In a Madras cocktail, which juice is mixed with the vodka?

In a Madras cocktail, cranberry juice is the key component mixed with vodka. This cocktail is traditionally made with vodka, cranberry juice, and orange juice, which gives it a vibrant color and a sweet, tangy flavor profile. The use of cranberry juice is essential as it not only contributes a significant part of the overall taste but also enhances the drink's refreshing quality. The fruitiness of cranberry juice pairs well with vodka, creating a balanced and enjoyable drink.

While pineapple, grapefruit, and orange juices are delicious in their own right, they are not part of the classic Madras recipe. Pineapple juice tends to add a tropical sweetness that is suitable for tiki drinks, grapefruit juice has a more bitter profile, and while orange juice is commonly used, it is not the primary juice that defines a Madras cocktail. Therefore, cranberry juice is the correct answer as it is fundamental to crafting this specific cocktail.