Chapter 1: Wine Composition and Chemistry

Question 1

Five major components of wine

Answer 1

1. Water 2. Alcohol 3. Acid 4. Sugar 5. Phenolic compounds

Question 2

A highly volatile acid, often found in vinegar

Answer 2

Acetic acid

Question 3

The main type of potable alcohol in wine

Answer 3

Ethanol (Ethyl alcohol)

Question 4

Acid reminiscent of green apples

Answer 4

Malic acid

Question 5

The acid most prevalent in both ripe grapes and wine

Answer 5

Tartaric acid

Question 6

Another term for tartrates

Answer 6

Wine diamonds (tartaric acid crystals)

Question 7

Conditions that can lead to a drop in malic acid (in grapes/on the vine)

Answer 7

1. Warm/hot conditions 2. The ripening phase (respiration) 3. Overripe grapes

Question 8

Acid not found in grapes, but often produced during secondary fermentation (mlf)

Answer 8

Lactic acid

Question 9

Acid that is both a minor component of grapes, and a by-product of normal alcoholic fermentation

Answer 9

Succinic acid

Question 10

Typical range of pH for most wines

Answer 10

2.9 to 3.9

Question 11

Two main fermentable sugars found in grapes

Answer 11

Glucose and fructose

Question 12

Sugar remaining in a wine post-fermentation

Answer 12

Residual sugar

Question 13

Compounds that give red wine its color

Answer 13

Anthocyanins

Question 14

Yellow pigments found in white wines

Answer 14

Flavonols (flavones)

Question 15

Sources of tannin

Answer 15

1. Grapes: seeds, stems, skins

2. Wood: oak barrels/other wood products

Question 16

Compound found in red wine known for health benefits

Answer 16

Resveratrol

Question 17

Polymerization

Answer 17

The process by which molecules (such as tannins) transform/combine into longer molecule chains

Question 18

Oxidized alcohols

Answer 18

Aldehydes

Question 19

Molecules that result from the joining of an acid and an alcohol

Answer 19

Esters

Question 20

Chemical reactions resulting from dissolved oxygen

Answer 20

Oxidation

Question 21

In the US, wines containing more than ___ ppm of sulfur dioxide must carry a warning label

Answer 21

10 (ten)