Name a classic cocktail that uses egg whites.

The classic cocktail that uses egg whites is the Whiskey Sour. This drink is traditionally made with whiskey, lemon juice, sugar, and egg white, which is added to create a frothy texture and a silky mouthfeel. The egg white not only enhances the visual appeal of the cocktail with its foam but also balances the acidity of the lemon juice, making for a smoother drinking experience.

Egg whites are common in several cocktails as they contribute a rich texture and improve the overall mouthfeel, which is particularly important in the Whiskey Sour. The shaking of the cocktail with egg whites, known as a dry shake when done without ice, is key to achieving the desired frothy consistency. In contrast, the other options—such as the Martini, Margarita, and Sangria—do not typically include egg whites as part of their ingredients or classic preparation methods.