Technique
Tirage
Bottling of the base wine with liqueur de tirage (sugar + yeast) to start the second fermentation in the bottle. The opening of the méthode champenoise.
What it is
Tirage is the stage in which the still base wine goes into the bottle together with a liqueur de tirage, the mix that triggers the second fermentation inside the bottle. It is the first essential step of the méthode champenoise after the assemblage of the base wine is complete.
What happens
In a Champagne house’s tirage hall, three components come together in every bottle:
- Base wine (vin clair), the assembled still wine at around 10.5 percent alcohol
- Liqueur de tirage, a mix of wine, sugar (~24 g/l) and yeast cultures plus a clarifying agent (bentonite)
- Crown cap, the temporary seal for the years of ageing to follow
The yeast starts converting sugar into alcohol and CO₂. Because the bottle is sealed and the CO₂ can’t escape, pressure builds to about six bars, comparable to a double-decker bus tyre.
When
Classically in the spring after the harvest. The base wine has been through winter, settled and stabilised. For vintage Champagne: the spring after harvest. For non-vintage: the same, but with assemblage using reserve wines.
Legally
The Comité Champagne mandates tirage in glass. Other sparkling wines can do tirage in tank (Charmat method for Prosecco) but that style isn’t called méthode champenoise.
What follows
After tirage the bottle goes horizontal in the cellar for the second fermentation (~four to eight weeks) followed by the autolysis phase. The law sets a minimum of twelve months on the lees for non-vintage, three years for vintage. In practice top producers go substantially longer.