CSW Prep - Wine Composition and Chemistry

Question 1

What are the major categories of chemicals found in wine?

Answer 1

Water
Alcohol
Acid
Sugar
Phenolic Compounds

Question 2

The acronym WAASP is helpful to remember what?

Answer 2

The major chemicals found in wine. Water, Alcohol, Acid, Sugar, Phenolic Compounds

Question 3

What is important to know about water?

Answer 3

Makes up 80-90% of wine.

Question 4

How much of wine is made of water?

Answer 4

80-90%, typically from the grapes themselves.

Question 5

Why would winemakers add water to wine?

Answer 5

Intentionally dilute if alcohol or phenolic compounds beyond desired levels.

Question 6

What is the primary compound in wine?

Answer 6

Water

Question 7

What is the second major compound in wine?

Answer 7

Alcohol

Question 8

What is the approximate amount of alcohol commonly found in wine?

Answer 8

10-15%

Question 9

What are the most common kinds of alcohol found in wine?

Answer 9

Ethyl Alcohol (Ethanol)
Glycerol
Methyl Alcohol (Methanol)
Fusil Oils (Higher Alcohols

Question 10

What is the most common kind of alcohol found in wine?

Answer 10

Ethanol.

Question 11

What is the result of fermentation (Yeast + Sugar = ?)?

Answer 11

Ethanol (Alcohol)

Question 12

What is the intoxicating element in wine?

Answer 12

Ethanol.

Question 13

True or False: Ethanol is a volatile compound?

Answer 13

True. meaning that it evaporates easily.

Question 14

What is a volatile organic compound?

Answer 14

Organic chemicals that have high vapor pressure at ordinary room temperature.

Question 15

What is the subjective reference for alcohol level?

Answer 15

“Body.” Light body wines tend to have less alcohol.

Question 16

What is the key component that differentiates wine from other forms of alcohol?

Answer 16

Acid.

Question 17

What type of is most reliant on acid for flavor structure?

Answer 17

White Wine.

Question 18

What are the principle acids in wine?

Answer 18

Tartaric Acid
Malic Acird
Lactic Acid
Acetic Acid 
Succinic Acid
Citric Acid
(CLAMS T)

Question 19

What is tactic acid?

Answer 19

White crystalline diprotic acid. It has the propensity to form tactic crystals (yes cream of tartar) at low temperatures.

Question 20

What happens when tactic crystals form?

Answer 20

Crystals will not redissolve into the wine and wine will be noticeably less acidic.

Question 21

What is malic acid?

Answer 21

Dicarboxylic acid, made by all living organisms, contributes to pleasantly sour taste in fruits.

Associated with green apples.

Question 22

Where is the most common source of malic acid?

Answer 22

Underripe grapes (think green apple).

Question 23

What types of wines a least like to have high malic acid?

Answer 23

Wine made from grapes grown in hot, warm climates, where grapes ripen easily. Malic acid commonly found in underripe grapes.

Question 24

What is lactic acid?

Answer 24

Acid not found naturally in grapes but created by lactic bacteria. Lactic bacteria convert malic acid into lactic acid.

Question 25

What is malolactic fermentation?

Answer 25

Process in winemaking where tart-tasting malic acid, naturally present in grapes, is converted to softer-tasting lactic acid.

Question 26

Which is less intense: Lactic acid or malic acid?

Answer 26

Lactic acid. But it is not found naturally in grapes, it is created by malolactic fermentation.

Question 27

Which is found naturally in grapes: Malic Acid or Lactic Acid?

Answer 27

Malic acid.

Question 28

What is acetic acid?

Answer 28

Acid of vinegar.

Question 29

What is the most volatile type of acid commonly found in wine?

Answer 29

Acetic acid, readily joins the aromas of wine.

Question 30

What are the two numbers used to describe the acidity of wine?

Answer 30

(1) Total Acidity (TA), and (2) pH

Question 31

What is total acidity (TA)?

Answer 31

Volume of all acids found in wine.

Question 32

What does pH calculate?

Answer 32

Calculates the combined STRENGTH of acids presenting wine. The lower the pH, the stronger the acids.

Question 33

What is the typical range for acidity strength in wine?

Answer 33

2.9 and 3.8 on pH scale.

Question 34

What is Succinic acid?

Answer 34

Acid found in wine and common by-product of normal alcohol fermentation.

Question 35

How is citric acid sometimes found in wine?

Answer 35

Added to increase total acidity, as it is not commonly found in grapes.

Question 36

How much sugar is typically found in grapes?

Answer 36

15-28 percent sugar at harvest.

Question 37

What are the two types of sugar commonly found in grapes?

Answer 37

Glucose and Fructose.

Question 38

What converts sugar to alcohol?

Answer 38

Yeast.

Question 39

What is the average recognition threshold for sugar?

Answer 39

Around 1%

Question 40

What are the most important compounds in wine concerning the chemical construction/destruction process?

Answer 40

Carbohydrates, or compounds containing carbon, hydrogen and oxygen.

Question 41

What are other common terms for phenolic compounds?

Answer 41

Phenolics, polyphenolics, or polyphenols.

Question 42

What are anthocyanins?

Answer 42

Phenolic compounds. Give wine blue, purple or red color. Change with acidity level, redder in more acidic wines and blue in less acidic ones.

Question 43

If a wine is more blue, it may be an indicator of what AND due to what compound?

Answer 43

Indicates that wine may be less acidic, due to phenolic compound - Anthocyanins.

Question 44

Name three commonly phenolics found in wine.

Answer 44

``` Anthocyanins Flavones Tannins Vanillin Resveratol ```

Question 45

What are flavones?

Answer 45

Yellow pigments found in white wine.

Question 46

What are tannins?

Answer 46

Astringent or bitter compounds found in skin, seeds or stems that form the backbone to wine structure of big red wines. Also prevent oxidation.

Question 47

What compounds commonly helps prevent oxidation in red wines?

Answer 47

Tannin

Question 48

What is vanillin?

Answer 48

Phenolic compound. Aromatic compound in oak that imparts vanilla odor.

Question 49

What is resveratol?

Answer 49

Phenolic compound believed to have beneficial health effects.

Question 50

What are aldehydes?

Answer 50

Less common phenolic compound, formed when wine is exposed to air. Commonly used in making sherry or maderia.

Question 51

What are esters?

Answer 51

Molecules result from joining acid and alcohol. Largest group of odiferous compounds in wine.

Question 52

What are the most common dissolved gases found in wine?

Answer 52

Oxygen and carbon dioxide.

Question 53

What is common problem associated with presence of dissolved oxygen?

Answer 53

Oxidation.

Question 54

What are sulfites.

Answer 54

Less common phenolic compound. Importance preservative.

Question 55

What phenolic compound is commonly associated with preservation?

Answer 55

Sulfites. Some people sensitive, so wines destined for US with more than 10 parts per million (ppm) of sulfur dioxide required to place warning on label.