Vinification

Question 1

Explain alcoholic fermentation

Answer 1

The metabolism of yeast cells
converts sugar in grape must
into ethyl alcohol (ethanol) and carbon dioxide (CO2).

Question 2

What the the bi product of alcoholic fermentation?

Answer 2

Ethyl alcohol
carbon dioxide
sulfur dioxide

Question 3

Explain why vessel choice for fermentation is important

Answer 3

The amount of heat generated by fermentation increases with the size of the must—without accounting for any temperature control, small vessels provoke slow, cool fermentations and large vessels lead to short, hot fermentations

Question 4

a) At what temperature is yeast dormant?

b) At what temperature will yeast die?

Answer 4

a) below 10 Celcius

b) above 45 Celcius

Question 5

What is the benefit of hot fermentations for red wines

Answer 5

increased extraction of color, tannin and flavor compounds.

Question 6

Pros and cons of Barrel fermentation?

Answer 6

Barrel fermentation, on the other hand, lacks temperature control but the relatively small size of the vessel prevents temperatures from rising too high
Barrel fermented wines are generally subject to the processes of lees contact and bâtonnage, or lees stirring, which add further complexity and richness

Question 7

Chapitalization is what?

Answer 7

the addition of sugar to the must to increase the final alcohol and glycerin content of the wine

Question 8

What is reverse osmosis?

Answer 8

Alcohol adjustment
Separating the wine into two constituent parts,
Permeate and Retentate
The permeate, which contains water and ethanol, is then distilled to a proper level before being recombined with the retentate—the wine’s aromatic compounds—at a lower percentage of alcohol.

Question 9

Acidification is what?

Answer 9

the addition of acid to must or to a finished wine. Tartaric acid and malic acid, the two principle acids in grape juice, may be used for acidification; tartaric acid, added prior to fermentation, is preferred.

Question 10

Explain Malolactic fermentation

Answer 10

lactic acid bacteria convert harsh malic acids into softer lactic acids and carbon dioxide. It rounds out a wine’s texture.

Question 11

Cold stabilisation happens at around what temperature

Answer 11

-3.8 Celcius

Question 12

What trees are used for French oak?

Answer 12

Quercus robur
Quercus petraea trees
Slow growing tighter grain
French oak is split

Question 13

What trees are used for American oak

Answer 13

Quercus alba,
a faster growing , wider grain
American oak is sawn and releases more vanilla and lactones

Question 14

What are the three stages on making a barrel

Answer 14

Three stages: warming (chauffage), shaping (cintrage), and toasting (bousinage)

Question 15

Polyphenols in red wine protect against oxidation

Answer 15

oxidation is more like to occur in white wine for this reason

Question 16

Microbioogical action can cause the formation of

Answer 16

acidaldehyde

Question 17

What can be done to avoid oxidation at bottle?

Answer 17

adding nitrogen to your closures

Question 18

lack of nitrogen in the must can cause the yeast to stress and result in a build up ff what?

Answer 18

H2S

the opposite to oxidation

Question 19

Anisoles

concentrated compounds

Answer 19

TCA - chlorine meets mould
TBA - wood preservatives, pesticide residue
TeCA - similar to TBA

Question 20

How many hexagonal cells(cork Lenitcels) does an average cork have?

Answer 20

800 million

Corks are graded between a- b - c

Question 21

ROSA system

Answer 21

Rate of Steam Application to reduce TCA

Question 22

Brettanomyces

Answer 22

Dekkera

A slow growing yeast
Occurs after primary fermentation, in barrel
usually happen as it begin Malo, and begins to get warm
develops easily in ripe, high alcohol, soft acid, high PH, which is why we see it less in whitesbn(Grenache)