Chapter 1: Wine Composition and Chemistry

Question 1

What are the main components of wine?

Answer 1

Water, alcohol, acid, sugar, and phenolic compounds.

Question 2

What are the approximate concentrations of the major components of wine?

Answer 2

Water - 80 - 90 %
Alcohol - 10-15 %
Acid - 0.5 - 0.75 %
Sugar - 0 - 24 % (generally dry = 0 %)
Phenolic Compounds - minute quantities)

Question 3

What are the primary types of alcohol in wine?

Answer 3

Ethyl alcohol (primary), glycerol, methyl alcohol, and fusel alcohols.

Question 4

What are the primary types of acids in wine?

Answer 4

GRAPE ACIDS
Tartaric Acid
Malic Acid
(Citric Acid) (minute, but also added)
(Succinate Acid) (minute, also created during fermentation)

FERMENTATION ACIDS
Lactic (created through malolactic fermentation)
Acetic Acid
Succinic Acid

Question 5

What are the primary types of sugars in wine?

Answer 5

Glucose

Fructose

Question 6

What is the range for acidity in wine?

Answer 6

2.9 to 3.9 pH, with lower indicating stronger acid content.

Question 7

What are anthocyanins?

Answer 7

Phenolic compound that gives red wine its color. Ranges from blue to purple to red. Acidity also affects color, with more acid tending to red and less acid to blue.

Question 8

What are flavonols?

Answer 8

Phenolic compound that give yellow color to white wines. Flavonols increase with increased exposure to sunlight. Therefore more sun exposure equals more golden color.

Question 9

What are tannins?

Answer 9

Astringent, bitter phenolic compounds found in the skins, seeds, and stems of grapes. A natural preservative.

Question 10

What is vanillin?

Answer 10

Vanillin is an aromatic phenolic compound found in oak that imparts a vanilla scent to barrel aged wines.

Question 11

What are resveratrol?

Answer 11

Resveratrol is a compound believed to have several health benefits.