The evolution of amino acids in champagne has been studied over a period of several years from the start of the bottle fermentation to aging for 4 to 5 years in contact with the yeast. After the excretion of amino acids by yeasts at the end of the bottle fermentation the concentration of amino acids remains stable for several months. Then it begins to rise again slowly but continuously. This second phase of enrichment with amino acids corresponds to the autolysis of the yeast cells. This phenomenon has also been studied with active dry yeasts after rehydration. It depends on some parameters such as the pH, the ethanol concentration, and the temperature. For champagne the age of the yeast sediment also plays a role.
Autolysis proceeds only if the wine is aged for several months in contact with the yeast. Indeed, the yeasts are the seat of intracellular proteolytic activity which causes the degradation of cytoplasmic constituents and the enrichment of the wine in amino acids. Autolysis has truly a great influence on the organoleptic properties of champagne, particularly on its aromatic properties. Investigations are now underway for the production of yeast autolysates in fermenters for the purpose of addition to the wine at the time of the bottle fermentation in order to accelerate the aging process.
- Copyright 1982 by the American Society for Enology and Viticulture