Combine all of the ingredients in a cocktail shaker with 3-4 ice cubes.
Shake!
Pour over ice in a highball glass.
Enjoy!
Notes
Culinarian Tips, Tricks, and Suggestions:Freshly squeezed grapefruit juice brings a crisp, bright flavor burst to this cocktail. We have found that while this cocktail can be made with bottled grapefruit juice, it is essential to make sure that you use unsweetened 100% grapefruit juice versus sweetened juice or cocktail mix.