- 1 tablespoon superfine granulated sugar, or to taste
- 1 quart strained fresh pink grapefruit juice (from about 8 large grapefruit), chilled
- 1 cup soju (sometimes called sochu), sake, or vodka, chilled
- Club soda or seltzer, chilled
- Stir 1 tablespoon sugar and 1/8 teaspoon salt into juice until dissolved. Stir in soju and add sugar to taste.
- Pour over ice in tall 8- to 10-ounce glasses (about 1/2 cup grapefruit mixture per glass) and top with a splash of club soda.