Wine is one of the world's most popular alcoholic beverages. It is most commonly made of fermented grape juice. The chemical balance of grapes is naturally such that grapes can ferment without the addition of sugars, acids, enzymes, etc. Only yeast is used to ferment crushed grapes; the yeast consumes the fructose found in the grapes and converts it into alcohol.

The classification of wine into different varieties can be done according to various methods such as place of origin, vinification methods and style, sweetness and vintage, etc. Historically, wines have been known by names reflecting their origin. Wine varieties such as Bordeaux, Rioja, Mosel and Chianti have names reflecting the traditional wines produced in the named region. Regional wine classification of follows naming conventions or appellations, which are strongest in the European Union. In America, a related system, the American Viticultural Area is used.

Other wine varieties, classified on the basis of vinification methods and style, include red or white wine, sparkling, semi-sparkling or still. Sparkling wines such as champagne contain carbon dioxide which is produced naturally from fermentation or force-injected later. To have this effect, the wine is fermented twice, first in an open container to let the carbon dioxide escape into the air, and a second time in a sealed container where the gas is caught and remains in the wine. Still wines are wines that have not gone through the sparkling wine methods and have no effervescence.

Dessert range from slightly sweet to very sweet while fortified wines are generally sweeter and more alcoholic, with their fermentation process stopped by the addition of a spirit, or with additional spirit added after fermentation. Examples of fortified wines include Port, Madeira, and Banyuls.

Other wine varieties include table wines and cooking wines or cooking sherry which is inexpensive grape wine or rice wine.

Wine varieties also include vintage wine and varietal wine. Vintage wines are those which are made from grapes harvested in a single year and are accordingly dated as such. A varietal wine is made from a dominant grape. In the US, the dominant grape must constitute at least 75% of the wine while in the European Union, the dominant grape must constitute at least 85% of the wine if the name of a single varietal is displayed. If the names of two varietals are displayed, then each must be in such a proportion that the whole adds up to 100%. can be identified by the process of wine tasting. Wine tasting is the sensory examination and evaluation of wine, and fine wines can be identified by their color, smell, taste, and after-taste.