Autolysis
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. The term derives from the Greek words αὐτο- ("self") and λύσις ("splitting").
Autolyised yeast can be used at a nutrient for yeast in subsequent fermentations.
The decomposition of dead yeast cells that can be favorable or unfavorable, depending on the wine, the yeast, and the process involved. The favorable process can occur in wines that are aged sur lie ("on the lees"). Certain wines such as Chardonnay or sauvignon blanc benefit from autolysis because they gain complexity during the process that enhances their structure and mouthfeel, give them extra body, and increase their aromatic complexity. Aging sur lie is usually done with an accompanying regime of periodic lees stirring that can result in a creamy, viscous mouthfeel. See Lees and Sur Lie aging.