The chemical equation for wine fermentation when starting from glucose is C6H12O6 = 2CO2 + 2CH3CH2OH, and when starting from maltose or sucrose, it is C12H22O11 = 4CO2 + 4CH3CH2OH. In both processes, the products are carbon dioxide and ethyl alcohol. Yeast cells are used in the fermentation process to extract energy from the sugar.
Winemakers use the natural yeasts found on grape skins to produce wine. The grapes are crushed and then soaked and heated to allow the yeast to convert sugar into ethyl alcohol. Wine and other alcoholic beverages are preserved due to the toxic properties of ethyl alcohol. It is these properties that causes a person to become intoxicated when drinking alcohol.