In order for the juice to become Champagne, a number of fermentation processes take place.
After clarification, the grape musts may also be chaptalised to produce a wine with a maximum alcohol level of 11 % by the end of fermentation.
Yeasts are added to convert the sugar contained in the juice into alcohol, carbon dioxide, superior alcohols and esters.
Following the alcoholic fermentation, the wines are clarified again. These still clear wines (“vins clairs”) can be used for the next stages of winemaking or set aside to be used in future blends.
Malolactic fermentation (optional)
After the alcoholic fermentation, the winemaker may decide to allow malolactic fermentation, which is done using bacteria belonging to the speciesOenococcus.
This reduces and softens the wine’s acidity and alters its sensory profile, introducing milky and brioche notes.
Bottle fermentation (prise de mousse- capturing the sparkle)
In order to kick start this fermentation, the winemaker adds to the wine a bottling liqueur (“liqueur de tirage”), composed of yeasts and 20-24 grams per litre of sugar, in order to produce a pressure by the end of fermentation of up to 5-6 atm.
During this fermentation process, the yeasts consume the sugar, transforming it to alcohol and carbon dioxide and releasing esters and other superior alcohols that contribute to the wine’s sensory profile.