Wine composition and chemistry

Question 1

What are the major components of wine

Answer 1

Water, Alcohol, Sugar, Acid & Phenolic compound

Question 2

What compound is present in wine by extensive ageing or contact with Lees

Answer 2

Yeast or proteins

Question 3

where does the water in wine come from & what is the % of water present in wine

Answer 3

Water comes from grapes and the wine consists of 80-90% water

Question 4

What is the most prevalent ingredient in wine after water

Answer 4

Alcohol

Question 5

How much % of alcohol is present in wine

Answer 5

10-15%

Question 6

What is the primary alcohol in wine and name other alcohol present in wines

Answer 6

Primary alcohol is Ethyl alcohol(ethanol)

Other alcohol- glycerol, methyl alcohol, fusel alcohol

Question 7

What does the term volatile mean

Answer 7

A substance that evaporates easily

Question 8

Wines with higher alcohol are heavier than wines with low alcohol. True or False

Answer 8

True

Question 9

What are wine legs

Answer 9

Tears of wine that form on the edge of the glass when swirled, result of high level alcohol in wine

Question 10

How does acid help white wine

Answer 10

It gives wines its structure, balance and thirst quenching refreshment

Question 11

Acids make up _____ % of a wines volume

Answer 11

0.5-0.75%

Question 12

Name all the acids present in wine

Answer 12

Tartaric, malic, citric, lactic, acetic, succinic

Question 13

Name the fermentation acids

Answer 13

Lactic, succinic, acetic

Question 14

Acid with sharp, slightly bitter and salty flavor

Answer 14

Succinic

Question 15

Acid associated with green apples

Answer 15

Malic

Question 16

Level of malic acid reduces as the grape ripens.True or False

Answer 16

True

Question 17

What acid requires special equipment to measure and is not a normal component of wine

Answer 17

Citric

Question 18

Premium wines have citric acid added to increase TA. True or False

Answer 18

False

Question 19

Which bacteria is responsible for MLF in winemaking

Answer 19

Lactic acid bacteria

Question 20

Define MLF

Answer 20

A process in winemaking in which malic acid is converted to softer-tasting lactic acid

Question 21

MLF gives the wines its _____

Answer 21

Creamy texture and a buttery aroma

Question 22

______ is found in vinegar and is also a created during fermentation

Answer 22

Acetic acid

Question 23

higher concentrations of acetic acid lead to

Answer 23

chemical reaction between ethanol and oxygen

Question 24

Name the grape acids

Answer 24

Tartaric, malic, citric and succinic

Question 25

What is total acidity(TA)

Answer 25

Total volume of all acids present in wine

Question 26

What is pH

Answer 26

Combined chemical strength of all acids

Question 27

in terms of pH, wines usually measure between

Answer 27

2.9-3.9

Question 28

Wine with pH 3.4 will be more acidic than wine with pH 2.9 | True of False

Answer 28

False

Question 29

During harvest, grapes contain ______ amount of sugar

Answer 29

15-28%

Question 30

What are the 2 forms of sugars present in grape

Answer 30

Glucose & Fructose

Question 31

Can dry wines contain trace amount of sugar

Answer 31

yes

Question 32

Residual sugar in wine adds to what

Answer 32

weight or body

Question 33

Dessert wines can contain upto ____ % of residual sugar

Answer 33

24%

Question 34

What are phenolic compounds

Answer 34

A large category of various molecules present in many wine

Question 35

Minute quantities of phenolics in wine can have a major impact on sensory profile of wine. True or False

Answer 35

True

Question 36

Name all the Phenolic compounds

Answer 36

Anthocyanins, Flavonols, Tannins, Vanillin, Resveratrol

Question 37

Name other molecules/components present in wine

Answer 37

Aldehydes, Esters, Dissolved gases, Sulfites

Question 38

Compound that gives red wine its colour

Answer 38

Anthocyanin

Question 39

Compound that gives white wines its colour

Answer 39

Flavonols

Question 40

_____ is a compound present in red wines and is a backbone for big red wines

Answer 40

Tannin

Question 41

Compound responsible for the vanilla scent in barrel aged wines

Answer 41

Vanillin

Question 42

Compound known to have health benefits

Answer 42

Resveratrol

Question 43

What are aldehydes

Answer 43

Oxidized alcohols formed when the when the wine is exposed to air

Question 44

Which styles of wine encourage formation of aldehydes in their winemaking technique

Answer 44

Sherry & Madeira

Question 45

What is acetaldehyde

Answer 45

Most common aldehyde formed by the oxidation of ethanol

Question 46

What are esters

Answer 46

They are molecules that result from joining of an acid and alcohol

Question 47

What is the ester of acetic acid and ethanol known

Answer 47

Ethyl acetate

Question 48

Higher quantities of ethyl acetate impart faulty aromas of

Answer 48

nail polish remover, varnish or glue

Question 49

low quantities of ethyl acetate impart aromas of

Answer 49

fruity and floral aromas

Question 50

what helps remove molecules of oxygen from wine

Answer 50

Sulfur

Question 51

What does dissolved oxygen do in wine

Answer 51

Dissolved oxygen promotes oxidation

Question 52

How does CO2 help wine

Answer 52

CO2 keeps wine fresh and lively, promoting release of aromatic compounds

Question 53

Why is sulfur added in wines

Answer 53

It is an important preservative used to keep wines stable after fermentation. It is an antioxidant and anti bacterial agent

Question 54

When do the winemakers need to add "Contains Sulfites" on their label

Answer 54

When the content is more than 10 parts per million(ppm)