Prepare the Ingredients: Juice a fresh grapefruit to get about 2 oz of fresh grapefruit juice. Prepare the simple syrup if you don’t have any on hand (mix equal parts sugar and water, heat until sugar dissolves, then cool).

Mix the Cocktail: In a cocktail shaker, add the fresh grapefruit juice, vodka, triple sec, and simple syrup.

Shake Well: Fill the shaker with ice and shake well for about 15 seconds until the mixture is well chilled.

Strain into Glass: Fill a highball glass with ice and strain the mixture from the shaker into the glass.

Top with Soda Water: Top off the drink with soda water to give it a fizzy finish.

Garnish: Garnish with a slice or wedge of grapefruit on the rim of the glass.

Serve and Enjoy: Serve immediately and enjoy your refreshing Grapefruit Crush.