D1 Wine components

Question 1

Wine components

Answer 1

• Water (approx. 85%)
• RS residual sugar
• Acids (typically 5.5-8.5 g/L)
• Phenolics (anthocyanins and tannins)
• Aromatics
• Alcohol
• Glycerol

Question 2

Sugar - EU classification of Sweetness level

Answer 2

The classification for still wines take into account:
- level of residual sugar
- optionally higher level of residual sugar with higher total acidity

1. Dry/sec/trocken.
   Up to 4 g/L RS.
   or not exceeding 9 g/L if total acidity is not more than 2g below RS content.
2. Medium dry/demi-sec/halbtrocken.
   Between 4 g/L RS and 12 g/L RS.
   or not exceeding 18 g/L RS if total acidity is not more than 10g below RS content.
3. Medium or medium sweet/molleux/lieblich.
   Between 12 g/L and 45 g/L.
4. Sweet/doux/suss
   More than 45 g/L.

Question 3

Acids

Answer 3

Acidity makes the wine taste refreshing, and should be balance with fruit concentration and residual sugar.

• Tartaric and Malic acids comes from the grapes.
• Lactic and acetic are produced in malolactic conversion or fermentation.
• Volatile acidity refers to acetic acid (vinegar smell), when react with alcohol becomes ethyl acetate (nail varnish remover smell).

Total acidity is measured by g/L in tartaric acid.

pH is a scale of measurement for the concentration of the effective acidity in a solution. (typically 3-4, inverse scale)
A low pH:
- increases the microbiological stability
- increase effectiveness of SO2
- gives red wine a bright colour
- enhances a wine’s ability to age well

Question 4

Phenolics

Answer 4

Include anthocyanin and tannins.

Contribute to structure and balance of the wine.
Tannins binds with proteins in the mouth, giving a drying sensation on the palate.

Question 5

Aromatics

Answer 5

Wine aromatics may comes from:

1. Compounds in Grapes
   - Mathoxypyrazines (grassy, green pepper)
   - Rotundone (Pepper aroma)
2. Compounds in grapes that become precursors (aromatic) during fermentation
   - Thiols (box tree aroma)
   - Terpenes (fruiti, floral aroma)
   - Linalool and geraniol (grapey aromas)
3. From fermentation and its products
   - Easter (fresh, fruity aroma) created by the action of yeast.
   - Easter Isoamyl acetate (banana, pineapple)
   - Acetaldehyde (stale smell) (fino sherry) occurs due to oxidation of ethanol.
   - Diacetyl (buttery aroma) produced during malolactic conversion.
   - Yeast can produce reductive sulfur compounds during fermentation and lees ageing (struck match, rotten egg)
4. Other sources
   - Oak barrel (vanillin)
   - Eucalyptol near vineyards

Question 6

Alcohol

Answer 6

Ethanol forms during fermentation.

Contributes to a sense of oral warmth, fullness of the body and mouthfeel.

High alcohol level may reduce aromas perception, therefore alcohol level must balance the fruit concentration.

Question 7

Glycerol

Answer 7

Is derived from sugar in grapes.
It is higher in botrytis wines and carbonic maceration made wines.

Contributes to smoothness to the texture and fullness of the body.

It has a slight sweet taste.