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Why is sulfur used before fermenting white wine?
- To prevent browning, microbial spoilage, and offset the oxidative process
- Sulfur extends shelf-life
How much sulfer is added before fermentation?
How much sulfites are produced during fermentation?
Why is less sulfur used currently?
- Improved winery hygiene
- Sulfur levels have dropped 30%-60% over the past 30-40 years
Are white grapes crushed?
- Historically, but now clusters are pressed gently
- This results in a cleaner must
What is the purpose of skin contact for white wine?
- Boosts aromatic profile (when followed by temperature-controlled fermentation)
- Grapes must be mature and devoid of rot
For white wine, does skin contact occur in the press or in a tank?
- For sound fruit, extended press time (a few hours) pulls flavor compounds and aromatics from the skin
- If skin contact occurs in tank, nitrogen is used to displace the oxygen
At what temperature is white wine fermented?
- Juice is chilled to 59°F (15°C)
- Fermentation runs between 65-68°F (18-20°C)
What is the difference between fining and filtering?
- Fining removes unstable proteins (too small to be removed by filtering)
- Filtering removes larger particles (e.g., grape cells, yeasts, microorganisms)
What is fining and why is it done?
- A clarification process to remove proteins (unstable colloids)
- Prevents haze
- Removes some tannins to improve balance
Are white wines fined with bentonite and lightly filtered?
What is Bentonite?
- An alumino-silicate clay formed from volcanic ash used as a fining agent
- Its small particles have a negative charge in wine, ideal for removing positively charged protein molecules
- Not to be confused with Kieselguhr earth, used as a filtering agent
Define 5 French winemaking terms
- Egrappoir: de-stemming machine
- Debourbage: juice settling
- Pigeage: punch-down
- Remontage: pump-over
- Batonage: lees stirring
Why is Debourbage important?
- It eliminates heavier particles (bitter phenolics) before fermentation
- Cloudy must results herbaceous, bitter, reductive wine with reduced varietal character
Are most fermentations started with cultured or wild yeast?
Since the 1980s, cultured
Are white wines fermented in tank or barrel?
- Some (e.g., Pessac-Leognan) are barrel-fermented but many are tank-fermented
- Barrel fermentation is usually accompanied by sur lie aging and batonage
Describe rules regarding cremant production
- Grapes must be hand-harvested
- Base wine can use any (red or white) AOC grape
- Must be aged at least 9 months on its lees
- Must achieve minimum pressure of 3.5 atms
- All cremant is dry
Name the 3 styles of cremant
- blanc de blancs
- blanc de noirs
How much cremant is produced (2009)?
- Dry rose sparkling: 1,890 hl on 55 ha
- Dry white sparkling: 10,680 hl (5.6X) on 185 ha (3.3X)
Name the two lightly-pigmented wines produced in Bordeaux
- Rose: pink (10-12 hours maceration)
- Clairet: semi-red (24-48 hours maceration)
- Grapes are crushed and tanked with skin contact
- There is no law mandating maceration time
How much juice is bled from the tank for saignee production?
Is malolactic fermentation used for saignee production?
Generally avoided to maintain freshness
What is "Sweet Bordeaux"?
Association of producers from the Cerons, Barsac, Sauternes, Loupiac, Sainte-Croix-du-Mont, Cadillac, Premieres Cotes de Bordeaux, and Cotes de Bordeaux Saint-Macaire
Name 4 European terms for Botrytis Cinerea
- France: Pourriture Noble ("noble rot")
- Germany: Edelfaule
- Italy: Muffa nobile
- Hungary: Aszusodas
When do Botrytis spores germinate?
- After a rain or when humidity is 90%
- Moderate temperatures (59-68°F, 15-20°C)
- Grapes must be ripe and at their flavor peak
- Takes 2-4 weeks of optimal weather to develop
What do grapes smell like when mature?
- Semillion: apricots
- Sauvignon Blanc: grapefruit or pineapple
- Muscadelle: overt grapiness
Name 4 compounds Botrytis transforms sugar and acid into
- Acetic Acid
- Gluconic Acid (found in honey)
- Botryticine (an antibiotic)
Compare the number of flavor precursors resulting from over-ripe vs botrytised grapes
- Over-ripe: 2X normal number of aromatic precursors
- Botrytis: 10X
When is the harvest for sweet Bordeaux appellations?
- mid-Sep to Nov (4-8 weeks)
- Multiple (6 times not uncommon) tris ("selections")
Describe assemblage for botrytized wine
- Harvest from each tris is pressed into a different barrel
- Over 15 days with 2 lots/day, 30 barrles will be assembled to create the finished wine
- Takes place after the first racking
What vinification techniques are used for botrytized wine?
- Sur lie aging with Battonage
- Matures in oak for 12-24 months
- Barrels topped up weekly and racked every 3 months
How much sulfur is added after pressing botrytized grapes and why?
- Biggest threat is acetobacter (oxidizes ethanol into acetic acid)
How and when is fermentation stopped for botrytized wine?
- Adding Sulfer
- When wine achieves alcohol to sugar ratio of 14:4 (or 15:5)
How many glasses of wine can be made from 1 vine's botrytized grapes?
How long does it take to press botrytized grapes?
- 5-6 hours
- Pressed with small bits of stems (to form channels within pomace)
- The last pressing delivers juice with most sugar (usually the reverse is true)
What is cryo-extraction?
- Chilling grapes to 17.6 to 23°F (-5 to -8°C) for 20 hours before processing
- Used if grapes have absorbed too much water after a rain as excess water becomes ice so only concentrated juice is extracted during pressing
- This practice has fallen out of favor
Why are vintage charts different for dry red and sweet white wines?
Weather conditions required to grow the grapes differ
When did Louis Pasteur discover yeast?
How do stems impact wine?
- Stems absorb sugar and acid during fermentation
- When green, stems impart bitter astrigency
- When brown, stems add a touch of spice
How did growers handle grapes before temperature control?
- Pick in the evenings or early morning
- Pick before sugar levels got too high
Describe historical red wine making
- Grape clusters de-stemmed by hand if at all
- Grapes crushed in wooden troughs
- Must transferred to wooden fermentation vat using a bucket
- It could take days to fill a fermentation vat
- No temperature control during fermentation
- 4-6 weeks of extended maceration
- Transferred to barrel to mature for 3 years
- Remaining slurry transferred by bucket to wine press
- After 2 pressings, press wine transferred to barrel
- Aging ("elevage") carried out by negociants who blended in wines from Rhone and Spain
Compare Bordeaux reds made in the 19th C with those of today
- Color: lighter
- Alcohol: lower (10% vs 13%)
- Tannin: up to 20% less
Describe modern red wine making
- Keen attention is paid to winery hygiene
- De-stemming is now mandated by law and carried out by machine (egrappoir)
- Grapes are pumped or gravity fed to fermentation tanks
- Different varieties are fermented separately
- Temperature-controlled fermentation in stainless steel tanks or lined concrete vats
- Some press wine added in weaker vintages to add tannin and pigment
- Second fermentation right after first, and often in barrel
- Wines are racked after malolactic fermentation and then the gran vin is assembled
- Wines are racked every 3-4 months
- After maturation, wines are fined with egg whites, bentonite, or gelatin
- Most undergo a light filtration but this step is optional
Is chaptalization legal in Bordeaux?
- Yes, but sugar levels at harvest have been rising so not usually needed
- Chaptalization is illegal if the juice has been concentrated
What temperature is red wine fermented at?
80-82°F (27-28°C) and finish at 86° (30°C) for 1 week
What does cuvaison mean?
Time in vat for red wine (1 week fermentation plus extended maceration... 2-4 weeks total)
How is malolactic fermentation started for red wine?
- Concrete vats retain warmth (from alcoholic fermentation) so it starts spontaneously
- Stainless steel tanks must be heated
Who performs the aging?
Since the 80s, aging is carried out by the chateau, not by the negotiant
How long is red wine matured?
- Grand vin ages 18-24 months on average
- Some classified growths use 100% new oak
- Wines with less structure get less new wood and are aged less
Does red wine naturally cold stabilize?
- Yes, over winter; can also be induced.
- Tartaric acid precipitates out as tartrate crystals in barrel.
How do you eliminate excess water in the grape if it rained at harvest?
- Today, using reverse-osmosis machines (expensive) or a "concentrateur" which uses pressure to evaporate water
- Historically, by bleeding 15% of the juice prior to fermentation (to increase skin to juice ratio)
- However, bleeding results in sugar and aromatics in the rose rather than the red wine
Describe the red winemaking calendar
- Harvest: Sep/Oct
- Alcoholic fermentation: Oct
- Malolactic fermentation: Nov
- Assemblage/tasting: Dec
- Transfer to barrel: Jan
- Racking/tastiung: Mar