Autolysis

What it is

Autolysis is the gradual breakdown of dead yeast cells that sit at the bottom of a Champagne bottle during ageing on the lees (sur lattes). Not the second fermentation itself but what happens afterwards. It’s autolysis, not the bubbling, that gives Champagne its complexity and recognisable character.

How it works

During the second fermentation (six to eight weeks after tirage) the yeasts convert sugar into alcohol and CO₂. After that the yeasts die; they’re out of food. The dead cells settle on the bottom of the horizontally lying bottle. Over the months and years that follow, their cell walls break open and internal compounds are released into the wine:

• Amino acids and peptides (brioche, hazelnut, yeasty notes)
• Polysaccharides (creamy texture, fine mousse)
• Fatty acids and esters (subtle aromatic layers)
• Mannoproteins (reduce the perception of acidity)

A slow biochemical process that can continue for decades.

How long

The Comité Champagne sets the minimums:

• Non-vintage: minimum 12 months on the lees (total cellar ageing minimum 15 months)
• Vintage (millésime): minimum 36 months on the lees

In practice top producers go substantially longer. Krug Grande Cuvée averages seven years, Dom Pérignon eight to ten, Bollinger R.D. ten to fifteen.

In the glass

The longer the autolysis:

• The mousse becomes finer and creamier
• The aromatic profile shifts from fresh fruit (citrus, apple) to pastry (brioche, croissant, hazelnut, toasted bread)
• The texture becomes fuller and softer
• The acidity feels rounded, not sharp

Not only Champagne

Every sparkling wine made by bottle fermentation (méthode traditionnelle, Cava, Franciacorta, Crémant, English sparkling) undergoes autolysis. The difference lies in how long and in the base wine quality. With Prosecco (tank method) autolysis is virtually absent: hence the more fruit-driven, simpler taste.