Méthode Ancestrale is a production method of sparkling wine in which the alcoholic fermentation is stopped, and is continued in the bottle. In contrast to the Méthode traditionnelle there is no addition of sugar, and the wine is not disgorged. The fermentation in the bottle will stop when the sugar is depleted, and the lees will remain in the bottle. The Méthode Ancestrale is the oldest form of sparkling wine production.
Sometimes still wines with residual sugar undergo an unintended second fermentation in the bottle, resulting in a (light) sparkling wine. This is considered a wine fault caused by insufficient removal of yeasts and/or protection of the wine with sulfite.