MATURATION ON LEES

Deep inside the cellar, protected from the light and kept at a constant temperature of around 12°C, the bottles embark on a long period of maturation – an all-important process of aging that is a major feature of Champagne winemaking.

According to the rules of the Champagne appellation, wines may not be bottled until the 1st of January following the harvest. They must then spend a minimum of 15 months maturing in the producer’s cellars, of which 12 months is maturation on lees. Vintage cuvées are matured for at least three years. In practice, most Champagne wines are cellared for considerably longer than this.

The lees mainly consist of yeasts that have multiplied in the bottle and formed a deposit. By the end of second fermentation, all the sugars have been consumed and the yeasts gradually die and decompose. The process is known as autolysis, releasing molecules that are slowly transformed as they interact with those in the wine.

The special tirage stopper meanwhile allows minute quantities of oxygen to enter the bottle and small amounts of carbon dioxide to escape - in other words, the seal is not perfectly airtight. The choice of stopper is critical in determining the speed of the Champagne’s development.

These two processes – autolysis and slow oxidation through the stopper – occur simultaneously in the course of maturation on lees. Together they encourage the development of tertiary aromas, slowly transforming the floral, fruity notes of young Champagne wines into the riper, jammier, nuttier aromas that are typical of more mature wines. Very old wines have a distinctively toasty bouquet, with a characteristic whiff of damp forest floor.