used for Champagne, all European wines with the designation , , some varieties of and other sparkling wines that have , or fermented in this bottle on the label (note, however, that the unusual ancestral and dioise methods also ferment the wine exclusively in the bottle). Ancestral method The ancestral method () goes under many local names in the various French regions, such as , and . This is by far the oldest method of making sparkling wine and preceded the traditional method by almost 200 years, or possibly even more. The wine that is now called Blanquette de Limoux is considered by wine historians to be the world's first sparkling wine, and was produced in Limoux in 1531 by monks in the monastery of Saint-Hilaire. Wines produced using the ancestral method include among others French wines from Gaillac, Bugey Cerdon and Blanquette de Limoux, German wines from a few vineyards where the method is usually called , and some North American wines. In Italy the name given to a traditional version of the ancestral method is Col Fondo, however producers are increasingly dropping the word from their labels as the name was trademarked in 2002 by two local wineries (as the spelling Colfondo). Although these wineries are not enforcing their trademark rights, they have been unable to come to an agreement with the Consorzio. Under new DOCG law, from 2020 Col Fondo wines will be labelled as Sui Lieviti. Wines made with the ancestral method are sometimes called , popularly abbreviated to pét-nat. Since French wine label regulations ban the word , the appellation from Montlouis-sur-Loire is instead called . There are two general approaches employed by winemakers to produce pét-nat, the choice of which is often determined by location and weather conditions during harvest as well as the scale of production and resources on hand in the winery when it comes to bottling. The first is the "interruption" method, whereby the primary alcoholic fermentation is interrupted by the act of bottling. The wine goes into bottle, sealed under a crown cap, where the still viable yeast, nutrient and sugar allow the primary fermentation to continue and produce the carbon dioxide that forms the bubbles. Malolactic fermentation may also occur in bottle making a small contribution to the carbon dioxide levels. Unlike the traditional method there is no disgorging and dosage, however producers using the interruption method will often