Wine is an alcoholic drink, usually made of fermented grape juice. The natural chemical balance of grapes is such that they can ferment without the addition of sugars, acids, enzymes or other nutrients. Wine is produced by fermenting crushed grapes using various types of yeast. Yeast consumes the sugars found in the grapes and converts them into alcohol. Different varieties of grapes and strains of yeasts are used depending on the type of wine being produced.