Ancestral Method: An inexpensive but risky and difficult-to-control method of producing sparkling wine, and almost certainly the oldest, in which the primary fermentation is stopped before completing, and a secondary fermentation occurs in the bottle, ending when the yeast cells deplete the supply of residual sugar. There is no dosage, or sugar addition, to kick-start the secondary fermentation, and the wine is not disgorged to remove any sediment or lees remaining afterward.
Charmat: A less expensive, mass-production method for producing bulk quantities of sparkling wine. The second fermentation takes place in a pressurized tank, rather than in a bottle, decreasing lees contact and producing larger, coarser bubbles. The wine is filtered under pressure and bottled. Also known as the bulk process or tank method. Wines made this way cannot be labeled méthode Champenoise.
Méthode Traditionnelle: The labor-intensive process whereby wine undergoes a secondary fermentation inside the bottle, creating bubbles. The process begins with the addition of a liqueur de tirage (a wine solution of sugar and yeast) to a bottle of still base wine, triggering a secondary fermentation inside the bottle which produces both carbon dioxide and spent yeast cells, or lees, which are collected in the neck of the bottle during the riddling process. The lees are then disgorged from the bottle, and replaced with a solution of wine and sugar, giving the sparkling wine its sweetness. All Champagne and most high-quality sparkling wine is made by this process. Also known as méthode Champenoise, méthode classique and metodo classico.
Tank Method: Also known as charmat, a less expensive method for making sparkling wine. The tank method is used to produce bulk quantities of inexpensive sparkling wines. The second fermentation takes place in a pressurized tank, rather than in a bottle, decreasing lees contact and producing larger, coarser bubbles. The wine is filtered under pressure and bottled. Wines made this way cannot be labeled méthode Champenoise.