CSW 2024

Question 1

5 major chemical components of wine

Answer 1

water
alcohol
acid
sugar
phenolic compounds

Question 2

what % of wine is water

Answer 2

80-90%

Question 3

type of alcohol that results from fermentation

Answer 3

ethyl alcohol or ethanol

Question 4

four other types of alcohol that commonly appear in wine

Answer 4

glycerol
methyl (or methanol)
fusel
higher alcohols

Question 5

what carries aromas of wine to nose

Answer 5

evaporating ethanol

Question 5

what does it mean that ethanol is volatile?

Answer 5

it evaporates easily

Question 5

what caues fine legs or tears?

Answer 5

alcohol

Question 6

what % of wine is acid

Answer 6

0.5% to 0.75%

Question 7

name 6 types of acid commonly found in wine

Answer 7

tartaric
malic
citric
lactic
acetic
succinic

Question 8

what is most common acid in both grape and wine

Answer 8

tarteric

Question 9

which acid in wine can become visibile and in what form

Answer 9

tarteric acid in the form of crystals, known as tartrates or wine diamonds (happens at low temperatures and will not turn back to liquid)

Question 10

which of the six acids is highest in pH

Answer 10

tartaric

Question 11

what is malic acid often associated with (other food)

Answer 11

green apples

Question 12

what types of grapes are most likely to contain malic acid

Answer 12

underripe grapes or cool climate grapes

Question 13

which acid decreases with heat or overripening

Answer 13

malic acid

Question 14

which of the six acids is there the least of in wine and when does it tend to appear

Answer 14

citric acid (naturally it is almost zero in grapes)
usually added by winemaker to make wine more acidic to give balance

Question 15

which acid is not in grapes at all but is in wines? why?

Answer 15

lactic acid. develops in wine because of lactic acid bacteria

Question 16

why does acidity decline with malolactic fermentation

Answer 16

because lactic acid is less acidic than malic acid

Question 17

when is acetic acid introduced to wine

Answer 17

byproduct of fermentation

Question 18

what is the name of the bacteria that causes a chemical reaction between oxygen and ethanol and produces elevated level of acetic acid

Answer 18

acetobacter

Question 19

what characteristic does acetic acid have

Answer 19

very volatile so it evaporates and adds a scent to the wine

Question 20

2 flavors of succinic acid

Answer 20

slightly bitter and salty

Question 21

when is succinic acid introduced to wine

Answer 21

both a minor component of grapes and a by-product of fermentation

Question 22

what are two measurements of acidity in wine and difference of these metrics

Answer 22

Total Acidity (TA): total acid, but some are stronger than others
pH: combined chemical strength of acids present

Question 23

typical range of pH in wine

Answer 23

2.9 to 3.9

Question 24

two reasons winemakers look at pH instead of TA

Answer 24

gives indication of stability plays role in determining sulfur additions

Question 25

what two sugars are in grapes and what is their typical proportions

Answer 25

glucose and fructose usually equal parts

Question 26

what % of the grape is sugar at harvest

Answer 26

between 15% and 28%

Question 27

what is the technical name of glucose and fructose (two names)

Answer 27

monosaccharides or "simple sugars" (they are highly fermentable)

Question 28

why do all wines have some sugar

Answer 28

because all grapes contain a very small amount of unfermentable sugars other than glucose and fructose (so small that undetectable in palate though)

Question 29

besides taste, what are 2 other ways you can detect residual sugars in wine?

Answer 29

by the body/weight/mouthfeel and by the viscosity of wine

Question 30

what % of very sweet wines is sugar

Answer 30

up to 24%