Autolysis
The breakdown of dead yeast cells during extended lees contact, which releases flavour-active compounds into the wine — primarily producing brioche, toast, biscuit, and creamy aromas.
In depth
Autolysis literally means "self-digestion." After fermentation, dead yeast cells contain enzymes that, when the cell walls break down, release their contents into the surrounding wine. These contents include mannoproteins, peptides, fatty acids, and nucleotides that contribute to the wine's texture, aroma, and structure.
The rate and extent of autolysis depends on: temperature (warmer = faster breakdown), time on lees, and whether the lees are stirred (batonnage accelerates contact). Significant autolysis takes months to years.
In Champagne production, the legal minimum lees contact is 15 months for non-vintage and 36 months for vintage Champagne. Prestige cuvées (like Dom Pérignon and Krug) may spend 6–10 years on the lees, developing extraordinary toasty, complex autolytic characters.
The characteristic autolytic descriptor in traditional method sparkling wine is "yeasty" or "bready" — often described as fresh brioche, toast, or biscuit. These are secondary aromas resulting from winemaking, not primary aromas from the grape.
Related exam topics
Frequently asked questions
- What is the difference between autolysis in Champagne and lees ageing in Burgundy?
- Both involve contact with dead yeast cells, but the context differs. In Champagne, autolysis occurs inside sealed bottles during the long ageing period — the yeast sediment cannot be removed until disgorgement. The confined environment and extended time produce strong autolytic characters. In Burgundy, lees ageing happens in open barrels, often with batonnage to keep lees in suspension. The autolysis is gentler and shorter, adding texture and subtle complexity rather than dominant yeasty notes.
Practise questions on this topic
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