Production
The natural chemical balance of grapes lets them ferment without the addition of sugars, acids, enzymes, water, or other nutrients. Yeast consumes the sugars in the grapes and converts them into alcohol and carbon dioxide. Different varieties of grapes and strains of yeasts produce different styles of wine. The well-known variations result from the very complex interactions between the biochemical development of the fruit, reactions involved in fermentation, terroir and subsequent appellation, along with human intervention in the overall process. The final product may contain tens of thousands of chemical compounds in amounts varying from a few percent to a few parts per billion.
Wines made from produce besides grapes are usually named after the product from which they are produced (for example, rice wine, pomegranate wine, apple wine and elderberry wine) and are generically called fruit wine. The term "wine" can also refer to starch-fermented or fortified beverages having higher alcohol content, such as barley wine, huangjiu, or sake.