There are between 5,000 and 10,000 wine grape varieties in the world. Only several hundred are actually used to make most wines, however, and the average person is familiar with only a fraction of those. Wine grape varieties can be divided into several different categories, including green grapes, purple or black grapes, and hybrids, which are cross-species grapes. There are relatively few hybrids compared to green or black types of grapes. Wine grape varieties generally have the same names as the wines in which they are used.
Though factors such as the location of the vineyard and the skill and techniques of the wine makers affect the flavor of wines, the primary determinant of taste is the type of grape itself. The specific grapes' tastes will still vary somewhat, but the general taste of a specific type of grape is relatively consistent. For example, two types of green grapes used to make white wine are Chardonnay and Pinot Blanc. Chardonnay is a popular, easy-to-grow grape and buds early, whereas Pinot Blanc is often used in California sparkling wines, but is also grown in Italy and Austria. When made into wines, both usually taste fruity, similar to peaches or melons.
Cabernet Sauvignon is a grape used for red wines. This grape is often grown in California and Australia, and is famous in Bordeaux. It is said to have a cedar or blackberry flavor. The Cabernet Sauvignon grape also has a high amount of a substance called tannin.
Tannin allows wines to age well. This means the higher the tannin content, the longer the wine may age to increase its flavor. Tannin is more important to red wine grape varieties because it is found in the skins and stems which, although often removed in white wine production, are generally not removed in red wine production.
Another red wine grape is Merlot. Merlot has less tannin than many other red wines and is often blended with other wines, particularly Cabernet Sauvignon in Bordeaux. It is grown in California and New York in the United States, and France, Italy, and Australia worldwide. Merlot generally tastes honeyed, slightly minty, or of cherries.
Still other wine grapes can be made into either red or white wines. Pinot Noir and Zinfandel are both red grapes and, when whole, are used in red wines. When the skins are removed, however, Pinot Noir can be used in Champagnes and Zinfandel is used to make white Zinfandel wine.
Vidal Blanc is an example of a hybrid wine grape. It is created by crossing the Ugni Blanc and Seibel parent grapes. Vidal Blanc is a late-harvest grape and is used in both sweet wines and ice wine. It is generally grown in the northeastern United States.