Méthode Ancestrale is, perhaps, the oldest method of making sparkling wine. It goes by many names, but the most common in Australia is pétillant naturel (petnat). As with all sparkling wine production, the bubbles come from carbon dioxide trapped in the wine. However, a key difference in méthode ancestrale is that the wine is bottled part-way through its first (and only) fermentation. The wine finishes fermenting in the bottle, releasing carbon dioxide that is trapped and thus, creating bubbles.
The wines are often left unfiltered, so they can be hazy. The carbonation tends to be more gentle than in a wine made by the traditional method, and there can be some residual sweetness.
