Wine Composition

Appears in

Published 2006

About

wine composition, differs quite considerably from grape composition, partly because parts of the grape are discarded during winemaking, and partly because the processes involved effect a complicated series of transformations. Alcoholic fermentation, for example, transforms sugars into alcohol, while malolactic conversion reduces the level of malic acid in favour of lactic acid. The precise composition of a wine varies with wine type, harvest conditions and date, vintage characteristics, and the age of the wine (see ageing for details of how wine composition may change with age). Nevertheless, the table gives some guidance as to the likely range of concentrations of the essential constituents of the approximately 1,000 so far identified.

Wine composition

Component	Proportions per l	Comments
Dissolved gases
carbon dioxide	0–50 cc
sulfur dioxide
Total	80–200 g	More in some sweet wines
Free	10–50 mg	More in some unstable wines
Volatile substances
water	700–900 g
ethanol (alcohol)	8.5–15% by vol	More in fortified, less in low-alcohol wines
higher alcohols	0.15–0.5 g
acetaldehyde	0.005–0.5 g	Higher amounts in sherry and similar wines
esters	0.1–0.3 g
acetic acid	0.35–0.6 g
Fixed substances
residual sugar	0.8–180 g}	According to type of wine; more in sweet and botrytized wines
glycerol	5–12 g
phenolics	0.2–0.5 g; 1.5–4.0 g	Lower range for white wines, higher range for reds
Organic acids
tartaric acid	3–10 g	Depending on grape origin
malic acid	0–4 g}	According to climate and extent of malolactic conversion
lactic acid	0–1 g	According to climate and extent of malolactic conversion
succinic acid	0.2–1.5 g
citric acid	0–1 g	Found in wines where additions have been made
Mineral salts
Sulfates	0.1–0.4 g}	Expressed as potassium salts
Chlorides	0.25–0.85 g
Phosphates	0.08–0.5 g
Mineral elements
potassium	0.7–1.5 g
calcium	0.06–0.9 g
iron	0.002–0.006 g

Based on Navarre, C., L’Oenologie (7th edn, Paris, 2010)