Red wines are made from black grapes and have a red or blue tint. Most grapes have colorless juice, so to make red wine the grape skins, which contain nearly all of the grapes’ pigmentation, have to remain intact with the juice during all or part of the fermentation process. Tannins are also found in the grape skins, and are transferred into the wine while the skins are in contact with the juice. Besides the difference in color, the primary difference between red and white wines comes are tannins. Found mainly in red wines, they provide a dry, puckery sensation in the mouth and in the back of the throat. They also help preserve wine, allowing most (but not all) red wines to be aged longer than white wines. Popular red wines include Beaujolais, Cabernet Sauvignon, Chianti, Merlot, Pinot Noir and Zinfandel.