White wine is a wine that is fermented without skin contact. The colour can be straw-yellow, yellow-green, or yellow-gold.It is produced by the alcoholic fermentation of the non-coloured pulp of grapes, which may have a skin of any colour. The wide variety of white wines comes from the large number of varieties, methods of winemaking, and ratios of residual sugar. White wine is mainly from "white" grapes, which are green or yellow in colour, such as the Chardonnay, Sauvignon blanc, and Riesling. Some white wine is also made from grapes with coloured skin, provided that the obtained wort is not stained.