to another. In selecting the right lots for each
blend, the cider-maker extracts a small plug from the head of each barrel
and catches the resultant high-pressure jet of cider in a tasting glass
(Fig. 6.6), a cultural flourish that also brings out the full flavors and
facilitates the evaluation and blending of each cider.
Three major germplasm repositories in Galicia, Asturias, and Euskadi
(the Basque Country) have collected and characterized their local apple
cultivars for both dessert and cider usage. The repository at Mabegundo
contains some 400 Galician cultivars, many of which are used mostly
for cider production. Recent genetic studies using isoenzymes and
satellite markers (SSRs) have authenticated the genetic lineages and
regional groupings of these local apples and characterized their traits
for cider and fresh market utilization (Pereira-Lorenzo et al. 2003).
Another repository at the SERIDA center in Villaviciosa includes about
800 local and international apple accessions, of which several hundred
are used primarily in cider production (Dapena and Blazquez 2003).
Recent breeding research at the Villaviciosa repository has suggested
that useful sources of polygenic resistance to apple scab and other
diseases and arthropod pests may be present in the local cider apple
cultivars—a possibility that would be consistent with farmer selection
over many centuries of apple cultivars that could survive and produce
fruit for cider-making without pesticide treatments (Piccinelli et al.
1995).
Several provinces in Spain have recently promulgated strict defini-
tions and controls over cider-making. Basically, these regulations
require growing certain characteristic cultivars in each province, har-
vesting and handling the fruit in certain ways, and limiting additives or
processing of the finished ciders. In Asturias, two strictly defined
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6. CIDER APPLES AND CIDER-MAKING TECHNIQUES 401

Fig. 6.6. Sampling a barrel-fermented Asturian cider in the traditional manner, at the
Sidreria Miravalles in Villaviciosa, Spain, prior to blending among barrels for quality and
consistency. Source: Photo from collection of I. Merwin 1998.
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402 I. A. MERWIN, S. VALOIS, AND O. I. PADILLA-ZAKOUR

categories of cider are permitted (www.sidradeasturias.es/docs/es/

legislacion/reglamento), both of which must be derived solely from
the juice of apples (i.e., no juice concentrates are permitted): ‘‘Sidra’’
must have a minimum alcohol content of 5% and can be labeled as
‘‘dry’’ with<30 g sugar/L, ‘‘semi-dry’’ with 30 to 50 g sugar/l, and
‘‘sweet’’ with 50 to 80 g sugar/l. The second category is ‘‘sidra natural’’
(natural cider) and must be derived exclusively from traditional cider
cultivars of each region, produced using traditional methods, with no
permissible additions of sugar, yeast, or artificial carbonation. The
former category includes industrial ciders of El Gaitero in Villaviciosa
and some of the larger regional producers in Galicia and the Basque
Country; the latter category includes most smaller traditional growers
and cider-makers in each region.

C. The United Kingdom

The United Kingdom is by far the world’s biggest cider producer and
market, with more than 500 million l of cider and perry consumed in
2004, mostly produced in the southwestern part of England (Mitchell
2006). Some very large orchards linked with the major cider-makers,
located in Wales, Somerset, Hereford, Worcester, and Gloucester,
account for most of the apple and cider production in England (Fig.
6.7). These regions have relatively warm and dry growing seasons
compared to the rest of England, making them especially well suited
for orchards (Copas 2001).
At the time of Roman conquest, the indigenous Anglo-Saxons were
already fermenting ciders from their native crabapples (Mitchell
2006). A few millennia later, cider remained a regionally diverse
and popular product of small farms in England (Worlidge 1685), but
it experienced the same decline in reputation and consumption that
occurred in France during the late 1800s (Morgan and Richards 1993).
The renowned horticulturist Thomas A. Knight—considered to be
the first scientific plant breeder—was involved in the heyday of Eng-
lish ciders during the late 1700s. Knight made what was (arguably) the
first controlled pollination cross of selected parents, using ‘Golden
Pippin’ from his own West Midlands orchard in the 1790s. Knight’s
Pomona Herefordiensis, published from 1808 to 1811, provided the
first systematic descriptions of English cider cultivars. Influential
aristocrats such as Lord Scudamore also promoted cultivar selection
and improvement of English ciders during the 1700s. The fortunes of
English and French cider-makers ebbed and flowed as prolonged wars,
embargoes, and newly introduced grape pests such as Phylloxera and
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6. CIDER APPLES AND CIDER-MAKING TECHNIQUES 403

Fig. 6.7. Mechanical harvest of apples from the ground in a modern English cider orchard
(photo courtesy of NACM). Source: Photo reproduced from Umpelby and Copas 2002.

downy mildew (Plasmopara viticola) restricted the availability of

wine.
As the English countryside was depopulated and resettled into new
industrial centers, beer replaced cider as the national drink (Morgan and
Richards 1993). In 1887, Percy Bulmer founded what would become the
world’s largest cider-maker—H.P. Bulmers, in Hereford. Today, the
Bulmer cidery (now owned by Scottish & Newcastle Brewing Co.)
remains preeminent, producing 65% of the United Kingdom’s cider in
a range of styles including kegs, bottles, and six-pack cans (Mitchell
2006). Another milestone in English ciders occurred in 1903, when the
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404 I. A. MERWIN, S. VALOIS, AND O. I. PADILLA-ZAKOUR

National Fruit and Cider Institute was established in Long Ashton (near
Bristol). For the next 80 years, Long Ashton remained a leading center
for research and technical support to the English cider industry, indi-
rectly benefiting cider-makers worldwide until it was eviscerated dur-
ing the era of Prime Minister Margaret Thatcher and subsequently
closed down.
At present, the English cider sector is dominated by 10 large-scale
cider-makers that have formed the National Association of Cider Makers
(NACM) to promote cider production and consumption (www.cider-
uk.com). However, many small-scale cider-makers also exist in south-
west England, with various cider trails, local styles, and regional
cultivars (Bruning 2005). Compared with Spain or France, relatively
few cider apple cultivars are grown in England, and many of their names
suggest that they probably originated in Brittany, Normandy, or the
Channel Islands (Table 6.4). A very readable and thorough summary
of the traditional English cider apples, with color plates and complete
descriptions of 88 cultivars, was published recently by Liz Copas
(2001). The descriptions in this monograph are especially useful for
North American growers who need to verify the authenticity of some
imported cider cultivars, because there have been misidentifications of
accessions in the U.S. Department of Agriculture Malus germplasm
repository at Geneva, New York, that were subsequently propagated
and distributed by commercial nurseries in the United States.
The English cider industry is less closely regulated than those Spain
and France with respect to its permitted styles of cider-making and
marketing. Cider and perry are defined in the United Kingdom accord-
ing to the most basic criteria of the AICV, as fermented apple (or pear)
juice or blends including juice concentrate, with an alcohol concen-
tration between 1.2 and 8.5% (v/v), without added distilled spirits,
colorants, or flavorants. A detailed list of permitted additives and ingre-
dients in English ciders is available in Mitchell’s (2006) NACM hand-
book.

D. North America
Wherever apples are grown, unfermented or ‘‘sweet’’ or ‘‘fresh’’ cider
has persisted as a local drink in the United States and Canada. With
globalization of the world apple market, direct sales have become
increasingly important for many U.S. apple growers (O’Rourke 1994),
and small retail outlets or farm stands often feature fresh-pressed cider
to attract customers and increase purchases of fruit or other farm and
kitchen produce (Rowles, 2000). Recent outbreaks of food poisoning
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6. CIDER APPLES AND CIDER-MAKING TECHNIQUES 405

Table 6.4. Recommended cider apples in each blend category for the UK cultivars
designated as dual purpose can be used for culinary or dessert purposes in addition to
cider blends.

Generally Generally
Recommended Recommended Blending
Cultivars Blending Category Cultivars Category

Broxwood Foxwhelp Bittersharp Sweet Coppin Sweet

Bulmers Foxwhelp Bittersharp Woodbine Sweet
Cap of Liberty Bittersharp Ashton Brown Jersey Mild bittersweet
Dymock Red Bittersharp Brown Snout Mild bittersweet
Kingston Black Bittersharp Dove Mild bittersweet
Lambrook Pippin Bittersharp Hangdown Mild bittersweet
Neverblight Bittersharp Thomas Hunt Mild bittersweet
Porter’s Perfection Bittersharp Tremlett’s Bitter Mild bittersweet
Stoke Red Bittersharp White Jersey Mild bittersweet
Backwell Red Sharp Broadleaf Jersey Med. bittersweet
Bramley’s Seedling Sharp (dual purpose) Cadbury Med. bittersweet
Brown’s Apple Sharp Fillbarrel Med. bittersweet
Cox Orange Pippin Sharp (dual purpose) Harry Master’s Jersey Med. bittersweet
Crimson King Sharp Michelin Med. bittersweet
Frederick Sharp Red Jersey Med. bittersweet
Gin Sharp Silver Cup Med. bittersweet
Langworthy Sharp Somerset Redstreak Med. bittersweet
Reinette D’Obry Sharp Stembridge Jersey Med. bittersweet
Royal Somerset Sharp (dual purpose) White Close Pippin Med. bittersweet
Tom Putt Sharp (dual purpose) Yarlington Mill Med. bittersweet
Yeovil Sour Sharp Ashton Bitter Full bittersweet
Court Royal Sweet Chisel Jersey Full bittersweet
Morgan Sweet Sweet Coat Jersey Full bittersweet
Northwood Sweet Dabinett Full bittersweet
Slack-ma-Girdle Sweet Major Full bittersweet
Sweet Alford Sweet Ellis Bitter Full bittersweet
Sweet Coppin Sweet Royal Jersey Full bittersweet
Woodbine Sweet Vilberie Full bittersweet

Source: Barker 1947; Williams 1987; Copas 2001.

caused by a virulent strain of Escherichia coli (0157:H7) have compli-

cated the production and marketing of fresh cider in the United States
(Riordan et al. 2001). The typically low pH range of cider does not
suppress this pathogen, which is now widespread and poses a potential
threat in fresh fruits and vegetable products as well as incorrectly
processed and prepared meats (Hilborn et al. 2000; Mazzota 2001).
Current Food and Drug Administration (FDA) regulations require phy-
tosanitary procedures, such as thermal pasteurization or ultraviolet
radiation to achieve a 5-log reduction of potential pathogens in fresh
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406 I. A. MERWIN, S. VALOIS, AND O. I. PADILLA-ZAKOUR

cider. In some states, cider-makers with approved risk-reduction or

hazard analysis critical control point (HACCP) plans are still permitted
to sell unpasteurized, unfermented ciders (Senkel et al. 1999), but the
trend is toward mandatory cider treatment with either heat or radiation
to inactivate potential pathogens, and it is difficult to obtain unpasteur-
ized cider for fermentation purposes in most regions. The new strain of
E. coli has been a less problematic issue for the European cider industry,
because alcoholic fermentation is known to be lethal to most potential
pathogens in cider (Semanchek and Golden 1996). Regulatory agencies
in the EU recognize this important distinction between fresh and fer-
mented ciders, and allow cider-makers to ferment juice made from
fallen fruit that have spent considerable time on the ground, after
minimal water-bath disinfestation of this fruit.
Following the widespread success of microbreweries and ‘‘brew-
pubs’’ that produce diverse styles of beers for regional markets,
there has been increased interest in regional ‘‘craft’’ cider-making in
the United States and Canada. There are now an estimated 100 small-
scale cider-makers around North America (B. Watson, personal com-
munication), yet there has been very little scientific research to support
this developing sector. Fermented cider is usually not considered as a
separate category in collecting statistics of production or market activity
in the United States, making it difficult to find reliable information on
hard cider or cider apples as a commodity sector.
Legal regulations and definitions of fermented cider are set nationally
by the FDA and the Alcohol and Tobacco Tax and Trade Bureau. Several
states have their own regulations as well (e.g., NYS-ABC Article 1, Sect.
3-7b). Most state and federal rules pertain to alcohol content—usually it
must be less than 7% (v/v) or it is considered an ‘‘apple wine’’ for tax
and regulatory purposes—and additions of distillate are usually not
permitted, or they are taxed at a higher rate than ‘‘hard cider.’’ Ironi-
cally, the lack of regulatory attention has actually posed problems for
U.S. cider-makers insofar as fermented cider remains in legal limbo
because it is neither wine nor beer—both of which have clear legal
definitions and regulatory processes.
There is no national organization dedicated to evaluating and improv-
ing the quality of U.S. ciders. Fortunately, there is an active Internet
listserve (The Cider Digest: cider@talisman.com) hosted in the United
States, through which European cider experts such as Andrew Lea have
generously provided advice to hundreds of participating amateur and
commercial cider-makers. Other than the traditional New England ciders
made from old Yankee cultivars such as ‘Northern Spy’, ‘Golden Russet’,
‘Baldwin’, and ‘Roxbury Russet’, there is essentially no definitive
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6. CIDER APPLES AND CIDER-MAKING TECHNIQUES 407

American cider style. Only a few domestic cultivars are grown or recom-
mended specifically for cider-making in North America, although several
popular-press publications provide recommendations on this topic
(Proulx and Nichols 1980; Correntry 1995; Watson 1999; Merwin 2005).
Several hundred of the English, French, and Spanish cider apple
cultivars, and some 3,000 other accessions of Malus
domestica and
other Malus species have been collected at the USDA-Plant Genetic
Resources Unit (PGRU) in Geneva, New York (Browning 1998; Forsline
et al. 2006). Descriptive profiles of these apples can be accessed online
in a database at www.ars-grin.gov/cgi, and budwood for most of them is
available for propagation by nurseries and interested fruit growers.
Unfortunately, the Geneva-PGRU collection of cider apples includes
several misidentified clones—including ‘Sweet Alford’, ‘Foxwhelp’,
‘Yarlington Mill’, and ‘Tremlett’s Bitter’. The last cultivar, whatever
its true identity, is an excellent Bittersharp that has performed very well
in some commercial New York plantings, and is being informally
referred to as ‘Geneva Tremletts’ until it can be positively identified
as another English cider cultivar or a serendipitous chance bud muta-
tion (P. Forsline, personal communication).
Despite the limitations just described, there is great potential for
ciders wherever apples can be grown in the United States, and also in
British Columbia, Ontario, and Nova Scotia in Canada. Thousands of
commercial growers produce hundreds of cultivars in these regions,
and many of these orchards are on or near established wine trails where
farm-based cideries could be a welcome diversification of the regional
agrotourist sector. There has been some cider apple research conducted
by Wilson et al. (2003) in Ontario, Canada, comparing common North
American apple cultivars with European Bittersweets for cider produc-
tion. Plantings have been established in the Finger Lakes region of New
York to determine the adaptability of French and English Bittersweets
and Bittersharps to the colder growing conditions in the Northeast
United States, and to date it appears likely that most of the European
cider cultivars can be successfully grown in North America (Valois et al.
2006; Valois 2007). However, some of these cultivars are prone to heat-
stress and ‘‘sunburn’’ damage in relatively hot growing regions with
continental-type climates (I. Merwin, unpubl.).
In northwest Washington State, Moulton et al. (2006) have estab-
lished research plantings of cider apple cultivars in the Puget Sound
region, which has a cool maritime climate similar to that of Brittany
and Asturias, and their reports on these cultivars’ performance are
available online (www.mtvernon.wsu.edu/frt_hort/ciderapples.htm).
Based on recent studies and communications with several commercial
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408 I. A. MERWIN, S. VALOIS, AND O. I. PADILLA-ZAKOUR

Table 6.5. Examples of apple cultivars available in North America and their suggested
proportions in a balanced cider blend. Many French and English Bittersweet and
Bittersharp apples are also available by special order from nurseries in North America
and can be grown for blending purposes where additional tannins are desired by the
cider-maker.

Fruit Blend
Recommended Cultivars Characteristics Category Proportion

Baldwin, Ben Davis, Braeburn, Fuji, Aromatic Sweets 60–80%

Gala, Golden Delicious, Gravenstein,
Jonagold, Mutsu, Tompkins County
King, Red Delicious, Rome Beauty, etc.
Chestnut crab, Golden Russet, Liberty, Soft tannins Mild 10–20%
Manchurian crab, Roxbury Russet, etc. aromatic bittersharps
Ashmead’s Kernal, Bramley’s Seedling, Acidity, Sharps 10–20%
Cortland, Cox’s Orange Pippin, Empire, aromatic
E. Spitzenburg, GoldRush, Granny Smith,
N.W. Greening, Idared, Jonathan, McIntosh,
Melrose, Newtown Pippin, Northern Spy,
NovaSpy, Winesap, Dolgo crab, etc.

cider-makers in the United States, a list of recommended domestic cider

apples from North America is presented in Table 6.5. Despite some
initial concerns about the late-blooming and late-ripening tendencies
of many European cultivars, and doubts about their winter hardiness in
the colder growing regions of North America, ongoing evaluations in
Washington and New York suggest that many of the English and French
Bittersweets and Bittersharps are adaptable to colder apple-growing
regions and can be successfully grown in North America. With renewed
research and grower attention to cider apples in North America, the
authors are hopeful that the next decade will provide more extensive
and quantitative information about the characteristics of domestic and
imported cider apples for American orchards, their nutritional and
cultural requirements, and the diverse styles of cider-making that could
support domestic cider industries of the stature and importance of those
in Europe.

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