Winemaking VEN3 Flashcards
How often is wine made?
Once a year. Grapes can only be harvested once a year
What is yeast and what does it do in terms of winemaking?
Eukaryotic microorganisms part of the fungus kingdom. Yeast helps convert the sugar in grapes to carbon dioxide and alcohol during fermentation.
What is the acidity of wine and the importance of the acidity?
Wine ranges a pH of 2.5-4.5 but usually sits around 3.2-3.5. The low acidity along with the alcohol means that no bacteria or diseases can grow making it one of if not the most hygienic beverage
Sweet vs. Dry Wine
Sweet contains remaining sugar and have a sweet taste. Dry wines have little to no sugar remaining.
How much alcohol is contained in wine?
5.5-20% but usually around 12-14%
What are tannins?
Large molecule called polyphenols. Tannins interact with our saliva and protein in them to give wine bitterness and astringency. Found in skin and seeds
What are the five types of wine?
White wine, Rose wine, Red wine, Dessert wine, and Sparkling wine
What is fermentation?
Biological process where sugars in the grapes are converted by microorganisms into alcohol and carbon dioxide.
Still vs. Sparkling wine
Still wine contains less than 1 atmosphere of CO2 (<3.92 grams of CO2 per liter)
Sparkling wine contains more than 1 atmosphere of CO2
What is a field blend?
Where different varieties of grapes from the same vineyard are picked and crushed together
What is a wine blend?
Mixing new or old wines that were fermented separately
What is varietal labeling?
Only 75% or more of the grapes used for the wine be of the stated variety
Yield=
Tons/acre
What country has the largest surface area of vineyards?
Spain
When is bud break?
April 1
What is veraison?
Onset of ripening
What does a refractometer do?
Refracts light to determine the brix
How do you calculate degree days?
When average temperature is >50 degrees, -50 of average then add to total number.
What is must?
Crushed grapes (Juice)
What is Brix?
Percentage of sugar (Mostly glucose and fructose)
What is Pomace?
Seeds and skin after pressing
What is the scientific name for Wine Yeast?
Saacharomyces cerevisiae
What does respiration do?
Breaks down carbon for energy. Converts sugar to CO2 and water. Requires oxygen
What does fermentation do?
Produces ethanol, CO2 and heat. No oxygen required
1 degree brix drop = how much rise in temperature?
2.3 degrees
What temperature is too hot for yeast?
100 degrees
How do you calculate ethanol yield?
Brix x .55 = ethanol yield
What temperature and length is red wine typically fermented at?
High 80s to low 90s; 5-7 days
What is malolactic fermentation?
Secondary fermentation in which lactic microorganisms using malic acid in grapes to produce lactic acid and CO2 as well as diacetyl
Is Wild Yeast or Wine Yeast sensitive to SO2
Wild Yeast
What are the three kinds of presses?
Continuous, basket press, tank press
What is racking?
Transfer of juice or wine away from lees
What is lees?
Solid material in juice/wine
Why fine a wine?
To improve clarity, change wine’s taste, reduce tannin level, remove proteins, remove polysaccharides, and stabilize wine
What is tartaric stabilization?
Gets rid of tartaric crystals by chilling in a refrigerator or ion exchange
Why is red wine red?
Pigments in skin are extracted during fermentation
What is maceration?
Process of putting skin in contact with juice
When is extraction of color at its highest?
4-5 days
What is cap?
Layer formed by skins from CO2 bubbles separating skins from juice during fermentation
What are the two forms of cap management?
Pushdown and Pumpover
What kind of flavor and aromas to barrels give?
Oak and smokey
What is the average lifespan of barrels?
5 years
How many oxygen saturations are ideal for red and white wines?
2 for red wines and 0 for white wines
What is micro oxygenation?
Adding small amounts of oxygen over time to promote oxidative reactions
What are the two types of white wines?
Fresh/fruity and complex
What are barrels used for in red wines?
Aging
What is not produced in alcoholic fermentation?
Alcohol
Carbon Dioxide
More yeast
Diacetyl
Heat
Diacetyl
Volatile acidity is produced by…
acetobacter
How can you prevent acetobacter? 2 ways
Completely fill up containers so there is no oxygen or add SO2 to kill of acetobacter
Are red grapes or white grapes harvested riper?
Red grapes (More sugar)
What is free run?
Wine that comes out without pressing; Less bitter than pressed wine
On average how long are red wines put in barrels to age?
1-2 years
How are tartrates produced?
When a hydrogen ion on tartaric acid is replaced with a potassium ion
What temperature is white wine typically fermented at? How long do they take?
50-60 degrees to preserve fruit aromas and take 3-4 weeks
How is Chardonnay produced differently?
Barrel aged and fermented at a warmer temperature (70 degrees)
How much brix are champagne grape picked at?
18-20 brix
What is a base wine called?
Cuvee
What is the process of adding yeast and sugar and filling the bottles called?
Tirage
What is the process of riddling?
Gradually moving the bottle to get the yeast to collect at the top
What is the process of disgorging?
Removing the yeast from the bottle after riddling
Fermented in this bottle is what method?
Traditional method
What is chaptalization?
Adding cane sugar to must
