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What's in the wine?
The ingredients of wine influence sensory perception.
For the most part, wine consists of Waterusually between 78 and 85 per cent.
The second largest part is made up of Alcohol (mainly ethanol and glycerine). To convert: one percent alcohol by volume corresponds to about eight grams of alcohol per litre of wine. For fermentation, the rule of thumb is that one percent by volume (or 7.9 grams) of alcohol per litre of wine is produced from around 15 grams of sugar per litre of must (or vice versa: 10 g/l sugar ≈ 5.2 g/l alcohol ≈ 0.66 percent alcohol by volume).
Another essential ingredient is Sugar - the residual sugar that has not been converted into alcohol (ethanol) and carbon dioxide during fermentation. The main types of sugar in wine are fructose and glucose, with the glucose being fermented first; the residual sugar therefore usually has a higher fructose content. The residual sugar content can range from zero to over 250, and in rare cases even over 300 grams per litre of wine.
Acidity is also an important component of wine, with the acid content being composed of several different types of acid: primarily malic acid, tartaric acid, lactic acid and citric acid, as well as traces of other acids. During malolactic fermentation (also called biological acid degradation), the strong malic acid is converted by bacteria into the weaker lactic acid.
In addition - and this is particularly important for sensory perception apart from sugar and acidity - wine contains Colouring, Flavourings and Tannins. Chemically, these include phenols, esters, thiols, terpenes, pyrazines and tannins. These sometimes highly complex compounds shape the smell, taste and texture as well as, to some extent, the appearance of the wine.
Finally, minerals are relevant: mostly salts - especially of potassium, phosphorus, calcium, magnesium and sodium - as well as trace elements.