Prise de mousse

What happens in the bottle

After tirage the bottles lie in the cellar. The yeast ferments the added sugar into alcohol and carbon dioxide. The bottle is sealed, so the gas cannot escape and dissolves in the wine.³ The Union des Maisons de Champagne gives these figures:²

• cellars are kept at 9-12 °C;
• the alcohol rises by roughly 1.2-1.3 degrees;
• the build-up of pressure tails off within two months;
• bottles are designed to withstand 12 atmospheres.

The final pressure is about 6 bar at 20 °C.^1,2 Why pressure depends on temperature is explained on CO2 and pressure in the bottle.

Where the step is used

In the traditional method the wine stays in this bottle until sale, and Champagne must be sold in the bottle in which the prise de mousse took place, with exceptions for bottles under 37.5 cl or over 150 cl.^4,5 In the transfer method the same fermentation happens in a bottle, but the wine is later emptied and filtered.³ In the tank method the equivalent fermentation takes place in a closed tank instead.⁶

Next

When fermentation ends, the dead yeast stays in the bottle: this is the start of ageing on lees.