Chapter 17 - RS Wines Winemaking Flashcards
What are the 3 ways to make RS wines?
- Concentrate the sugar in the grape must
- Stop the fermentating before dryness
- Add sweetening component to the wine
What is the natural way of stopping fermentation before dryness?
How can a winemaker stop fermentation?
- If the sugar content is high enough, fermentation stops naturally because yeast do not work well in high sugar environments with alcohol present
- Winemakers can chill the wine or add SO2, and then filter out the yeast and sterile filter
What are the methods of concentrating grape must?
- Drying the grapes on or off the vine
- Freezing the grapes
- Noble rot
Describe the 2 ways of drying grapes on the vine and where each method is used
- Naturally, if grapes are left on the vine after ripening, it begins to lose water through grape transpiration and the sugar and aromas start to concentrate. This stage will still further develop the flavors in the grape adding on riper and dried fruit qualities. Dry autumns are crucial for grey rot to not affect the grapes
Used in Vendanges Tardive in Alsace and Spatlese in Germany/Austria - Removing the cane from the vine just before harvest. This allows the grapes to shrivel quicker, while still concentrating the sugars, acids, and aromas. This also reduces the risk of grey rot.
IMPORTANTLY, this method does not allow extra ripe flavors to develop
Sweet wines from the Jurancon and Australia
Describe the 2 way of drying off the vine
In both methods, the grapes are picked first
1. Dried outside - in warm climates, the grapes are laid out in the sun to dry
Vin Santo from Southern Italy, Spain
2. Dried in a temperature and humidity controlled room. This helps speed up the process and prevent the growth of noble rot but is more costly
Recioto di Valpolicella
In both, water is evaporated, causing sugars, acids, and aromas to concentrate. The appassimento method
What is the fungus that causes noble rot? How is noble rot different from grey rot?
Botrytis cinerea
Both are from the same fungus. Just depends on the environment and if the right conditions are present for the fungus to benefit the wine
What are the conditions needed for noble rot wines? What regions are known for botrytised wine?
- Wines must be fully ripen before affected by noble rot
- Grapes must be in an environment with humid mornings and dry afternoons - humid mornings allow the rot to develop on the grapes. Dry afternoons allow the water to evaporate out of the grape and stall the rot development
- The fungus punctures the grape skin, leaving tiny holes. The fungus also modifies the aromas, giving it honey, apricot, citrus zest, ginger, and dried fruit aromas
Sauternes, Beernenauslese, trockenbeerenauslese, Tokaji
Why are noble rot wines expensive?
- Skilled labor is needed over a prolonged period of time.
Pickers need to know which grapes are good to be picked and many passes are required because the grapes are not all affected at the same time by the fungus - Noble rot is not guaranteed every year therefore scarce- some years where it is too wet can lead to crops getting destroyed by grey rot.
- These wines are not easy to process because the fungus contributes and enzyme called laccase. Laccase oxidizes a number of components in must and wine and is resistant to SO2
- The thick sugary must is difficult to press, clarify, and ferment
- Oak maturation is often used for nonaromatic grapes like semillon for more texture and aromas (aromatic grapes will be aged in ss or concrete to preserve varietal aromas)
What is the process of making icewine/eiswein? Where is it popular?
Healthy grapes are left on the vine into winter
When freezing temperatures arrive, the water in the pulp turns to ice
The grapes are then picked
When they are pressed, the ice is left in the press, thus concentrating the sugars
Eiswein in Germany, austria
Icewine in Canada
What temp must Canadian icewine be harvested at?
-8C or below
What is required of the vines for freezing grapes?
Vines must be hardy nad have grapes with resilient skins against disease and freeze-thaw cycle strains
What are the most popular varietals used for freezing grapes?
Riesling, Vidal, sometimes Cab Franc
What are the risks to freezing grapes?
- Pests - netting against birds is an important cost in ice wine production
- Disease
What is the artificial freezing grapes method called? How does it work?
Cryoextraction
Grapes are picked during regular fall harvest and then froze in the winery
Eliminates the risk of pests, disease
These cannot be labelled as eiswine or icewine
What is the advantage of stopping the fermentation?
The winemaker has full control over the level of sugar in the final wine
The process is relatively quick, simple, low risk. Therefore great for inexpensive, midpriced wines
