Wine Composition

Appears in

Oxford Companion to Wine

Oxford Companion to Wine

By Jancis Robinson

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

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)