Composition and Chemistry

Question 1

What is the percentage makeup of the major components in wine by volume?

Answer 1

Water: 80-90%
Alcohol: 10-15%
Acids: 0.5-0.75%

Question 2

What is the term for the sum of all acids in a wine?

Answer 2

Total acidity, or TA. It does not measure strength

Question 3

What is the term for chemical strength of acids in wine?

Answer 3

pH

Question 4

What is the typical range of pH in wines?

Answer 4

2.9-3.9

Question 5

What is a typical range of sugar present in ripe grapes?

Answer 5

15-28%

Question 6

What is the largest group of odiferous compounds found in wine?

Answer 6

Esters

Question 7

Name two conditions that may promote the formation of hydrogen sulfide

Answer 7

Reductive winemaking and extended lees aging

Question 8

What specific reaction leads to the formation of mercaptans?

Answer 8

Combination of sulfur and ethanol (ethyl alcohol

Question 9

What is volatile acidity (VA)?

Answer 9

A detectable aroma of white vinegar due to acetic acid

Question 10

What is the term for the fault caused by the presence of VA in combination with ethyl acetate?

Answer 10

Ascensence

Question 11

What reaction leads to the formation of ethyl acetate?

Answer 11

Ethanol and acetic acid

Question 12

What is the general reaction leading to the formation of esters?

Answer 12

Acid plus alcohol

Question 13

Fault that can be described as sauerkraut or goat

Answer 13

Lactic acid