Bordeaux has made bottle-fermented sparkling wine since the late nineteenth century, when négociants applied the méthode traditionnelle to the region's whites; the appellation Crémant de Bordeaux formalised the practice in 1990. Sémillon leads the blend, its roundness playing against Sauvignon's citrus snap, with the Cabernets pressed white — or left briefly on skins for a rare rosé.
It remains the region's quietest appellation, a few million bottles from vines mostly in the Entre-deux-Mers hills — but as a window on what Bordeaux's white grapes do with bubbles, and at its price, it is one of the Gironde's better-kept secrets.