Wine Chemistry and Faults

Question 1

A highly volatile acid, often found in vinegar

Answer 1

Acetic Acid

Question 2

The main type of potable alcohol found in wine

Answer 2

Ethanol or Ethyl Alcohol

Question 3

The main acid found in grapes and wine

Answer 3

Tartaric Acid

Question 4

The two fermentable sugars found in grapes

Answer 4

Glucose and Fructose

Question 5

Molecules that are formed by the joining of an acid and an alcohol

Answer 5

Esters

Question 6

This wine fault is often described as smelling like “burnt matches”

Answer 6

Sulfur Dioxide

Question 7

This type of molecule often results when wine is exposed to air (oxidized alcohols)

Answer 7

Aldehyde

Question 8

This wine fault often smells like nail polish remover

Answer 8

Ethyl Acetate

Question 9

This substance often makes a wine smell of onions or garlic

Answer 9

Mercaptan

Question 10

This compound is responsible for the red, blue, or purple hue found in red wines

Answer 10

Anthocyanin

Question 11

This acid is likely to crystallize and form “wine diamonds”

Answer 11

Tartaric Acid

Question 12

The common name of the wine fault caused by TCA (2,4,6-trichloranisole)

Answer 12

Cork Taint (corked)

Question 13

The chemical that gives Sherries their unique “oxidized” aroma

Answer 13

Acetaldehyde

Question 14

The most likely cause of a wine that has an unpleasant aroma of Band-Aids, as well as a “sweaty” or “horsey” odor

Answer 14

Brettanomyces (Brett)

Question 15

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

Answer 15

10 (ten)

Question 16

Chemical reactions resulting from dissolved oxygen

Answer 16

Oxidation

Question 17

What is meant by “polymerization”?

Answer 17

When molecules (such as tannins) combine into longer molecule chains.

Question 18

Compound found in red wine known for health benefits

Answer 18

Resveratrol

Question 19

Sources of tannin

Answer 19

Seeds, skins, and stems of grapes

Oak barrels/other oak products

Question 20

Yellow pigments found in white wines

Answer 20

Flavonols

Question 21

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

Answer 21

Succinic acid

Question 22

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

Answer 22

Lactic acid

Question 23

Conditions that can lead to a drop in malic acid

Answer 23

Warm/hot climate, the ripening phase, over-ripe grapes, MLF

Question 24

Another term for tartrates

Answer 24

Wine diamonds (tartaric acid crystals)

Question 25

An acid that tastes like green apples

Answer 25

Malic acid

Question 26

5 major components in wine

Answer 26

Water, alcohol, acid, sugar, phenolic compounds

Question 27

Conditions that lack oxygen

Answer 27

Reductive

Question 28

Fault caused by the improper breakdown of sorbic acid

Answer 28

Geranium fault

Question 29

Term used for a “cooked” or “baked” aroma

Answer 29

Maderized

Question 30

Bacteria that can turn wine into vinegar

Answer 30

Acetobacter

Question 31

Smells like rancid butter

Answer 31

Butyric acid

Question 32

Wine fault described as smelling like “rotten eggs”

Answer 32

Hydrogen sulfide

Question 33

Wine fault described as smelling like burnt matches

Answer 33

Sulfur dioxide