How is wine made?

The main difference between the production of red and white wine is that red wine is made by fermenting the juice in contact with the skins and flesh of the grapes, whereas white wine is made by fermenting just the juice after the skins and flesh have been removed in the press. This is because the colour and tannins which are vital to red wine are found in the skins of black grapes, and these components are best extracted during (and sometimes after) alcoholic fermentation.