Col Fondo: Sparkling wine production method for traditional Prosecco, in which the spent yeast cells, or lees, left over from the secondary fermentation are not disgorged.
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.
Secondary Fermentation: The process that creates the bubbles in sparkling wine. As the wine is bottled, a small amount of yeast and sugar is added before the bottle is sealed with a sturdy crown cap. The yeasts quickly start fermenting the sugars, producing alcohol and carbon dioxide. Since the gas cannot escape, it dissolves into the wine.
Disgorgement: When making sparkling wine, this technique is used to remove frozen sediment remaining in the bottle after the second fermentation. Through the riddling process, the sediment settles in the bottle neck and the neck is then dipped into a brine solution and frozen. Working quickly, the bottle is turned upright and the crown cap removed. The plug of frozen sediment is ejected by the pressure of the carbon dioxide. Also known as Dégorgement.
Lees: Sediment—dead yeast cells, grapeseeds, stems, pulp and tartrates (harmless tartaric acid crystals)—remaining in a barrel or tank during and after fermentation. Immediately following fermentation, wine should be racked off of the gross lees, the large particulate matter such as seeds, skins and stems, which are rich in spoilage organisms. The wine may be aged for an extended period on the fine lees, however, in what's called "sur lie" aging. Fine lees, the dead yeast cells leftover from fermentation, can enhance an aging wine with added richness, flavor and aroma complexity, and can also bind with excess tannins.