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88 Cards in this Set

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What is enrichment?
adding concentrated grape juice to the must to increase flavor and alcohol levels
What did stainless steel tanks do for winemaking?
1) improved hygeine because they can be more thouroughly cleaned,
2) allowed more white wine making in warm climates because the tanks can be cooled during fermentation which retains fruit flavors
List some modern vinification improvements that can improve the quality of wine
1) development of yeast strains,
2) control of malolactic fermentation
3) reverse osmosis for de-alcoholization
4) cryo-extraction devices
5) irrigation technology
6) clonal selection of grape varieties
Name two types of grape presses?
bladder aka pneumatic, and basket presses
What is the major difference between red and white winemaking
the point when pressing occurs. White wines are pressed right away before fermentation occurs so the juice does not become colored. Red wine is allowed to ferment on the grape skins and it is not pressed to separate juice from solids until fermentation is mostly done
For white wine making, when does pressing (separating liquid from solids) occur?
before fermentation starts so skin color is not imparted to the wine
Why should must be chilled and sulfured (SO2) before pressing?
to avoid an early start to fermentation from wild yeasts and oxidation from wild bacteria
Whole bunch pressing is most commonly used in the production of what type of wines?
Sparkling
What types of yeast are used in wine making?
ambient/wild, cultured, or both
Why are cultured yeasts added?
1) To control the flavors of fermentation.
2) To prevent a stuck fermentation because many wild yeasts do not work after 4% alcohol level is reached
3) To speed up fermentation before wild bacteria can spoil the must
4) To start fermentation if wine has been filtered prior to fermenting which removes the wild yeasts
at what temp should white wine be fermented?
cool: 50 - 68 deg. F (10-20 deg. C)
At what temperature should red wine be fermented?
warmer temps, 70-80 deg. F
Fermenting a wine to dryness is quicker at what type of temperature?
warmer temperatures but if too warm, flavor is lost
What risk do you run at fermenting white wine at warmer temps?
burning off fruit flavors
What are the 2 basic types of fermentation vessels?
inert and reactive
For light/aromatic whites, it is best to ferment in what type of vessel?
stainless steel tanks
What are the advantages to ferment in stainless steel?
hygiene, easily cleaned, tempereature control, re-useable, less expensive than barrels in the long run
List some inert vessels used for wine fermentation
cement, glass, old wood lined with glass or tartrate crystals
What do reactive fermentation vessels do?
impart flavors into the wine
What are some of the influences of fermenting wine in oak
oak can add some tannins and vanillin or toasty flavor
What are some of the drawbacks of using barrels in winemaking?
1) sterility issues - barrels are harder to clean
2) no temperature control
3) more small vessels to watch over
4)negative oxidation,
5)expense - initial cost, labor, leakage, evaporation
What types of corrections can be used for white wine?
chaptalization, acidification, and de-acidification
what is chaptalization?
addition of sugar to the must before or after fermentation to increase the alcohol content - from Chaptal: Napoleon's agricultural minister who wanted to support the sugar beet industry
What types of sugars are used for chaptalization?
beet, cane, concentrated must, or grape must
what is acidification?
acidification is the adding of acid, usually tartaric acid, to the wine usually in warm climates where natural acidity is less at harvest
What are the types of acids usually found naturally in wines?
citric, tartaric, and malic acids
What type of acid is most used for acidification?
tartaric
What is MLF (malolactic fermentation)
it is conversion of harsh malic acid to softer lactic acid and CO2 by leuconostic oenos bacteria
What slows down malolactic fermentation?
high alcohol levels and high sulfur levels
What grape varieties are most associated with malolactic fermentation?
Chardonnay as a white grape and almost all red grapes undergo malolactic fermentation naturally by letting the fermentation reach warm temperatures
Are aromatic grapes associated with malolactic fermentation?
rarely
What is battonage?
stirring of the lees to more fully extract color, flavor and tannins
What does extended time on the lees impart on a wine?
creamy, bready flavours of the yeasts such as in a Muscat sur Lies
Name 2 types of finishing for white wines
fining and filtration
What is fining?
removing suspended particles/colloids in wine that may make it cloudy if left in
List 4 types of fining agents
albumen, bentonite clay, isinglass, gelatin, casein
What is filtration and what are two types of filtration?
filters remove particulate (not dissolved or ionized) matter in a wine. Depth filters are most commonly used but wines with a residual sugar content use a surface (membrane filter) which also removes yeasts and bacteria which could further ferment the residual sugars
What is cold stabilization?
an optional winemaking step that chills the wine to precipitate tartrate so they do not form in the bottle afterwards. It is largely cosmetic.
What are two types of blending?
1) grape types can be mixed during pressing
2) fermented juice (wine) from different grape types can be mixed after fermentation but before fining
What is most essential during bottling?
sterility
List three different types of wine stoppers
natural cork, agglomerated corks, synthetic corks, glass, stelvin screw caps, crown caps
What is the saignee method of producing a rose wine?
saignee- removing the juice from the must very early so the coloring of the wine just gets a light red tint from the skins
Why must a winemaker have access to red wine during fermentation?
To keep the must cap moist to prevent harmful bacteria to build up if it dries out
What type of yeast is common for red wine fermentation and why?
wild/ambient yeasts because they cover the skins that are left with the juice during fermentation
Why are cultured yeasts useful?
they are predictable in terms of fermentation temperature and generally produce consistent flavors. They may require specific nutrients
What does the must cap do during red wine fermentation?
it protects the wine from oxidation
What is pigeage?
punching down of the must cap to keep it moist and to increase the color and flavor of the wine
What is remontage?
remontage is pumping of red wine from the bottom of the tank over the cap to keep it moist and submerged to extract all the color and tannins
What are 2 types of modern improvements to pigeage and remontage?
screens to keep the cap down and roto-fermenters
After fermentation, what happens to the must cap?
it sinks, the wine must be chilled, sulfured, and the tank closed to protect the wine from oxidation
What is vin de goutte?
This is the wine (considered the finer wine) that is drawn from the fermentation tanks simply by the flow of gravity and with no pressing
What is vin de presse?
This is the wine that is drawn from the fermentation tanks by pressing down on the contents ... it is a bit more tannic and rougher than the "vin de goutte" wine
What is the difference between vin de goutte and vin de presse
vin de goutte is fruitier and finer vs presse which is more tannic and bitterer.
What can press wine be used for
blending with free run juice, topping off, lesser wines, sold off
What is battonage?
lees stirring
what does time on lees impart on a wine?
creamy, bready flavours of the yeasts
What does malolactic fermentation do for red wine?
malolactic fermentation softens acidity, adds complexity, stablizes
Does red wine get clarified, and if so, when?
sometimes red wine is clarified, usually between fermenatation and maturation
What types of wood are used for barrels to ferment and age wine?
oak, cherry, chestnut
Other than using wood barrels what are some other ways to get oak in wine?
staves, chips added in to stainless vessels
What is wine racking?
transferring wine from one vessel to another to reduce odors, and remove particles
Define topping up.
keeping barrels full to leave no room for air which causes oxidation
What do you top up wine in barrels with?
wine of the same or better quality
Is filtration more or less common in fine red wines?
less common
Where do tannins in wine come from?
tannins come from the pips, skins, stalks, and wood barrels if they are used
What is an oak container that holds hundreds of liters?
foudre or botti
What do the different anatomical components of the grape contribute to the wine?
stalk - tannins
bloom (waxy coating on outside of grape) - wild yeasts and bacteria (lactobacillus)
skin - coloring, tannins and flavor compounds
pulp - water, sugar, acids and flavorings
seeds - bitter oils, tannins
What is carbonic maceration?
it is an alternative form of fermentation in which the grapes are left whole with stems and all to ferment without crushing. The grape ferments internally and then breaks open. There are very little tannins produced this way and very fruity flavor is preserved. Esters of bubblegum, banana, cinnamon-like spice and kirsch are more prominent. Beaujolais Nouveau is made this way.
What is the saignee method of fermentation and when is it usually used?
saignee fermentation requires the red grapes to be destalked and lightly crushed, not pressed. This is vatted for 12-24 hours to extract some red color to make rose wine.
Can rose wines be made from blending a red wine and a white wine?
Yes. Anywhere in the world red and white wine can be blended to produce a rose wine except in the European Union with the exception that it is allowed in the Champaign region of France.
What are the best temperature ranges for fermentation of white wines?
Optimum temperature for fermentation of white wines is 14-20 deg C (57-68 deg F)
Aromatic white wine might be fermented at 11-15 deg C (52-59 deg F) and even lower temps of 10-13 deg C (50-55 deg F) by winemakers to retain maximun volatile esters.
What are the best fermentation temperatures for red wines?
Optimum temperature for fermentation of red wines is 25 deg C (77deg F) with a range of 20-32 deg C (68-90 deg F)
What are three methods of treating wine to remove excess iron before bottling?
Citric Acid forms soluble iron citrate
Gum Arabic prevents precipitation of ferric colloid
Ascorbic acid (Vitamin C) prevents iron occidation
What are three methods of treating wine to remove excess copper before bottling?
Blue fining (potassium ferrocyanide) for levels above 1 mg/l
bentonite fining
gum arabic
What are 4 benefits of punching down (pigeage) as a cap management technique?
Gentile extraction of tannins and anthocyanins.
Harsh/bitter compounds are less likely to be extracted from the seeds or stalks.
Good dispersion of temperature.
Avoidance of bacterial spoilage on the cap.
What are 6 benefits of pumping over (remontage) as a cap management technique?
Simple to perform with minimal equipment.
Excellent extraction achieved.
Heat from fermentation is dispursed.
Must is aerated avoiding reuction problems.
Oxygen exposure benefits yeast activity early on.
Prevents the pomace cap drying out.
What is the purpose of cold soaking of red grapes before fermentation?
Destemmed and crushed grape must is cooled to below 15 deg C (59 deg F) and bathed in more SO2 for 3-7 days to aid in color extraction.
What type of filtration is rotary drum filtration:
1. Surface
2. Depth
3. Cross
4. Absolute
5. Heat exchanger
Depth filtration. It uses diatomaceous earth with a vacuum pulling the must through it.
Name 5 types of clarification of wine.
1. Sedimentation and racking
2. Filtration
3. Fining
4. Centrifugation
5. Flotation
Name 3 types of filtration used to treat wine.
Depth filtration
diatomaceous earth/perlite
sheet or pad filtration
Surface filtration
membrane
cross flow
Specialized filtration for components such as tannins, sugars, acids, alcohol
ultrafiltration
reverse osmosis
osmotic filtration
List 5 different types of grape presses and their main advantages..
Vertical screw press -simple, juice filtered thru stalks
Horizontal screw press - pressing can be automated, filling simplified
Pheumatic press - good liquid extraction, reduced bitter phenolic extraction
Tank press - decreased oxygen contact
Continuous screw press -high throughput can be achieved
What are 3 benefits of autovinification?
No external power is required.
Reduced labor requirements due to automation.
Maximum color and tannin extraction in a short time.
Why is the permitted level of SO2 for the sweet white wines higher than it is for dry reds?
Sulfur is less available in the active form due to the binding power of sugar.
List 3 substances in grape must that can be removed by reverse osmosis.
Water
Alcohol
Acids
What is the 'contact process'?
A method for making the wine tartrate stable. Wine is chilled to 0 deg C and potassium tartrate crystals are added which act as nuclei for further crystal growth and precipitation.
What is hyperoxidation used for in winemaking?
Oxygenation of the must by bubbling O2 for a calculated length of time through the juice prior to fermentation can lead to the development of more complex aromas and flavors in some white wines such as Chardonnay (but not Sauvignon Blanc)
What is flash expansion as a red winemaking technique?
Preheated grapes (65-90 deg C) are placed in a vacuum which immediately cools them to 30-35 deg C which breaks the cells and gives a rapid release of anthrocyanins and tannins. Skins are no longer needed so juice can be drained off and fermented like white wines but with less need for refrigeration.
What is delestage?
Rack and return. Fermenting must is pumped out of the fermenting vessel into another and then pumped back over the top of the cap which has fallen to the bottom of the tank. This extracts tannins and color pigments efficiently but allows removal of seeds and their bitter tannins.