Which ingredient is used in both Sex on the Beach and Rum Runner cocktails?

Cranberry juice is a key ingredient in both Sex on the Beach and Rum Runner cocktails. In Sex on the Beach, cranberry juice is combined with vodka, peach schnapps, and orange juice, contributing to the cocktail's sweet and fruity flavor profile. In Rum Runner, cranberry juice is utilized alongside rum, banana liqueur, and other fruit juices, providing a refreshing and tangy balance to the drink.

The usage of cranberry juice in both cocktails showcases its versatility as a mixer, allowing for vibrant flavors while still complementing the other ingredients involved. This commonality highlights the ingredient's popularity in various cocktail recipes, making it a staple in many bartending settings.