Level 4 D1 Chap 11 - Wine Components Flashcards
What 2 gases are fundamental to the majority of winemaking?
Oxygen
Sulphur dioxide
What are the compounds that make up wine?
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
What compounds can add sweetness, or a sweet sensation, to a wine?
- Residual sugar
- Alcohol can contribute a sense of sweetness
- Glycerol has a slightly sweet taste
What impact does alcohol have on the taste of wine?
- Adds a sense of sweetness and bitterness.
- Warms the mouth
- Gives the wine body
- May reduce the volatility of aromas
What is a typical wine pH?
3-4 (3 is 10 x more acidic that 4)
What is the typical unit of measure of acid in a wine and what range is normal?
Equivalent g/l of tartaric acid - normally 5.5 - 8.5 g/l
What acid is considered a fault in high concentration?
Acetic acid (vinegar)
Give 2 examples of grape derived aromatic compounds
Methoxypyrazines - grassy/green pepper in Sauvignon Blanc
Rotundone - pepper aroma in Shiraz/ Grüner Veltliner
What is 4MMP?
Aromatic compound released in fermentation that gives box tree aroma to Sauvignon Blanc
It is a thiol.
What are terpenes? Give examples
Aroma compounds formed from precursors during fermentation
From Muscat:
- Linalool (floral)
- Geraniol (rose like)
How are esters derived?
Esters are formed from acid and alcohol, during fermentation
What do esters contribute to a wine?
Fresh and fruity flavours in young wine - e.g. apple/ pineapple
e.g. isoamyl acetate gives aroma of bananas
What aroma compounds originate (ORIGINATE!) from fermentation?
- Esters (fruity, sweet flavours)
- Acetaldehydes (fino sherry)
- Diacetyl (buttery aroma)
- Sulphurous compounds (struck match to rotten eggs)
Give 2 examples of aroma compounds that are not grape or fermentation derived
- Vanillin comes from oak
- Eucalyptol can be absorbed into grape skins from nearby eucalyptus
Name a model for categorising wine aromas, and the key categories that make it up
Vicente Ferreira’s model for wine aromas
- compounds common to all wine
- impact aromas
- contributory aromas
- nonvolatile wine matrix
What range of residual sugar might you fine in different wines?
'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
What are the EU classifications of sweetness in still wine?
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
Where do phenolic compounds come from?
Give two examples of phenolic compounds.
Phenolic compounds come from the skins, seeds and stems
Tannins & Anthocyanins
What are the sources of wine aromatic compounds? (e.g., some are grown, some come from processes, etc.)
- Aromas from grapes
- Aromas created during fermentation from precursors in must
- Aromas created by fermentation
- Aromas from other sources
