In biology, autolysis, more commonly known as self-digestion, refers to the destruction of a cell through the action of its own enzymes. It may also refer to the digestion of an enzyme by another molecule of the same enzyme.
In the food industry, autolysis involves killing the yeast and encouraging breakdown of its cells by various enzymes. It is used to give different flavors. For yeast extract, when this process is triggered by the addition of salt, it is known as plasmolysis.
In bread baking, the term (or, more commonly, its French cognate autolyse) is best described as the hydration rest following initial mixing of only flour and water that occurs before kneading has fully developed the gluten; this simplifies the shaping process of the finished dough. The term was coined by French baking professor Raymond Calvel.
In the making of fermented beverages, autolysis can occur when the must or wort is left on the lees for a long time. In beer brewing, autolysis causes undesired off-flavors. Autolysis in winemaking is often undesirable, but in the case of the best Champagnes it is a vital component in creating flavor and mouth feel.