Ch 17 RS Winemaking Options Flashcards
RS Winemaking Options
In general, what are the 3 main ways of making wines w/RS?
- Concentrate sugar in grape must - drying grapes on or off vine
- Stop Fermentation (chilling)
- Blend in sweetener
RS Winemaking Options
What are the three main ways sugars are concentrated in grape must?
Dry grapes on or off vine
Noble rot
Freezing on vine
RS Winemaking Options
What are the 3 main factors winemakers need to consider?
- Desired QSP
- Climate of vineyard site
- Local laws
RS Winemaking Options
What is the objective for winemakers making wines w/ RS?
Make a wine with balanced RS and acidity and flavor concentration appropriate for sweetness level
RS Winemaking Options
What styles are made by concentrating sugar in grape must?
Sweet and luscious
RS Winemaking Options
What are 2 general ways sugar is concentrated in grape must?
Why and what are considerations?
- Fermentation stops naturally -> yeast struggle in very sugary environ esp when alc also present -> naturally stop ferm even at low alc levels
- winemaker stops ferm -> chilling or adding SO2, then filtering out yeast = winemaker has more control over balance of alc and sweetness
RS Winemaking Options
Overall, how does concentration of grape must work and what happens in the process?
What quality levels use this?
○ Must is concentrated by reduction of water in the grape -> concentrates not only sugar but also other components like acid and flavors
○ Increased acidity keeps sweetness in balance -> why many of these wines are very good or outstanding quality
○ Method of removing water from grape can also add its own flavors -> ex dry on vine adds dried fruit = more complexity that wines made by simply stopping ferm, chilling or adding sweetener
RS Winemaking Options
What are implications/considerations for winemaking of concentrating must?
○ Removing water from grapes means volume of juice is low
○ Sugary pulp can be hard to extract during pressing
○ Inc costs -> often premium or super prem
RS Winemaking Options
How are grapes dried on the vine?
What happens to the grape and what environ condition is needed for this to happen?
Examples?
Labeling implications?
○ If grapes left on vine, they enter stage 4 of ripening process
○ Water is lost via grape transpiration -> concentrates sugars and flavors can continue to develop
○ Ex - PG may develop from stone fruit to tropical fruit and dry stone fruit
○ Dry autumn needed to avoid grey rot -> would give off flavors
○ Can be labelled as late harvest incl Vendages Tardives from Alsace and Spätlase from Germany/Austria
RS Winemaking Options
What is another method of drying grapes on the vine?
How is it done?
Why do it and what are considerations?
Example?
○ Cane of vine is cut a short time before harvest - usually stays on trellis
○ Grapes shrivel more quickly since not attached to vine -> concentrates sugars, acids and flavors
○ Reduced hangtime reduces - but doesn’t elim - grey rot risk
○ Allows getting grapes with very high sugar levels w/o extra ripe flavors - due to speed of concentration
○ Ex - sweet wines in Jurançon (SW France) and sometimes Australia
RS Winemaking Options
What is process for drying grapes off the vine?
What happens?
What conditions needed in warm vs cool climates?
Aka and examples?
○ Fully ripe grapes are picked and then dried
○ Drying process causes water to evap -> concentrates sugars, acids and flavors
○ Drying can last days to months - depends on amt of drying needed and speed of drying process
○ Warmer climate -> bunches can be laid out to dry in sun -> S Italy/Spain
○ Cooler climate -> bunches dried in temp and humidity controlled room -> speed up drying and avoid grey rot ex - Valpo
○ Climate controlled rooms more expensive
○ Aka - Appassimento method in Italy - Recioto di Valp and Vin Santo
RS Winemaking Options
What is noble rot and how does it relate to grey rot?
What conditions are needed for it?
what does it do to the grape?
What does it add to wine?
○ Botrytis cinerea fungus
○ Same as grey rot, but in proper conditions creates concentrated sugar and flavors in grapes
○ Grapes must be fully ripe before rot dev
○ Must be in region w/ misty/moist mornings and sunny/dry afternoons ->
○ damp mornings allows rot to dev -> punctures grape skin with microscopic filaments - leaving tiny holes in skin
○ Warm afternoon sun slows dev of rot and causes water to evap -> concentrates sugars, acids and flavors
○ Fungus also creates some aroma compounds and generates unique flavors -> honey, apricot, citrus zest, ginger, dried fruit
RS Winemaking Options
What QSP use noble rot?
Examples?
○ Prem/super prem sweet wines - sauternes, BA, TBA, Tokaji
○ Much more common on white grapes than black
○ Term botrytised often used on labels
RS Winemaking Options
What are viticultural implications of noble rot?
What happens in bad conditions?
○ Spread of noble rot never uniform -> can req several picking by hand to select best grapes
○ Expensive process - skilled labor and time
○ Volume of juice low -> selective picking and water has evap from grapes
○ Ideal conditions may not happen every year -> wines can be scarce/expensive
○ If wrong conditions (too damp) -> fungus grows too fast and grey rot forms -> split grapes and encouraging infections
RS Winemaking Options
What are challenges in winemaking for Bot grapes?
What options to address?
What winemaking options used?
enzyme
○ Fungus adds an enzyme - laccase - that can oxidize some components in grape must and wine and is relatively resistant to SO2
○ Chilling and high doses of SO2 and use of inert gases to protect are options to reduce oxi of must
○ Thick, high sugar content grapes can be hard to press, clarify and ferment
○ Often mat in oak (old or new) esp for neutral grapes (eg Semillon) -> gives more texture and new oak can add tannin and some flavors (vanilla)
○ Aromatic var - tend to be stored in s/s or concrete to preserve varietal aromas
