Level 4 D1 Chap 11 - Wine Components

Question 1

What 2 gases are fundamental to the majority of winemaking?

Answer 1

Oxygen

Sulphur dioxide

Question 2

What are the compounds that make up wine?

Answer 2

1 Water is about 85%
2 Alcohol
3 Glycerol
4 Acids:  tartaric and malic, smaller amounts of lactic and acetic
5 Wine aromatics
6 Residual sugar
7 Phenolics

Question 3

What compounds can add sweetness, or a sweet sensation, to a wine?

Answer 3

• Residual sugar
• Alcohol can contribute a sense of sweetness
• Glycerol has a slightly sweet taste

Question 4

What impact does alcohol have on the taste of wine?

Answer 4

• Adds a sense of sweetness and bitterness.
• Warms the mouth
• Gives the wine body
• May reduce the volatility of aromas

Question 5

What is a typical wine pH?

Answer 5

3-4 (3 is 10 x more acidic that 4)

Question 6

What is the typical unit of measure of acid in a wine and what range is normal?

Answer 6

Equivalent g/l of tartaric acid - normally 5.5 - 8.5 g/l

Question 7

What acid is considered a fault in high concentration?

Answer 7

Acetic acid (vinegar)

Question 8

Give 2 examples of grape derived aromatic compounds

Answer 8

Methoxypyrazines - grassy/green pepper in Sauvignon Blanc

Rotundone - pepper aroma in Shiraz/ Grüner Veltliner

Question 9

What is 4MMP?

Answer 9

Aromatic compound released in fermentation that gives box tree aroma to Sauvignon Blanc

It is a thiol.

Question 10

What are terpenes? Give examples

Answer 10

Aroma compounds formed from precursors during fermentation

From Muscat:

• Linalool (floral)
• Geraniol (rose like)

Question 11

How are esters derived?

Answer 11

Esters are formed from acid and alcohol, during fermentation

Question 12

What do esters contribute to a wine?

Answer 12

Fresh and fruity flavours in young wine - e.g. apple/ pineapple

e.g. isoamyl acetate gives aroma of bananas

Question 13

What aroma compounds originate (ORIGINATE!) from fermentation?

Answer 13

• Esters (fruity, sweet flavours)
• Acetaldehydes (fino sherry)
• Diacetyl (buttery aroma)
• Sulphurous compounds (struck match to rotten eggs)

Question 14

Give 2 examples of aroma compounds that are not grape or fermentation derived

Answer 14

• Vanillin comes from oak

- Eucalyptol can be absorbed into grape skins from nearby eucalyptus

Question 15

Name a model for categorising wine aromas, and the key categories that make it up

Answer 15

Vicente Ferreira’s model for wine aromas

• compounds common to all wine
• impact aromas
• contributory aromas
• nonvolatile wine matrix

Question 16

What range of residual sugar might you fine in different wines?

Answer 16

'Brut nature' sparkling - 0-1g/l
Dry wine:  2-3g/l
Port: 35-120 g/l
Sweet wine: Sauternes  150 g/l
Sweet wine: Pedro Ximenez 400 g/l

Question 17

What are the EU classifications of sweetness in still wine?

Answer 17

Dry/sec/trocken: up to 4 g/l, or up to 9g/l if acid is not more than 2 g/l less

Medium dry/ demi-sec/ halbtrocken: 4-12 g/l, or up to 18 g/l if acid is not more than 10 g/l less

Medium sweet/ moelleux/ lieblich: 12-45 g/l

Sweet: 45 g/l or more

Question 18

Where do phenolic compounds come from?

Give two examples of phenolic compounds.

Answer 18

Phenolic compounds come from the skins, seeds and stems

Tannins & Anthocyanins

Question 19

What are the sources of wine aromatic compounds? (e.g., some are grown, some come from processes, etc.)

Answer 19

• Aromas from grapes
• Aromas created during fermentation from precursors in must
• Aromas created by fermentation
• Aromas from other sources