11 - WINE COMPONENTS Flashcards
What are the seven components of wine?
- Water
- Acids
- Alcohol
- Aromatics
- Residual sugars
- Glycerol
- Phenolics
What is the percentage of water in wine?
85% by volume depending on ABV
What kind of alcohol is the most predominant in wine?
Ethanol
What does ethanol contribute to a wine?
Sweetness, bitterness, warmth, body/mouthfeel
What do wines with high alcohol need?
Equally full fruit for balance or they will taste bitter.
What are the two principle acids of wine?
Malic and tartaric
Where do Malic and Tartaric acid come from, and how much of the total acidity of wine do they make up?
The grape itself, 2/3
What is volatile acidity?
Acetic acid. Present in all wine, only a fault when in excess. Smells like vinegar.
What causes the nail polish remover version of volatile acidity?
Acetic acid reacting with ethanol and becoming ethyl acetate
What does acidity contribute to the wine?
Structure, makes wine refreshing. Needs to be in balance with fruit and residual sugar (if applicable)
How is acidity perceived?
In combination with how it’s balanced with residual sugar, and therefore the perception of dryness.
What effect do high levels of Malic acid have?
Be perceived as very firm acidity ( eg difference between cool climate Chard with no malo and Riesling with high tartaric acid)
What is the relationship between TA and pH?
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.
What is the usual range of TA in wine?
Between 5.5 - 8.5 g/L
How is TA expressed?
Total grams per litre of tartaric acid.
What is pH?
Potential for Hydrogen. The measurement for the concentration of effective acidity of a solution.
What is the usual range for pH of wine?
3-4
What are the four benefits of low pH in wine?
- increases microbiological stability
- increases effectiveness of SO2
- Give red wines bright colour
- Enhances ability to age well
What are the four sources of wine aromatics?
- Aromas in the grape
- Aromas from fermentation of aroma precursors
- Aromas from fermentation and its byproducts
- Aromas from other sources
Give two examples of aromas from the grape.
- Mythoxypyrazines (grass/green pepper - SB, CF)
2. Rotundone (pepper - Syrah, GV)
Give two examples of aromas cause by the fermentation of aroma precursors in grape must.
- Thiols (4MMP - passionfruit - SB)
2. Terpenes (linalool - grapey/floral - Muscat)
What are the four aromas that can arise from fermentation and its byproducts?
- Esters - fresh fruity, young wines, reaction of acids and alcohol (ethyl acetate eg)
- Acetaldehyde - oxidation of ethanol. (ethanal) Fino.
- Diacetyl - buttery. Malo.
- Reduction - sulfur compounds - struck match to rotten egg.
Give to examples of aromas from other sources.
- Vanillin - vanilla from new oak ageing
2. Eucalyptol - eucalyuptus leaves volatizing in must but also from trees nearby to vines.
What are the four parts of Vincent Farriera’s model for wine aromas?
- Compounds common to all wines (ethanol, acid etc)
- Impact aromas (specifc, recognisable)
- Contributory aromas (need to combine to be detectable)
- Non-volatile wine matrix (oak etc)
