Wine Composition and Chemistry

Question 1

The most prevalent of the acids found in grapes and wine

Answer 1

Tartaric Acid

Question 2

The component that makes up 80%-90% of the volume of most wines

Answer 2

Water

Question 3

Slow moving “tears” that may appear in a wine glass after the wine is swirled

Answer 3

Legs

Question 4

Has little or no sensory impact on the major of quality wine

Answer 4

Citric Acid

Question 5

The component that makes up 10-15% of the volume of most wines

Answer 5

Ethyl Alcohol

Question 6

A type of secondary alcohol

Answer 6

Glycerol

Question 7

A sharp tasting acid often associated with green apples

Answer 7

Malic Acid

Question 8

An acid produced via the conversation of malic acid

Answer 8

Lactic Acid

Question 9

An acid with a slightly bitter, slightly salty flavor

Answer 9

Succinic Acid

Question 10

The acid found in most types of vinegar

Answer 10

Acetic Acid

Question 11

Of the six main acids found in wine, list those that are typically found in unfermented grapes

Answer 11

Tartaric, Malic, Citric and Succinic Acid

Question 12

Of the acids typically found in grapes, which are found in very small quantities?

Answer 12

Citric and Succinic Acid

Question 13

Which acid is known to cause deposits known as wine diamonds?

Answer 13

Tartaric Acid

Question 14

What is the name of the winemaking process that, in add-on to changing a wine’s acid components, often provides wines with a creamy texture and a buttery aroma?

Answer 14

Malolactic Fermentation

Question 15

What measurement is used to define the volume of all the acids present in a wine?

Answer 15

Total Acidity

Question 16

What does pH measure?

Answer 16

Combined chemical strength of the acids present

Question 17

What is a typical pH measurement of a highly acidic wine?

Answer 17

2.9 (Lower the # the more acidic)

Question 18

What pH measurement would you expect to find in a low acid wine?

Answer 18

3.9 (Higher the # the less acidic)

Question 19

What are the two main fermentable sugars found in wine grapes?

Answer 19

Glucose/Fructose

Question 20

What term is used to describe a wine that does not contain any detectable sugar?

Answer 20

Dry

Question 21

Yellow pigments found in white wine

Answer 21

Flavonols

Question 22

An aromatic compound found in oak barrels

Answer 22

Vanillin

Question 23

A compound found in wine believed to be beneficial to human health

Answer 23

Resveratol

Question 24

One of the most common esters found in wine

Answer 24

Ethyl acetate

Question 25

The specific component that gives fino Sherries their distinctive aroma

Answer 25

Acetaldehyde

Question 26

The compounds that give red wine its red, blue or purple hue

Answer 26

Anthocyanins

Question 27

Bitter compounds found in the skins, seeds, and stems of grapes

Answer 27

Tannins

Question 28

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

Answer 28

Esters

Question 29

Matter sometimes formed as a result of polymerization

Answer 29

Sediment

Question 30

A preservative widely used in winemaking

Answer 30

Sulfur

Question 31

Oxidized alcohols formed when wine is exposed to air

Answer 31

Aldehydes

Question 32

Promotes the release of the wine's aromatic compounds

Answer 32

Carbon dioxide

Question 33

(True or False) Red wines that are highly acidic tend to appear more blue in color, whereas low-acid red wines appear more red.

Answer 33

False -

Question 34

(True or False) Tannins can create a textural, drying sensation on the palate.

Answer 34

True

Question 35

(True or False) Madeira is an example of a wine that is produced in such a way that oxidation is encouraged and expected

Answer 35

True

Question 36

(True or False) Flavonols increase in white grapes with increased exposure to sunlight

Answer 36

Ture

Question 37

(True or False) Raw (untoasted) oak barrels will typically contain higher levels of vanillin than lightly toasted barrels

Answer 37

False - light to medium toasted barrels will bring out more vanillin compounds. However, high toasting will result in less vanillin compounds

Question 38

(True or False) The phenolic compounds of a grape are concentrated primarily in its skin and seeds

Answer 38

True

Question 39

(True or False) Wines may become oxidized after being exposed to heat

Answer 39

True

Question 40

(True or False) It is common for winemakers to encourage the oxidation of white wines such as Chenin Blanc and Riesling by maximizing air exposure during the preliminary stages of fermentation and aging

Answer 40

False -

Question 41

(True or False) Ethyl acetate imparts an aroma similar to nail polish remover or glue at very low concentrations, whereas at higher concentrations it tends to smell of dried rose petals or perfume

Answer 41

False

Question 42

(True or False) Esters represent the largest group of odiferous compounds found in wine

Answer 42

True

Question 43

(True or False) In the United States, any wine containing more than 2 ppm of sulfur dioxide is required to display the "contains sulfites" warning on the label

Answer 43

False - wines containing more than 10 ppm must have a warning label

Question 44

(True or False) Normal fermentation does not produce enough carbon dioxide to make a difference in the flavor profile of a typical table wine

Answer 44

False

Question 45

What is the most prevalent type of acid found in both vinifera grapes and wine?

Answer 45

Tartaric Acid

Question 46

What phenolic compound is responsible for the bitter taste and drying textural sensation found in many red wines?

Answer 46

Tannin

Question 47

What is a type of molecule that results from the joining of an acid and an alcohol?

Answer 47

Esters

Question 48

What is the typical pH range found in table wines?

Answer 48

2.9 - 3.9

Question 49

What is a wine diamond?

Answer 49

A small particle created via the crystallization of tartaric acid

Question 50

What is methyl alcohol?

Answer 50

A secondary alcohol produced via fermentation

Question 51

In the United States, wine with more than 10 ppm of what compound must have a warning label?

Answer 51

Sulfites

Question 52

What compound gives red wines their red, blue or purple hues?

Answer 52

Anthocyanins

Question 53

What acid is created in small amounts during typical fermentation, is found in many types of vinegar?

Answer 53

Acetic acid

Question 54

Two main fermentable sugars present in wine grapes are:

Answer 54

Glucose and Fructose; also known as monosaccharides

Question 55

The 5 major components of wine

Answer 55

Water, alcohol, acid, sugar and phenolics

Question 56

The 3 possible/rare components of wine

Answer 56

Bacteria, yeast and protein

Question 57

Secondary alcohols include:

Answer 57

Glycerol, methanol and fusel alcohols

Question 58

Slower, thicker tears indicate:

Answer 58

Higher alcohol

Question 59

Two ways to measure acidity

Answer 59

TA and pH

Question 60

Terms used to describe acidity

Answer 60

Soft, smooth, fresh, crisp, lively and tart

Question 61

Often used in acidification and is the strongest in pH

Answer 61

Tartaric Acid

Question 62

Sometimes used to increase the TA (total acidity)

Answer 62

Citric Acid

Question 63

Created in wine via a bacteria, as a by-product of MLF

Answer 63

Lactic Acid

Question 64

Which acid is volatile (evaporates easily)

Answer 64

Acetic acid

Question 65

Easily reacts to form esters

Answer 65

Succinic acid

Question 66

Typical sweetness range

Answer 66

~.8% - 24%

Question 67

Five phenolics

Answer 67

``` Anthocyanins Flavonols Tannin Vanillin Reservatrol ```

Question 68

Four additional components of wine

Answer 68

Aldeydes Esters Dissolved gasses Sulfites