Definition: Bottle fermentation

A specific stage in the winemaking process that produces sparkling wines. Once the still wine cuvée has been made, yeast and a small amount of cane sugar (liqueur de tirage) are added to facilitate the second fermentation. The wine is then bottled, corked and laid down on racks in deep, cool (around 12°C) and humid cellars. This second fermentation takes place very slowly, away from light, in order to obtain a fine, light and persistent mousse. After the mousse has formed, the wine needs to mature for an average of three years to reach its full potential. Next comes riddling, disgorging and, once the void has been filled with a mixture of wine and dosage liqueur, the bottle is finally corked, muzzled and dressed. This is a description of the (classic) Champagne method. In other sparkling wine-producing regions, the process is often simplified. See champagnisation.