Fermentation & Still Wine Production Flashcards
The science of winemaking is known as
Enology
The prefermentation portion of winemaking is often broadly referred to as the
Crush
Methods winemakers use to protect just picked grapes from degrading are
Covering them, cooling them and using sulfer to protect against fermentation.
SO2 is the combination of
Sulfur and oxygen to become Sulfur Dioxide
What does Sulfur Dioxide do when added to grapes or juice?
Inhibits the growth of yeast and bacteria which reduces the chance of premature fermentation. Also prevents the juice from oxidizing and turning brown.
The first step in grape reception is called
Sorting
List the pre-fermentation steps of white wine production.
Sorting Crushing/Destemming Pressing Must Adjustment Settling
Define whole berry or whole cluster pressing.
Rather than de-stemming and crushing the entire bunch are pressed together.
What is the difference between crushing and pressing?
Crushing is piercing the skins of the grapes, pressing is the compressing of the grapes and solids several times.
How can a “cold soak” benefit a white wine?
With the skins macerating with the juice more aromas and phenolics are extracted. This is good for the more aromatic grape varieties.
How long does a “cold soak” last for a white wine.
No longer than 24 hours.
What is free run juice?
The juice that is released when the grapes are put into the presser.
What is the cake of dry compressed skins and seeds called?
Pomace
Two examples of pomace brandies are
Grappa and marc
Grape juice that’s destined for fermentation is called
must
What is acidification?
The addition of tartaric acid in the must needed for balance.
What is chaptalization?
The addition of sugar in the must for wines that might not end up with enough alcohol. Not for sweeter wines!
A chaptalized wine is sweet. T or F
False
What are some other methods of raising or lowering acid or sugar in the must?
Adding water to dilute, adding grape juice or concentrate.
The process of letting the must settle before fermentation is called
Juice settling.
The smaller molecules that remain after the east cells have split apart the sugars are
Ethyl alcohol and carbon dioxide
What percentage of the grape sugars are converted into alcohol before fermentation stops?
90%
White wines are sometimes fermented in what size barrels?
60 gallon oak barrels
Oak barrels are used in white wine fermentation to add
Complexity, oak flavors and downplay fruit aromas
What two methods do winemakers use to keep fermentation from starting before they are ready?
Addition of sulfur and/or refrigerating the must.
The yeasts mainly used in winemaking are strains of
Saccharomyces cerevisiae
Why are different strains of yeast used?
Different strains impart different flavors aromas, speed or slow the fermentation process or achieve a certain level of alcohol.
What the optimal temperature for white wine fermentation:
50 - 60 degrees
Cooked fruit or applesauce aromas in white wines occur at high or low fermentation temperatures?
High
At what temperature will yeasts die and fermentation will stop?
100 degrees
A normal white wine fermentation will take how long?
Several days to several weeks
At what alcohol level will fermentation halt?
14%
Yeasts die at what alcohol level?
14%
A typically produced dry white wine will have an alcohol content of
12 - 14%
What ester is created as a byproduct of a white wine MLF and what aroma does it impart?
Diacetyl - a “buttery” aroma
What white wine benefits from MLF?
Chardonnay
What is the term for the sediment at the bottom of the fermentation tank or barrel.
Lees
The method of gentle clarification is called
Racking
Why would a winemaker allow a white wine to rest sur lies?
The dead yeast cells impart a creamy texture and increased complexity to the wine.
What is battonage?
The french term for stirring of the lees.
Additional sulfur may be added to post fermented white wine why?
To keep the wine from oxidizing and keep it from a secondary fermentation after bottling if there is residual sugar.
Three methods of clarifying white wine before bottling are:
Fining, filtering and centrifuge
List three filtering agents.
Gelatin, egg whites, bentonite clay
What is sterile filtering?
Technology that filters out all microbes.
Wine diamonds are called?
Tartrates
To prevent tartrates from developing in a white wine bottle what process is used before bottling?
Cold stabilization
Cold stabilization occurs at around what temperature?
25 degrees
How long will a cold stabilization last before the white wine is racked and bottled?
1 - 3 weeks
List the post-fermentation steps in white wine production.
MLF (if desired) Lees contact (if desired) Sulfur addition Clarification Barrel Aging (if desired) Blending Cold Stabilization (if desired) Bottling
List the prefermentation steps for red wine production
Crushing/Destemming
Must adjustment
Maceration
Insufficient tannin in red wine production can be adjusted by the addition of what two things?
stems and tannin powder
The color components of most red grape varieties is located mainly
In the skins
The immersion period where red grape skins stay in contact with the juice is called
Maceration
How long do red grapes macerate?
a few days to a few weeks or longer
The length of maceration time for red grape production is based on
the grape variety and the intended style
Longer maceration periods yield red wines that are
highly tannic, highly “extracted”, deeply colored, and will need more time in the bottle.
Shorter maceration periods yield rad grapes that are
softer, lighter in color and ready for consumption
Name 2 red grapes that require less maceration time.
Cabernet Sauvignon and Syrah
Name a red grape that requires a longer maceration period.
Pinot Noir
What is a red wine production cold soak?
When a longer maceration period is needed they will macerate the grapes in a cold environment so that fermentation will not start.
Define cap management in red wine production.
The skins and solids will float to the top during fermentation and must be pushed back down into the juice.
What bacteria can potentially grow on the cap in red wine production?
Acetobactor
List the 4 methods of red wine cap management.
Punching down
Pumping over
Rack and return
Rotofermentation
The French term for pumping over is
Remontage
The French term for punching down is
Battonage
The French term for rack and return is
Delestage
At what temperature would a light fragrant Pinot Noir be fermented?
60 - 70 degrees
At what temperature would a tannic cabernet sauvignon be fermented?
85 - 95 degrees
Why are red wines fermented at higher temperatures than white wines?
The higher temperature allows for increased extraction of phenolics, desirable in reds.
Why would a winemaker continue maceration even after fermentation has ended?
To extract more tannins and color.
The addition of lactic acid bacteria post fermentation begins what?
MLF
Tannin molecules joining together is called
Polymerization
Why are oak barrels beneficial to tannic red wines?
They soften the tannins by allowing oxygen to reach the wine resulting in polymerization.
Mid to upper level powerful red wines age in new or old oak barrels?
New
After how many years will an oak barrel begin to lose it’s flavor components?
4
What is the term for a standard size (60 gallon) oak barrel?
Barrique
What are the two principal sources for oak used for barrels?
France and US
What’s the difference between French oak and American oak?
French oak has a tighter grain making it more subtle and refined in flavor.
How do winemakers choose their barrels?
Shape, size, type of wood, light, medium or heavy toast.
What are alternatives to oak barrels?
Oak chips or planks.
What is micro-oxygenation?
Pumping slight amounts of oxygen into the wine to try to simulate the oxidation of oak aging.
The method of red wine fermentation where whole bunches ferment w/o outside yeast or oxygen is called
Carbonic maceration
What light red wine uses carbonic maceration to achieve it’s fruity character?
Beaujolais
Describe the resulting wine of a carbonic maceration fermentation.
The wine will be more fruit forward, less tannic.
In rose production the crushed red grapes are fermented with the skins for how long?
Depending on the intended result, but a few hours to several days.
The method where a light rose and a concentrated red are made from the same batch of grapes is called the
Saignee method.
What is the direct press method in rose production?
The grapes are crushed and pressed resulting in a pale pink juice. Think Provence.
Direct Press method of rose wines is often referred to in France as
Vin gris
Rose is usually produced with MLF, lees stirring and oak aging. T or F
False
Roses that are slightly sweet are often called
Blush wines
What is the term for rose wines in German?
Weissherbst
What is meant by “flying winemakers”?
Winemakers who harvest both in the Northern & Southern hemispheres in the same year.
List ways sweet wines are created by both viticultural practices and by wine making techniques.
Botrytis, late harvest, drying, freezing, refridgeration, adding sweetness and fortifying.
How does botrytis affect the grape.
The fungus causes the grape to lose water leaving concentrated sugar.
List 2 grapes with a particular affinity to botrytis.
Chenin Blanc and Semillon
Late harvest wines work best in what kind of climate?
Cold
What grape varieties work best as late harvest wines?
Reisling and Chenin Blanc due to high acidity
What method is used to produce Italy’s sweet Amarone wine?
Drying
How is ice wine produced?
Freezing the grapes, then pressing quickly to get only the sugar juice.
What grape varieties work best for ice wine?
Reisling, Gewurtztraminer, Chenin Blanc (Cab Franc rarely)
The mechanical freezing process used to produce sweet wine is called
cyroextraction
Wines made with 95% organic grapes can use the term “Organic Wine”. T or F
F. Must be 100%
What is the most significant restriction in organic winemaking?
No use of sulfur
Rabbinical supervision is required for what parts of the Kosher wine production and consumption?
Grape arrival to winery through bottling, and then once the bottle is opened.
What is mevushal wine?
It is kosher wine but without the restrictions. It is flash pasteurized before leaving the winery.
Orange wines are thought to have originated in
The Republic of Georgia
Orange wines are made from red or white grapes?
White
The French term for juice settling is
Debourbage
