A decomposition of dead yeast cells that occurs in wines that are aged SUR LIE (“on the LEES”). Winemakers believe that certain wines—like those made with CHARDONNAY or SAUVIGNON BLANC grapes—benefit from autolysis because they gain complexity during the process. Autolysis affects SPARKLING WINES made via MÉTHODE CHAMPENOISE because yeast cells and a mixture of sugar and wine (DOSAGE) are added to create a second fermentation in the bottle. The sparkling wine is then aged with the yeast cells in the bottle (sometimes for up to 10 years), which adds complexity to both BOUQUET and flavor.