Autolysis: cell breakdown, not fermentation
The standard
As an enzymatic cell breakdown, autolysis is the biochemical process that gives lees ageing its effect on texture: not the contact with the yeast, but the breakdown of its cells.
Criteria
- The process requires the death of the yeast cells, not merely their contact
- It releases cell components into the wine that raise texture and fullness
- Its effect grows with the time the wine rests on the lees
Distinction
Autolysis ≠ lees ageing: lees ageing is the condition, the enzymatic cell breakdown the process that runs within it. Autolysis ≠ alcoholic fermentation: fermentation turns sugar into alcohol, autolysis takes apart the yeast cells after its end.