- 4 mint sprigs
- 1 tablespoon superfine sugar, or to taste
- 2/3 cup fresh grapefruit juice
- 1 1/2 tablespoons fresh lemon or lime juice, or to taste
- 3 ounces light rum (6 tablespoons), or to taste
- chilled club soda or seltzer water
- Angostura bitters to taste
- Garnish: grapefruit wedges and mint sprigs
- In a cocktail shaker with the back of a spoon crush mint sprigs with sugar and juices until sugar is dissolved. Add rum and about 1 cup ice cubes and shake 30 seconds. Strain mixture into 2 tall glasses filled with ice cubes and top each drink with club soda or seltzer water and a splash of bitters. Stir drinks and garnish with grapefruit and mint.