A biological process in which yeast converts simple sugars into ethanol, carbon dioxide and a number of other by-products. This process is used in a variety of industries, including the production of alcoholic beverages and yeast pastries. The energy sector uses alcoholic fermentation to produce bioethanol from plants grown specifically for this purpose. These are primarily maize, sugar beet, sugarcane, potatoes or grain. Bioethanol is then used as a substitute or additive for car fuels.