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6. CIDER APPLES AND CIDER-MAKING TECHNIQUES 1

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 © 2008 John Wiley & Sons, Inc.

365
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

1. INTRODUCTION

In western Europe and North America, there is an old tradition of apple (Malus x 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 priorities in cider production. The related
tradition of pear (Pyrus communis L.) production for perries (fermented pear juice) will also be considered
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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
publications in each of these areas, our review will of necessity be selective. For more comprehensive
reviews specifically on fermented cider, readers 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 Mediterranean 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 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. x domestica types of
that era (Bore 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, resulting 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. x domestica and that M. sieversii is their dominant ancestor. However, 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 sanitation 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 knowledge 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 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 indigenous 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
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6. CIDER APPLES AND CIDER-MAKING TECHNIQUES 3

concentrations in the juice. Barrels in which oxygen enters to ‘‘spoil’’ the cider are usually converted
naturally to cider vinegar by indigenous ^actic acid bacteria (Lactobacillus, Leuco- nostoc, Pediococcus
sp.), and the resultant vinegar was a historically important preservative that could be used for pickling and
other culinary 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 probably 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).
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 conservative, 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.
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
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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
astringent (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 categories 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)

In France and Spain, an intermediate category, ‘‘acidule'e’’ or ‘‘acid- ulada,’’ (respectively) is

sometimes used for semitart cider cultivars with low tannin content (Bore 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 singlecultivar 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 fermentation to the desired final ethanol content, usually 3 to
7% (volume/ volume). In practice, cider-makers in Europe typically utilize a mixture 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 remaining 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 fermented ciders therefore includes tart, aromatic, neutral/base, and tannic
cultivars.
There is no systematic classification of North American apple cultivars 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 recommended 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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6. CIDER APPLES AND CIDER-MAKING TECHNIQUES 5

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 subunits. The perceived flavor or ‘‘mouth-feel’’ of apple
phenolic compounds is more bitter and harsh when the predominant procyanidins are oligomeric (2 to 4
phenolic subunits). These short-chain polyphenolics 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 molecules, 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
content have been determined for hundreds of apple cultivars (Williams 1987; Fuertes et al. 1996; Bore
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 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 western 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 cultivar 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 phenolic 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 acidity
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), Switzerland (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 fermentation, 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 bottling (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
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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).
374

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’’ ofa dozen or so layers that is pressed slowly under increasing
pressures to obtain the juice. The rack-and-frame press is more laborintensive 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 traditional lagar press is not efficient, but it produces a characteristic
highly colored, low-tannin cider with substantial volatile acidity that is popular 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

Fig. 6.1. A traditional Spanish oak lager screw press in operation. Pressing can take several days, allowing partial mash fermentation,
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6. CIDER APPLES AND CIDER-MAKING TECHNIQUES 7

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
production 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

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 ofN 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 winemaking, 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-
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makers and winemakers generally add a complete yeast nutrient blend (supplement), which contains the B
vitamins as well as a nitrogen source such as 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 conditions, 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 finished 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
different 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
378

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 winemaking 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 compared 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 berryA 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 compounds 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
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6. CIDER APPLES AND CIDER-MAKING TECHNIQUES 9

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 cidermakers often take advantage of this process with a
technique known as mace'ration 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 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 expensive way to increase
the phenolic content of the cider is to add grape tannins, because powdered apple tannins are not
commercially available. 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) evaluated different types of tannin addition in ciders and reported that
organoleptic panelists could distinguish readily and had clear preferences 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 fermentation 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 carbonation can be added in the storage tank by injecting carbon dioxide (CO 2) or to each
bottle immediately before capping. In order to have a stable product for extended shelf life, cider with
residual sugars must be heat-treated, or sulfur dioxide (SO 2) and preservatives such as potassium 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 solubility 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. Pasteurization units (PU) are used to define the necessary time-by-
temperature interactions in this process, based on the equation PU = t x io(T-6OC)/z, where t is time in minutes,
T is temperature in 8C, and z is 78C. Cider needs approximately 5O PUs, heated for 5O minutes at 6O8C
or an equivalent time and temperature combination, for a stable product and complete suppression of
potential spoilage microorganisms (Duffy and Shaffner 2OO1). The resultant cider will not be completely
sterilized; thus it is necessary to have a low initial microbial load (Mitchell 2OO6). 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.
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I. A. MERWIN, S. VALOIS, AND O. I. PADILLA-ZAKOUR

A recently developed alternative to sulfites and pasteurization is the use of a processing aid and cold
sterilant—dimethyl dicarbonate (DMDC, trade name Velcorin )—which can prevent fermentation and
1

reduce spoilage microorganisms in juice and wine (Threfall and Morris 2OO2; Williams et al. 2OO5). This
treatment is approved for juices and wines at 25O parts per million (ppm) but not yet approved for cider
due to lack of demand from the cider industry. DMDC hydrolyzes immediately into minuscule amounts of
methanol and carbon dioxide after introduction into the product without affecting its taste, odor, or color
(Lanxess 2OO5). 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 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 carbonate, or addition of artificial (usually nonfermentable) or natural sweeteners 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 SO 2 required as the juice pH increases (Beech 1972). Sulfur
dioxide acts as a preventive antimicrobial agent before fermentation begins. It inhibits wild yeast growth
and allows for the pitched Sacharromyces strains (which are more resistant to SO 2 than wild yeasts and
most of the potential spoilage microorganisms) to develop and dominate the fermentation (Jarvis and Lea
2000). In addition to its antimicrobial effects, SO 2 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 oen) 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
382

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 proportional 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
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6. CIDER APPLES AND CIDER-MAKING TECHNIQUES 11

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 thresholds (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). Polyphenolic 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 suggested 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 internal 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 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 constituents of many foods and beverages,
and have been shown to possess anticarcinogenic, anti-inflammatory, and antioxidant capacities (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 published 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 ascorbic 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 epicatechin). 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 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
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I. A. MERWIN, S. VALOIS, AND O. I. PADILLA-ZAKOUR

color, which may be lessened during fermentation and with addition of sulfites.
Polyphenols are metabolized in fruit by enzymatic pathways regulated 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 regulators 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 substantially 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
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 constituents 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.

II. Cider Appearance. Visual aspects of cider can also influence consumer 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).

ORCHARD SYSTEMS FOR CIDER APPLES

A. Modern versus Traditional Cider and Perry Orchards

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6. CIDER APPLES AND CIDER-MAKING TECHNIQUES 13

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 plantings (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.
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 traditional 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 organization
of regional appellations for cider and farm-cider trails have encouraged 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 consistent 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 sizecontrolling 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 comparable dessert apple orchards (Umpelby
and Copas 2002). Management strategies are designed to maintain tree health and productivity, but are
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I. A. MERWIN, S. VALOIS, AND O. I. PADILLA-ZAKOUR

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 management. 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 far apart in pastures on small hillside farms (Sanchez et al. 1991). With the renaissance of
provincial cultural traditions and increased independence 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 treatments (Williams 1987; Fuertes et al. 1997; Merwin, 1999). These
differences 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 advantageous 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; Bore 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 cultivars that bloom
along with standards like ‘Golden Delicious’ or ‘Gala,’ while flowering of others is delayed a month or
more (Morgan and Richards 1993; Bore 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 the appropriate time for each cultivar. Williams (1987) suggested
grouping 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 applications 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 substantial year-to-year variation in production from some of the traditional
cultivars. However, the list of recommended cultivars for modern plantings in Europe does reflect biennial-
bearing tendencies, and growers are encouraged to plant the more annual-bearing cultivars when feasible
(Williams 1987; Bore 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
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6. CIDER APPLES AND CIDER-MAKING TECHNIQUES 15

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 polyphenolic 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 treatments. 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, 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 N -ha 1 -yr 1), 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 ha 1 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 applications (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; Bore and Fleckinger 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 24 o 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 production, 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 traditional fermented drink.

III. NATIONAL AND REGIONAL CIDER CULTURES AND CULTIVARS

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

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 bouche' (literally, ‘‘corked ciders’’) consumed in trendy French restaurants 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

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 17

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 originated 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; Bore 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 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 (Bore and Fleckinger 1997). About 70 elite cultivars are now recommended for cider production
in France (Table 6.2), differentiated by region based on their high juice yields, tree productivity 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 bouche' is produced by regional artisans from traditional cultivars of each region, and usu-
ally is bottle-conditioned with some residual sugars and natural effervescence. Many artisanal cider-makers
market their products under appellation d’origine controle'e (AOC) labels, following rules that prohibit
chaptalization (additions of refined sugar to the fermentation), the 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’ (Bore and Fleckinger
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I. A. MERWIN, S. VALOIS, AND O. I. PADILLA-ZAKOUR

1997). Recent statistics for French cider production (Info-Cidre.com) indicate that national consumption is
about 110 million 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 cidermakers in regional
agrotourism, 10 large-scale industrial producers account for 85% of the cider made in France at present.

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
Limon Montes 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
Duron 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.
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
regulations 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 biological 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
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 CO 2 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
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6. CIDER APPLES AND CIDER-MAKING TECHNIQUES 19

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). However, keeving is customary in artisanal cider-making,
and when successful it can produce naturally sweet and effervescent ciders with enhanced fruity volatiles.
French cidre bouche' 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 distilled 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 produced 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 fermenting 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 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 important 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 Sees in Lower Normandy. The National Institute of Agricultural Research
(INRA) maintains a comprehensive germplasm collection and pursues descriptive 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 characteristics, precocity,
and productivity (Bore 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 production, although the genetic resistance of ‘Judeline’ and
some other cultivars to Venturia inaequalis has failed as the pathogen developed resistant races able to
overcome some of the naturally occurring applescab resistance genes in Malus sp.
B. Spain
Traditional cider apples are grown primarily along the north coast of Spain, in the cool maritime climate
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I. A. MERWIN, S. VALOIS, AND O. I. PADILLA-ZAKOUR

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. x 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 tourists 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 producers 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 centuries. 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.

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
Category Category
Cultivar Cultivar
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 Vitro Sharp
Avalou Belein Bittersweet Jeanne Renard Bittersweet
Belle Fille de la Manche Bittersweet Joly Rouge Bittersweet
Bergerie de Villerville Bittersweet Judin Sharp
Binet Blanc-Dore 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 Rene Martin Sharp
Douce Bloc Hic Sweet Rouge de Treves Sharp
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6. CIDER APPLES AND CIDER-MAKING TECHNIQUES 21

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
Egyptia Bittersweet Saint Martin Bittersweet
Fil Juane Sharp Sorte Petite de Parc Dufour Sweet
Grise Dieppois Bittersweet Taureau Bittersweet
Groin D’Ane Bittersweet Teint Frais Bittersharp
Gros Bois de Bayeux Bittersweet Tesnieres Sharp
Guillevic Sharp Tete de Brebis Bittersweet
Source: Primault 1993; Bore and Fleckinger 1997; CTPC Web site at http://ctpc.cidre.net.400
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
skillfully (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 definitions and controls over cider-making.
Basically, these regulations require growing certain characteristic cultivars in each province, harvesting
and handling the fruit in certain ways, and limiting additives or processing of the finished ciders. In
Asturias, two strictly defined 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.
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I. A. MERWIN, S. VALOIS, AND O. I. PADILLA-ZAKOUR

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.
402

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
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6. CIDER APPLES AND CIDER-MAKING TECHNIQUES 23

heyday of English 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

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 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, indirectly benefiting cider-makers worldwide until it
was eviscerated during 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 southwest 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.
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I. A. MERWIN, S. VALOIS, AND O. I. PADILLA-ZAKOUR

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
according to the most basic criteria of the AICV, as fermented apple (or pear) juice or blends including
juice concentrate, with an alcohol concentration between 1.2 and 8.5% (v/v), without added distilled
spirits, colorants, or flavorants. A detailed list of permitted additives and ingredients in English ciders is
available in Mitchell’s (2006) NACM handbook.

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

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

Generally Generally
Recommended Recommended
Blending
Cultivars Cultivars
Blending Category 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 complicated 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 cider. In
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6. CIDER APPLES AND CIDER-MAKING TECHNIQUES 25

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 unpasteurized 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 fermented 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 ‘‘brewpubs’’ 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 smallscale cider-makers around North America (B.
Watson, personal communication), 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 improving 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 American cider style. Only a few domestic cultivars are grown or
recommended 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 x 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 mutation (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
heatstress and ‘‘sunburn’’ damage in relatively hot growing regions with continental-type climates (I.
Merwin, unpubl.).
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I. A. MERWIN, S. VALOIS, AND O. I. PADILLA-ZAKOUR

In northwest Washington State, Moulton et al. (2006) have established 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 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 domesticAcider industries of the stature and importance of those in Europe.

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
Characteristics Category
Recommended Cultivars Proportion
Baldwin, Ben Davis, Braeburn, Fuji, Gala, Golden Aromatic Sweets 60-80%
Delicious, Gravenstein, Jonagold, Mutsu,
Tompkins County King, Red Delicious, Rome
Beauty, etcA
Chestnut crab, Golden Russet, Liberty, Manchurian Soft tannins Mild 10-20%
crab, Roxbury Russet, etc. aromatic bittersharpsA
Ashmead’s Kernal, Bramley’s Seedling, Cortland, Acidity, aromatic Sharps 10-20%
Cox’s Orange Pippin, Empire, E. Spitzenburg,
GoldRush, Granny Smith, N.W. Greening, Idared,
Jonathan, McIntosh, Melrose, Newtown Pippin,
Northern Spy, NovaSpy, Winesap, Dolgo crab, etc.

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