Any wine with bubbles is a sparkling wine, and they’re made around the globe. Sparkling wines are not carbonated. CO2 is a natural by-product of their fermentation. The bubble-making process begins by adding yeast and sugar to a previously fermented base wine and sealing the tank or bottle in which that second fermentation takes place. Bottle-fermented sparkling wines, such as Champagne, tend to be rich, with significant brioche flavors from yeast.