D5 – Fortified Wine
Practice Questions
(1) With reference to Sherry, define biological aging and describe conditions necessary for
this to take place. What effect does this have on the wine style?
Sherry that goes through biological ageing are typically Fino/Manzanilla.
Biological ageing involves development of flor yeast, and ageing under flor.
Conditions for biological aging
- At pressing, needs to be gentle and needs to use free run juice to minimize
phenolics (not to hinder flor growth)
- After fermentation and fortification (15% abv to 15.5% abv and no higher;
because do not want to kill the flor, which will lead to oxidation, rather
than biological ageing)
- Ageing place – old American oak vessels 600L, and into a Solera system
- Flor yeast (4 strains of Saccharomyces cerevisiae) to develop (environment –
Bodegas, cool and humid = temperature 16–20°C, 65% + humidity; and
thick walls, damp earthy floor to keep moisture, windows to take
advantage of the Poniente wind from the Atlantic to cool the Bodegas)
- Flor also needs plentiful oxygen; therefore, Sherry butts are left 85–90 per cent full and
the bungs are loosely inserted to ensure the flor is in contact with oxygen in the
headspace of the barrel.
- The solera system is stacked for different age wines (from Sobretabla to 1-3 Criadera to
Solera) and biologically aged wines has another function: the young wine from the
sobretablas is rich in nutrients for the flor, such as alcohol, glycerol and acetic acid. As
the wine matures under flor, these compounds are used up. The blending of younger
wines into older wines therefore helps to refresh the nutrient levels in older wines,
keeping a thick layer of flor alive, which continues to protect the wine from oxidation.
Effect on style <= dry tasting note (sweetness, acidity, alcohol, body, flavours,
colour, length & intensity)>
The layer of flor has a number of influences on the wine.
- it protects the wine from oxidation, and hence these wines remain pale lemon in colour.
- the flor consumes alcohol in the wine and releases acetaldehyde, which gives aromas
that can be described as apple (often apple skin or bruised apple), hay and/or
chamomile and sometimes a slightly bitter taste. And therefore low alcohol.
- it also consumes glycerol, which gives the matured wine a lighter body. Glycerol also has
a slightly sweet taste, and the reduction in glycerol can contribute to the very dry nature
of biologically aged Sherries.
- Flor also reduces the levels of acetic acid. (therefore low acidity)
These wines will not improve with bottle ageing and is designed to be consumed as fresh as
possible.
En Rama
- Some biologically aged wine will only be lightly filtered or not filtered, to add complexity
and character.
Passada
- Some biologically aged wine (Fino Viejo / Manzanilla Passada) with a minimum average
age of seven years. The flor may be left to die naturally by not refreshing the barrels with
new wine for around a year for some gentle oxidation. The wines may then enter a
solera system for Fino Viejo or Manzanilla Pasada, to give it some oxidized character
(nuttiness)
(2) Explain the roles of the following businesses in the Sherry industry.
The Sherry industry is made up of 47% Cooperatives that own vineyards, 31% of shippers and 22%
of independent growers.
Bodegas de la Zona de Producción (Production bodegas) These bodegas, which are usually
large co-operatives, press grapes and ferment the must into base wine. They are often owned
by a company within one of the other registers, but can be independent and will sell the base
wine to either of the ageing bodegas. They may sell their own wines, but these cannot qualify
for DO Jerez-Xérès-Sherry or DO Manzanilla – Sanlúcar de Barrameda.
Bodegas de Crianza y Almacenado (Ageing and storage bodegas) These bodegas, also called
almacenistas, mature wines. They tend to be relatively small in the amount of wine they
mature. The wines must then be sold to Bodegas de Crianza y Expedición.
Bodegas de Crianza y Expedición (Ageing and shipping bodegas) These bodegas, also called
‘shippers’, are the only ones permitted to export or sell DO JerezXérès-Sherry or DO Manzanilla
– Sanlúcar de Barrameda wines to the market. As well as selling the final wine, they are also
permitted to mature the wines, which may come as young wines straight from the Bodegas de
Producción or may come as matured wines from the Bodegas de Crianza y Almacenado. The
wines from the almacenistas may be blended with the shipper’s own stocks of wines to make up
volumes and add complexity. The wines are then generally sold under the shipper’s own brands;
however, the shipper Lustau has long had an almacenista range that, although branded by
Lustau, features wines by individual almacenistas and includes their name on the wine label.
Almacenistas, in particular, have suffered from the declines in Sherry sales. As demand reduced,
the shippers survived using their own stocks, not needing extra wine from the almacenistas, and
consequently many almacenistas went out of business. In 1996, the Consejo Regulador lowered
the minimum stockholding for companies to register as a shipper from 12,500 hL to 500 hL. This
meant that a number of the biggest almacenistas, such as El Maestro Sierra and Bodegas
Tradición, became shippers and therefore now market their own wines under their own brands.
(3) Discuss the maturation of Port in bottle.
The examiners report highlighted the following points: which styles benefit, differences in
acids, phenolics, flavors when bottled vs cask aging, how structure evolves, how bottling
and ageing differs for styles.
Identify which Port is suitable for bottle ageing:
- Ruby Port (Vintage, Crusted, LBV, Quinta)
Identify which Port is NOT suitable for bottle ageing:
- Tawny – Not suitable for bottle ageing – already fully developed
- White (oxidized white port) – Not suitable for bottle ageing
- Youthful style Port = Basic Ruby = Fruit will fade, therefore deteriorate
For Ruby Port (Vintage, Crusted, LBV, Quinta), as it is suitable for bottle ageing, it will lead to
development of desirable Tertiary characters:
- rancio (leather, chocolate,) dried fruit (fig, prune, raisins), cooked fruit (plum, cherry) ,
tobacco, wet leaves, forest floor, caramel, mushroom, earth, meat, nuttiness.
Why?
This is because:
- Grape variety (e.g. Touriga Nacional) – thick skinned grape; therefore high level of
anthrocynanin and tannin, which is a key component to allow bottle ageing due to its high
ageing potential. In particular, Vintage port uses the best quality grapes from best harvest,
offering excellent ageing potential.
- Level of tannin: it tends to have greater extraction of tannin due to the lagare method (foot-
treading/ piston plungers) as opposed to autovinifiers for Tawny or more basic port.
Therefore, with greater and sufficient tannin levels, these Ruby style ports are more well
suited to bottle ageing.
- Polymerisation: due to small amount of oxidation in bottle, tannin will polymerise and as a
result soften, and lowers astringency, also leading to development of more complex
characters.
- Maturation in bottle: due to strong concentration of fruit, this is essential element to lead to
tertiary flavours (dried fruits), especially high quality grapes are used for these styles of Port.
- Acidity: high acidity a key component to successful bottle ageing, and it will mellow over
time, giving better mouthfeel.
- Storage condition: this will dictate whether desirable tertiary flavour development will
happen
However, for Tawny and Oxidised White Port, they are already fully developed during cask ageing
with oxidized characters. Therefore, they will hold but not improve.
In addition for unaged basic styles of Port (i.e. Basic Ruby), it has not got the acidity, nor fruit
concentration nor tannin to allow bottle ageing. If left to bottle age, it will only lead to fading of
primary fruit flavours and deteriorate.
Bottle ageing:
- High acidity
- High tannin
- High fruit concentration
- High alcohol
- Sweetness (residual sugar)
(4) Discuss the role of climate and topography in Port production(winemaking + grape
growing)
Grape Growing
Climate:
- Warm Continental, temperature easily to 40 degrees in summer, and freezing temperatures
in winter
Topography:
- Serra do Marao – shelter sites from Atlantic Ocean wind, resulting in vineyard areas being
much warmer and drier.
3 main areas of Port Grape growing:
- Baixa Corgo
o High rainfall 900mm
o Coolest and wettest, as it is closest to the Atlantic, therefore produces inexpensive
grapes for inexpensive Ruby and Tawny styles
o e.g. producers will tend to use cordon trained VSP vine system to help vines to have
more air circulation, sunglight interception, to avoid risk of fungal disease (downy
mildew and botrytis)
- Cima Corgo
o Drier rainfall 700mm
o Warmer and drier, so produces age indicated Tawny and Vintage
- Douro Superior
o Driest 450mm rainfall
o Hottest and driest with flat areas, therefore sparsely planted to avoid fruit flavour
dilution
o Susceptible to drought, causing vine stress. So producers have to employ drought
resistant rootstocks. (110R Hybrids of V. Rupestris and V.Berlandieri)
o Flat areas facilitates mechanization (i.e. harvest by machine)
Overall, the area is divided by the Douro River that offers moderating influences and (i.e. cooling
influences to sites near the river, carrying cooler/warmer winds along the river) and a range of
microclimates. It also varies given the area is composed of land of varying altitudes, and aspects,
(steep slopes with over 30% gradients), leading to different sunlight exposure and average
temperatures.
In addition, on high altitude sites (Baixa Corgo), it is more susceptible to spring frosts. And can use
sprinkler irrigation to avoid spring frosts.
This in turn affects growth and ripening of fruits/sugar accumulation, and acidity.
Wine making (maturation)
- Maturation – Villa Nova de Gaia (in Porto); it has climate more suited to maturing port. This is
because it holds generally cooler and more constant temperatures due to influence from the
Atlantic Ocean.
- But more recently, due to the area being overwhelmed by tourist activities, many producers
have now established modern maturing facilities with well-insulated humidity control, onsite
next to the vineyards. This takes out the risk given by fluctuating climates.
(5) Compare and contrast the fermentation and fortification processes for red VDN and Port.
Fermentation
Port – Extraction first by foot treading/pistons/Modern lagares/ Pumping over/Autovinfier; then
fermentation.
Modern fermentation vessels (including those used in modern lagares) tend to be made from
stainless steel. This allows for easy temperature control and means that if necessary, the tank
can be cooled to slow the fermentation and therefore prolong the period of extraction. Stainless
steel also has the advantage of being easy to clean. Some producers use granite, concrete or old
wooden vessels, usually for small-volume wines. The grapes may or may not be destemmed.
Unripe stems can impart bitterness, however, if stems are fully ripe they can aid pressing
(reducing compaction of the pomace and enabling better drainage) after the fermentation has
been stopped and free run wine drained. Fermentation temperatures for red wines tend to be
28–32°C (82–90°F), warm enough to allow sufficient extraction but not so warm that the
fermentation progresses too quickly and reduces the available extraction time before pressing
and fortification.
VDN - is typical for the must to be fermented and fortified while in contact with the grape skins.
For red wines, stainless steel vessels are used for fermentation to allow for easy temperature
control. Red wines tend to be fermented at around 28°C (82°F) to promote extraction but retain
fruity aromas.
The addition of the fortifying alcohol increases the extraction of colour, flavour and tannins, all
of which are important for wines that are to undergo extensive ageing. Maceration on the skins
can continue for a couple of weeks past the fortification date to maximise extraction.
Likewise, VDN uses Cap management techniques such as pumping over and punching down are
also used to maximise extraction.
Fortification:
Port = 77% abv Aguardente, to give a “spirity” flavour, (i.e. every 1 L spirit for every 4 L of must),
hence needs more volume of spirit to fortify
Fermentation is stopped by fortification when abv reaches 5-7% abv
VDN = 96% abv neutral spirit to preserve primary fruit characters, when spirit reaches 5-8% abv, in
order to make final wine of 15-18% abv. Hence only used 10-15% of the wine is made up of spirts,
which is less than the amount of spirits used for Port (1L:4L)
Port
In Port production, fermentation is stopped by the addition of grape spirit to create a sweet
wine (usually 80–120 g/L residual sugar). The maceration with the skins lasts for a maximum of
two days and therefore extraction techniques need to be very effective. The key methods of
extraction during the fermentation include:
Foot treading in lagares Lagares (singular lagar) are shallow (around 80 cm deep) square tanks,
allowing a large surface area between the must and grape skins. Traditionally, they were made
from granite and the extraction would come from foot treading. Foot treading is effective at
extracting but at the same time gentle enough not to crush the seeds, which would release
bitter tannins. This is still the method used for a small number of premium and super-premium
Ports.
Modern lagares Also called robotic lagares. More recently, modern lagares have been created in
which silicon ‘feet’, attached to a stainless steel gantry, press the grapes against the lagar floor
and subsequently punch down the cap. The advantage of modern lagares is that they reduce
the need for a large hired workforce, which can be difficult to obtain and unreliable. However,
the initial investment for this equipment is higher. Modern lagares can produce wines of equal
quality to those that are produced by foot treading, although some producers continue to use
foot treading for their most expensive wines.
Pumping over This technique is the same as that used for non-fortified wines. Although this
technique can produce Ports with deep colour and high levels of concentration through
frequent pumping over, it is not as effective at extracting as foot treading or modern lagares.
Stainless steel pistons This technique uses open stainless steel vats with pistons that punch
down the cap to a programmed schedule. This can be used in conjunction with pumping over,
which is usually needed to promote a more-even extraction. This technique is believed to be
almost as effective at extracting as lagares and seems to produce wines that are very similar in
quality to those that have been made by foot treading in lagares.
Autovinifiers These sealed concrete or stainless steel tanks provide a solution to cap
management that does not require electricity. The rising pressure of the CO2 produced from the
fermentation pushes the juice up through pipes into a holding tank. When the pressure of the
CO2 reaches a certain level, a valve is automatically released and the wine in the holding tank,
no longer supported by the gas pressure, sprays over the cap. The key advantage of this
technique is that it does not require electricity and therefore can be one of the cheapest
options. However, because the process is reliant on CO2 released from fermentation, very little
extraction occurs before the fermentation starts. This means that the wines that this technique
tends to produce are lighter in colour, body and flavour, suitable for basic Tawny, White and
Ruby Ports.
Modern fermentation vessels (including those used in modern lagares) tend to be made from
stainless steel. This allows for easy temperature control and means that if necessary, the tank
can be cooled to slow the fermentation and therefore prolong the period of extraction. Stainless
steel also has the advantage of being easy to clean. Some producers use granite, concrete or old
wooden vessels, usually for small-volume wines. The grapes may or may not be destemmed.
Unripe stems can impart bitterness, however, if stems are fully ripe they can aid pressing
(reducing compaction of the pomace and enabling better drainage) after the fermentation has
been stopped and free run wine drained. Fermentation temperatures for red wines tend to be
28–32°C (82–90°F), warm enough to allow sufficient extraction but not so warm that the
fermentation progresses too quickly and reduces the available extraction time before pressing
and fortification. Fermentation temperatures for whites range from around 17–22°C (63–72°F),
for further details see White Port. Many producers use ambient yeasts for fermentation as
these are sufficient to start the ferment (and completing fermentation to dryness is not a
concern for Port production).
VDN
For VDNs made from black grape varieties, it is typical for the must to be fermented and
fortified while in contact with the grape skins. The addition of the fortifying alcohol increases
the extraction of colour, flavour and tannins, all of which are important for wines that are to
undergo extensive ageing. Maceration on the skins can continue for a couple of weeks past the
fortification date to maximise extraction. Cap management techniques such as pumping over
and punching down are also used to maximise extraction.
For both red and white wines, stainless steel vessels are used for fermentation to allow for easy
temperature control. White wines tend to be fermented cool at around 15°C (59°F) to enhance
the production of fruity ester aromas. Red wines tend to be fermented at around 28°C (82°F) to
promote extraction but retain fruity aromas
(6) With reference to Port wine, discuss the responsibilities of the IVDP and the role of the
Beneficio?
Responsibilities of the IVDP
IVDP = a professional body formed in 2003, controls and and supervises the production and trade of
wines in Douro (both unfortified and Port)
It also:
- Regulates the amount of port that can be produced every year (the Beneficio)
- Holds the register of vineyards and companies that produce and ship
- Control volume of Port that can be released onto the market every year (i.e. set at maximum
of 1/3 of a shipper’s total)
- Analyses and tastes port wines to ensure specs are met to defined Port styles
- Promotes Port and unfortified wine from Douro
Role of the Beneficio
= controls the amount of Prot must produced each year
The system also:
- Classifies each vineyard parcel by grading them to A to I, thereby assessing factors such as
location, altitude, aspect, soil and grape varieties to give such a rating.
- Only A to F grade vineyards can grow and supply grapes for Port production. Below F
grades cannot be used for Port making (i.e. unfortified wine only)
- The IVDP also facilitates agreement between growers and producers on the amount of must
that can be produced each year. The purpose of this is to ensure grape and wine prices are
stable, by balancing supply with demand.
- With the vineyard rating, each producer is given a card/certificate for each parcel of land they
own.
- The system sets the price for grapes used for Port, at relatively higher price (1.2-1.4 euros).
Which is intended to protect the interests of the Port grape growers
- However it is a subject of controversy, particularly because demand for Port has been on the
decline for the few decades by half. This does not benefit the marginal player of Port grape
growing. As a result, the larger players buy up their land to increase production of Port for
their own benefits, and also in turn those with lower rated sites are being subsidized for their
survival.
(7) Compare Canteiro and Estufagem processes and explain how each affects style, quality
and price of Madeira.
Similarities and Differences
Estufagem and Canteiro are 2 different maturation methods for Madeira.
Estufagem involves heating of wine in Temperature controlled Stainless steel tank (Estufas) via
heating jacket or coil. It is heated up to to 45-50 degrees Celsius to accelerate ageing; whereas
Canteiro is a method that keeps wine must in old oak vessels (typically 600-700L barrels) in a loft or
warehouse, at relatively 25-40 degrees celsius caused by the sun.
Once heated Estufagem wil be kept in the stainless steel tank for minimum of 3 months, usually 6-12
months to allow cooling; whereas Conteiro will be kept in barrels for at least 3 years after 1 January
after harvest.
When ageing, both Estufagem and Canteiro will have their vessels sealed and unsealed by a
representative from IVBAM.
Canteiro can involve an even longer ageing period, by another 5 years, subsidized by the EU. Again
it will be sealed and unsealed by IVBAM. Further ageing can take place in larger wooden vessels,
stainless steel or demijohns.
Styles:
Both methods due to oxidation will lead to wines turning into Brown colour, development of baked or
stewed tertiary flavours (dried fruits), caramelization of sugar and often with smoky characters.
However, Estufagem tends to be used to produce younger inexpensive styles of wine (Tinta Negra),
because shorter time and less resources used, process speeded up by the heat applied by heating
jacket/coils in Estufas. Hence, it develops less complex wine than Canteiro.
- Whereas Canteiro is for more high quality premium wine (recommended grapes – Sercial
etc) , due to the resources (old oak barrels, storage space) and more time involved.
- Due to warm temperatures and evaporation, it will lead to concentration in flavours and
increase in alcohol to around 19-20% abv. Also, volatile acidity will develop
Estufagem
- Temperature controlled Stainless steel tank (Estufas) – heating jacket or coil
- Heat up the wine to accelerate ageing (oxidation) to 45-50 degrees Celsius
- Wine must to remain in tank for 3 months minimum
- Tank not usually filled to the top, ullage to allow some oxidation.
- Then tank is sealed by IVBAM
- Allowed to cool and stored for 6-12 months
- And cannot be sold until 31 Oct of 2nd year
Style: the process will lead to Baked or stewed characters, but not in same complexity as the slower
Canteiro process.
Canteiro
- Longer and resource intensive process
- Wines will be stored in old oak vessels (400-700L barrel) in warm environment, (loft or
warehouse). Ullage left to allow oxidation.
- It will be heated by the sun and will reach temperatures of 22-40 degrees Celsius.
- Producer can keep wine in different areas of the warehouse (i.e. in cool vs warm parts)
- He may keep young wines in the warmest areas to speed up maturation, and older wines in
warmer locations.
- Similarly, IVBAM will seal and unseal the vessels.
- And wine cannot be sold until after 3 years after 1 January after harvest.
Style:
- Due to warm temperatures and evaporation, it will lead to concentration in flavours and
increase in alcohol to around 19-20% abv.
- Volatile acidity will develop
(8) With reference to fortified wines, discuss the use of Muscat.
Answer structure:
- Identify wine type
- Identify Talk about grape varieties
- Identify wine style (ox vs un-ox) => the flavour and character profile
Muscat is used to make the following types of fortified wine:
- Naturally Sweet Sherry = Muscatel of Alexandra
o Less common wine
o Style of wine:
Oxidative aged: (RS typically 325-375g/L)
Raisining in the sun
Ferment to 4-6% abv
Fortify 15-16% abv
Matured oxidatively in Solera system - evaporation
concentrating sugars and flavours
Unaged non-oxidative wine = RS 160g/L
(typically 325-375g/L)
Dried fruit (raisins)
- White Port = Muscatel - Muscat Blanc a Petits Grain
o Muscatel tends to be one of the key grape varieties in the blend for unoxidized
aromatic floral grapey young wine.
- Rutherglen Muscat = Australian Brown Muscat – Muscat a Petit Rouge
Late hang on the vine until extra ripe and shrivel (No Botrytis
to avoid undesirable Orang Marmalade)
To accumulate sugar to help reach potential alcohol of 20%
abv
Dried fruit (raisin)
Style of wine:
Oxidized wine:
o Kept in warm tin roofed storage
o Freshness depending on frequency of top up
(Australian Solera system)
- VDN (RS = 100-125g/L)
o Muscat Blanc a Petits Grain
Smaller grapes; therefore more flavour intensity of fruity,
floral and grapey characters
o Muscat of Alexandra
Bigger grapes: therefore less intensity
o Style of wine:
Unaged non-oxidised wine:
Protective win making to retain primary fruit (floral,
grapey, peach, pear and honey)
Aged Oxidised wine:
Old oak barrels with ullage and no top up to oxidise
Bonbonnes (demijohns unstopped, not full, left outside
in the sun) to speed up ageing process
