Viniculture Flashcards
What are the 4 prevalent mineral elements in wine?
potassium, calcium, copper, iron
What is lenconostoc used for?
malolactic fermentation
What is the influence of extended skin contact on tannins?
It gives time for short-chain tannins to link up and form long-chain polymers.
How does extended skin contact help enzymes?
There is enough time for the enzymes to disassemble cells in the skins, which allows everything the skins have in the way of color, flavor and fragrance to enter the wine.
What is a good temperature for fermenting red wines?
80-85 degrees F
Rotundifolia is usually deficient in what?
Nitrogen
What is a slow-eating yeast often used for Pinot Noir?
Assmanhausen
What is Flor Sherry yeast?
Saccharomyces fermentati - AKA UC Davis 519
The culture needed to produce flor or fino-type sherries in hot, dry regions.
What is Epernay 2 yeast?
Saccharomyces cerevisiae
A slow-fermenting, general purpose strain. Used for reds, whites and sparkling.
What is California Champagne yeast?
Saccharomyces bayanus - UC Davis 505
Slow to moderately vigorous, with extremely rapid, compact precipitation of spent yeast lees. Facilitates riddling of bottle-fermented sparkling wine.
What are the characteristics of Pasteur Champagne yeast?
Developed by Pasteur Institute and numbered UC Davis 595. Moderately vigorous with high SO2 and alcohol tolerance. Used for all wine types but especially for sparkling wines and stuck fermentations.
What is Montrachet 522?
A popular strain of Saccharomyces cerevisiae.
When is the yeast added?
About a day after the sulfite is added.
Reds with a pH less than 3.3 tend to resist what?
malolactic fermentation
Where is it possible to see high TA and high pH?
Washington State
What are two safe ways to reduce acid?
- Inoculate the must with malolactic bacteria toward the end of the primary fermentation.
- Cold stabilize the wine
TA minimum for reds is what?
Whites?
- 55
0. 65
If the pH rises, how could sulfite amount be changed?
raised
Too much SO2 can do what to a must?
Destroy tannins and flavor constituents
The FDA allows how much sulfite in wine?
350 ppm
What does the Walthari method use instead of sulfite?
Carbon Dioxide
What do winemakers use to kill off or stun into stupefaction all yeasts and microorganisms in the must as soon as it’s pressed?
potassium metabisulfite
Many yeasts die off at what percent alcohol concentration?
4-6%
Why do white grape varieties give a greater yield of juice after 16 hours of skin contact?
Due to the softening and enzymatic breakdown of cells in skins and pulp.
What do fruit flies carry?
Acetobacter bacteria
Why is it a bad idea to cool grapes by hosing them with cold water?
It will immediately reduce the quality of the grapes by producing conditions for bad mold spores and off-flavored yeasts to multiply.
When should grapes be crushed?
Immediately after picking.
What is “topping up”?
Adding a second and similar wine to a vessel to fill it up, when the wine you have doesn’t reach the top.
What is “sticking”?
A stoppage of fermentation before sugar is entirely converted to alcohol, usually due to yeast dying off from lack of nutrients or to chilling.
What is a hydrometer?
An instrument for measuring the specific gravity of liquid.
What is enology?
The science of winemaking.
What is an airlock?
A device that allows gas to escape from a vessel containing wine, but allows no air to enter.
What is bousinage?
Toasting a wooden stave.
What is cintrage?
shaping a wooden stave
What is chauffage?
warming a wooden stave
How is American oak usually dried?
In a kiln
How is French oak usually dried?
In air
Which oak is less likely to be sawed?
French
What causes wider grain in oak?
quicker growth
