From each of the fermented batches of wine a small sample is taken and
tasted by the wine makers. The selected samples are then taken and
combined to give a final master blend, which is called the cuvée.
This can be a very difficult process since it requires the wine makers
to predict the final flavour of the blend after the second fermentation.
The remaining blocks of wine that have not been used in blending are auctioned off to other vineyards.
Bottling, Second Fermentation and Ageing
Sugar and yeast are
added to the final blend to induce a second fermentation. This wine is
then bottled and capped in the bottles that will end up on the shelves
of the wine seller. During the second fermentation the yeast increases
the level of alcohol and adds CO2 which creates the bubbles
in sparkling wine. This process takes about four to six weeks. The yeast
must now remain in the bottle for at least a year to allow the champagne
to age, even though the fermentation process is complete. The bottles rest
horizontally on top of each other where the yeast collects along the bottom
side. Most producers allow the sparkling wine to age for three to seven
years before uncorking and removing the left over yeast. The alcohol
content of the wine is limited because at a certain concentration the yeast
becomes "drunk" and can no longer ferment. This is called lees.