Fermented food

Fermented foods are foods produced or preserved by the action of microorganisms. In this context, fermentation typically refers to the fermentation of sugar to alcohol using yeast, but other fermentation processes involve the use of bacteria such as lactobacillus, including the making of foods such as yogurt and sauerkraut. The science of fermentation is known aszymology.

Many pickled or soured foods are fermented as part of the pickling or souring process, but many are simply processed with brine, vinegar, or another acid such as lemon juice.

Fermentation in food processing is the conversion of carbohydrates to alcohols and carbon dioxide or organic acids using yeasts,bacteria, or a combination thereof, under anaerobic conditions. Fermentation usually implies that the action of microorganisms is desirable. The science of fermentation is also known as zymology or zymurgy.

The term "fermentation" is sometimes used to specifically refer to the chemical conversion of sugars into ethanol, a process which is used to produce alcoholic beverages such as wine, beer, and cider. Fermentation is also employed in the leavening of bread (CO₂ produced by yeast activity); in preservation techniques to produce lactic acid in sour foods such as sauerkraut, dry sausages, kimchi, and yogurt; and in pickling of foods with vinegar (acetic acid).