Pigments

pigments, inclusive name for the compounds which impart colour. Colour results from the presence in these compounds of structures or functional groups that absorb light of particular wavelengths. Young red wines get their colour from the anthocyanins and pigmented tannins, with the former decreasing in concentration and the latter reciprocally increasing and making the dominant contribution to colour as the wine ages. In contrast to the broad understanding of the pigments (and their chromophores) responsible for red wine colour, the yellow to amber colours of white wines are less well understood. phenolics present in the white grapes are evidently involved, and some limited oxidation of these is assumed to play a role in desirable white wine colour development. Brown polymers, resulting from excessive oxidation of white wine catechins, are known to be responsible for the browning of oxidized wines. See ageing and colour.