Wine Composition and Chemistry

Question 1

t/f: there are various alcohol types present in wine

Answer 1

True

Question 2

main alcohol in wine

Answer 2

ethanol

Question 3

types of alcohol in wine

Answer 3

ethanol (main type)
glycerol
methanol
fusel alcohols aka higher alcohols

Question 4

What happens when you swirl a glass of wine?

Answer 4

you cause the ethanol in the wine to evaporate; ethanol carries the wine’s aromas to the nose

Question 5

Acids typically make up __% to __% of a wine’s volume

Answer 5

0.5 - 0.75 %

Question 6

the prevalent & strongest acid found in wine

Answer 6

tartaric

Question 7

what is a “wine diamond”

Answer 7

crystallized tartaric acid - tartaric acid crystallizes at low temperatures

Question 8

this acid is associated with green apples

Answer 8

malic

Question 9

t/f: citric acid is not a normal component of grapes; it is only found in the winemakers decides to add it

Answer 9

false; naturally found in grape at very, very minuscule levels

Question 10

is acid is found in most types of vinegar

Answer 10

acetic

Question 11

high concentrations of this acid is considered a flaw

Answer 11

acetic

Question 12

this acid is a minor component in grapes + a by-product of fermentation

Answer 12

succinic

Question 13

grape acids

Answer 13

tartaric
malic
citric (trace amounts)
succinic (minor amounts)

Question 14

fermentation acids

Answer 14

lactic
acetic
succinic

Question 15

total acidity vs pH

Answer 15

TA measures the volume of all the acids
pH measures the strength of the acids

Question 16

typical pH range of wine

Answer 16

2.9-3.9

Question 17

lower the pH, the ______ the acid

Answer 17

stronger

Question 18

grapes contain roughly equal amounts of these two sugars

Answer 18

glucose
fructose

Question 19

t/f: grapes contain tiny amounts of unfermentable sugars

Answer 19

true

Question 20

this compound is reponsible for color in red wine

Answer 20

anthocyanin

Question 21

What are phenolics?

Answer 21

various molecules present in wine

Question 22

yellow pigments found in white wine

Answer 22

flavonols

Question 23

t/f: more acidic red wines appear bluer in color

Answer 23

false - redder

Question 24

more acidic wines appear ____ in hue; less acidic wines appear ____

Answer 24

redder / bluer

Question 25

why do wines from sunnier climates tend to have a more golden color?

Answer 25

flavonols - increases in exposure to sunlight

Question 26

what are flavonols responsible for?

Answer 26

yellow pigments in wine

Question 27

why do red wines aged in bottle become less astringent and lighter in color?

Answer 27

over time, tannins and color pigments will polymerize (combine together), eventually becoming too heavy to remain suspended in the liquid and fall as sediment in the wine

Question 28

what is an aldehyde?

Answer 28

oxidized alcohols - formed when wine is exposed to air

Question 29

most common aldehyde

Answer 29

acetaldehyde

Question 30

what is acetaldehyde?

Answer 30

type of aldehyde - formed by the oxidation of ethanol

Question 31

what are esters?

Answer 31

molecules that result from the joining of an acid + an alcohol

Question 32

an acid + an alcohol joining together will form...

Answer 32

esters

Question 33

what are sulfites?

Answer 33

a class of chemicals based on the element sulfur