- 3 ounces fresh pink grapefruit juice
- 1 1/2 ounces London dry gin
- 1/4 ounce St-Germain (elderflower liqueur)
- India Pale Ale (for serving)
- Grapefruit twist (for serving)
- Combine grapefruit juice, gin, and liqueur in a cocktail shaker. Fill shaker with ice and shake until outside of shaker is frosty, about 30 seconds. Strain into a rocks glass filled with ice and top off with ale. Garnish with grapefruit twist.