11 - WINE COMPONENTS

Question 1

What are the seven components of wine?

Answer 1

1. Water
2. Acids
3. Alcohol
4. Aromatics
5. Residual sugars
6. Glycerol
7. Phenolics

Question 2

What is the percentage of water in wine?

Answer 2

85% by volume depending on ABV

Question 3

What kind of alcohol is the most predominant in wine?

Answer 3

Ethanol

Question 4

What does ethanol contribute to a wine?

Answer 4

Sweetness, bitterness, warmth, body/mouthfeel

Question 5

What do wines with high alcohol need?

Answer 5

Equally full fruit for balance or they will taste bitter.

Question 6

What are the two principle acids of wine?

Answer 6

Malic and tartaric

Question 7

Where do Malic and Tartaric acid come from, and how much of the total acidity of wine do they make up?

Answer 7

The grape itself, 2/3

Question 8

What is volatile acidity?

Answer 8

Acetic acid. Present in all wine, only a fault when in excess. Smells like vinegar.

Question 9

What causes the nail polish remover version of volatile acidity?

Answer 9

Acetic acid reacting with ethanol and becoming ethyl acetate

Question 10

What does acidity contribute to the wine?

Answer 10

Structure, makes wine refreshing. Needs to be in balance with fruit and residual sugar (if applicable)

Question 11

How is acidity perceived?

Answer 11

In combination with how it’s balanced with residual sugar, and therefore the perception of dryness.

Question 12

What effect do high levels of Malic acid have?

Answer 12

Be perceived as very firm acidity ( eg difference between cool climate Chard with no malo and Riesling with high tartaric acid)

Question 13

What is the relationship between TA and pH?

Answer 13

Linked but not correlated. Due to buffering effects of other molecules. Wines with high TA would usually have a low pH, but the numbers are not directly related.

Question 14

What is the usual range of TA in wine?

Answer 14

Between 5.5 - 8.5 g/L

Question 15

How is TA expressed?

Answer 15

Total grams per litre of tartaric acid.

Question 16

What is pH?

Answer 16

Potential for Hydrogen. The measurement for the concentration of effective acidity of a solution.

Question 17

What is the usual range for pH of wine?

Answer 17

3-4

Question 18

What are the four benefits of low pH in wine?

Answer 18

1. increases microbiological stability
2. increases effectiveness of SO2
3. Give red wines bright colour
4. Enhances ability to age well

Question 19

What are the four sources of wine aromatics?

Answer 19

1. Aromas in the grape
2. Aromas from fermentation of aroma precursors
3. Aromas from fermentation and its byproducts
4. Aromas from other sources

Question 20

Give two examples of aromas from the grape.

Answer 20

1. Mythoxypyrazines (grass/green pepper - SB, CF)

2. Rotundone (pepper - Syrah, GV)

Question 21

Give two examples of aromas cause by the fermentation of aroma precursors in grape must.

Answer 21

1. Thiols (4MMP - passionfruit - SB)

2. Terpenes (linalool - grapey/floral - Muscat)

Question 22

What are the four aromas that can arise from fermentation and its byproducts?

Answer 22

1. Esters - fresh fruity, young wines, reaction of acids and alcohol (ethyl acetate eg)
2. Acetaldehyde - oxidation of ethanol. (ethanal) Fino.
3. Diacetyl - buttery. Malo.
4. Reduction - sulfur compounds - struck match to rotten egg.

Question 23

Give to examples of aromas from other sources.

Answer 23

1. Vanillin - vanilla from new oak ageing

2. Eucalyptol - eucalyuptus leaves volatizing in must but also from trees nearby to vines.

Question 24

What are the four parts of Vincent Farriera’s model for wine aromas?

Answer 24

1. Compounds common to all wines (ethanol, acid etc)
2. Impact aromas (specifc, recognisable)
3. Contributory aromas (need to combine to be detectable)
4. Non-volatile wine matrix (oak etc)