Alcoholic beverages are defined as beverages that contain ethanol $\left( C _{2} H _{5} OH \right)$. This ethanol is almost always produced by fermentation, the metabolism of carbohydrates by certain species of yeast under anaerobic or law-oxygen conditions. Beverages such as, wine, beer, or distilled spirits all use yeast at some stage of their production.

Yeast the most common one being Sacharomyces cerevisiae, is used in baking as leavening agent, where it converts the food/fermentable sugars present in dough into the gas carbon dioxide. This causes the dough to expand or rise as gas forming pockets or bubbles. When the dough is baked, the yeast dies and the air pockets 'set', giving the baked product a soft and spongy textures.

Cheese is formed by partial degradation of milk by different other microorganisms