Yeast is a crucial ingredient in the production of alcoholic beverages, responsible for fermenting sugars into alcohol and carbon dioxide. In cocktails and alcohol production, its primary role is behind the scenes during the brewing and distilling processes.

In cocktail preparation, yeast influences the character and flavor of the base spirits used. For example, different strains of yeast contribute varying flavor profiles to beers and spirits. While not directly added to cocktails, the flavor nuances created by yeast fermentation in spirits like whiskey, rum, or beer can greatly affect the overall taste and quality of the finished drink.