In the conversion of starch to ethyl alcohol, the following enzymes are used

 $starch\stackrel{\text{ diastase }}{⟶}\text{ Maltose }\stackrel{\text{ maltose }}{⟶}\text{ Glucose }\stackrel{\text{ zymase }}{⟶}\text{ Ethanol }$

Fermentation, for example, is used for preservation in the production of lactic acid, which is found in sour foods such as pickled cucumbers, kombucha, kimchi, and yogurt, as well as for the production of alcoholic beverages such as wine and beer.