In a small saucepan, heat 1 cup grapefruit juice and sugar over medium heat. Cook, stirring frequently, until sugar is dissolved, about 3 minutes. Stir in Campari and remaining 2¼ cups grapefruit juice. Refrigerate until chilled.
Transfer liquid to an ice cream maker, and freeze according to manufacturer’s instructions until sorbet is a thick, slushy consistency, about 15 minutes. Transfer to an airtight container. Freeze until firm. Garnish with mint, if desired.
Recipe by Southern Lady Magazine at https://southernladymagazine.com/pretty-in-pink-sorbet-recipe/