In red wine production, the crushed grapes are usually placed in a tank without drainage and left there during the alcoholic fermentation in order to extract tannins, colour and flavour from the skins and seeds.
Skin contact stage can also be practiced on whites in order to make them more full-bodied and aromatic. It should only be performed on ripe healthy grapes, is best carried out at low temperatures (5 - 10ºC), and pectolytic enzymes may be used.

Skin contact is carried out to help achieve only certain wine styles, and the results will vary enormously according to the variety used and grape maturity.