Which type of alcohol is primarily used in a cosmopolitan cocktail?

A cosmopolitan cocktail is primarily composed of vodka, which serves as the base spirit. Vodka is selected for its neutral flavor profile, allowing it to blend seamlessly with other ingredients in the cocktail, including cranberry juice, triple sec, and freshly squeezed lime juice. This neutrality not only enhances the overall taste but also allows the fruity and tart notes of the other ingredients to shine through.

In the context of a cosmopolitan, the other types of alcohol listed, such as rum, tequila, and whiskey, have distinct flavors that would significantly alter the character of the drink. Rum tends to be sweet and spicy, tequila carries a distinctive earthy and bold flavor, and whiskey adds richness and complexity. All of these profiles would clash with the intended vibrant and refreshing essence of a cosmopolitan, underscoring why vodka is the ideal choice for this popular cocktail.