The finest sparkling wines and sparkling ciders use the Traditional Method also known as the Méthode Traditionelle. A base wine or cider is made from primary fermentation using wild or cultured wine yeast to convert the grape sugars, or in the case of cider, apple fructose into alcohol. These base wines or ciders are blended together before being bottled with the addition of liqueur de tirage a mixture of Champagne yeast and sugar which triggers a secondary fermentation in the bottle. Bubbles are born and dissolve into the wine or cider making it sparkle. The wine or cider then ages on the dead yeast called lees which self-destruct through a process called yeast autolysis giving complex bready, brioche and nutty flavours. Lees are removed by riddling the bottles by hand or in gyropalettes before being disgorged and topped up with a dosage of reserve wine or cider.