Wine phenolics derive from the solid parts of the
grapes and are transferred to the wine by maceration of the
pomace during winemaking. The seeds provide mainly procyanidins,
whereas the skins impart wider diversity of phenolics such as
procyanidins, prodelphinidins, anthocyanins, flavonols, benzoic
and cinnamic acids and their derivatives, stilbenes, etc. Between
30% and 40% of these compounds pass into the wine