Level 4 D1 Chap 17 - Wines with Residual Sugar Flashcards
What methods are there for concentrating grape must to produce wine with residual sugar?
- drying grapes on the vine
- drying grapes off the vine
- noble rot
- freezing grapes on the vine
How are grapes dried on the vine? Give examples
Stage 4 of ripening (extra-ripening) results in water loss by transpiration.
This results in extra-ripe flavours. e.g. Pinot Gris may develop tropical fruit and dried stone fruit flavours.
Long dry summers are required to avoid grey rot.
The stem may be broken to increase water loss. This is used in Jurançon in south west France.
How are wines made from grapes dried on the vine labelled?
Late harvest
Vendanges Tardives from Alsace
Spätlese from Germany or Austria.
How are grapes dried off the vine?
Grapes can be dried over days, up to months. (“Appassimento.”)
Warm counties may lay grapes out in the sun - southern Italy or Spain
Can also be dried in temperature and humidity controlled room.
Recioto di Valpolicella and Vin Santo in Italy are both examples of wine made this way
How are grapes concentrated through noble rot?
Botrytis cinerea (grey rot).
This must develop in a ripe grape, with damp mornings and dry/sunny afternoons.
The fungus leaves small holes in the skin that water evaporates through.
What types of wine are made from noble rot?
Sauternes
Beerenauslese
Trockenbeerenauslese
Tokaji
What is the impact of noble rot on sweet wine making?
As the rot is rarely uniform, several hand pickings are usually required.
Ideal weather conditions are unreliable and so the same vineyard may not produce botrytis every year
High doses of SO2 are required to minimise the impact of the fungal enzyme laccase.
Chilling and flushing with inert gases also help limit oxidation
Thick must is harder to press, clarify and ferment
How is ice wine produced?
Healthy grapes are left on the vine until frozen in winter and harvested whilst frozen (-8°C in Canada)
Pressing frozen grapes leaves ice crystals behind and the juice is more concentrated
Grapes will often go through several freeze/thaw cycles before harvest - thought to be important for icewine character.
Stainless steel is often used to retain aromas and flavours
Oak maturation is sometimes used
What are the protected terms for ice wine?
Eiswein in Germany and Austria
Icewine in Canada
What attributes are required for ice wine varietals? Give examples
Grapes need to be winter hardy and thick skinned.
Riesling and Vidal are common
What alternatives are there to traditional ice wine making?
Cryoextraction can replicate the effect of grapes freezing on the vine and is much cheaper, with lower risk of crop damage
How is sweet wine made by stopping fermentation early? give an example
Stopping fermentation early is more common with off-dry to medium sweet wines
The most common methods are chilling to 10°C, or a high dose of SO2. The wine is then racked and filtered
Used for inexpensive/ mid-priced wine. e.g. White Zinfandel
Fortified wine may use alcohol spirit to stop fermentation
How is sweet wine made by blending?
Blending in a sweetening component to dry wine reduces susceptibility to spoilage
There is a high degree of control
Suitable for inexpensive wines
RCGM or unfermented grape juice are most commonly added
Regulated in EU and in PDOs
