Shake the first 3 ingredients with ice, then strain into an ice-filled glass. Top with chilled soda water, and garnish.
Grapefruit-Cinnamon CordialIn a saucepan over medium heat, combine 1 quart of grapefruit juice with 2 cups of simple syrup (1:1). Add the zest from 2 grapefruits and 3 cinnamon sticks, and simmer for 20 minutes. Let the mixture cool, then refrigerate in a sealed container for 1-2 days. Strain the mixture and bottle for use; keeps refrigerated for up to 2 months.
