- Whisk together all ingredients in large bowl until sugar is dissolved. Pour mixture into 9 x 13-inch baking pan. Cover and freeze until partially frozen, about 2 hours. Remove from freezer and stir with fork, breaking up ice crystals. Cover pan and return to freezer, stirring mixture every 30 minutes, until completely icy, about 3 hours longer.
- Scoop granita loosely into airtight container and freeze up to 2 weeks. To serve, scoop into glasses or, using a fork, scrape along granita transferring ice shards to glasses.
- Per serving: about 2/3 cup
For the best results, use freshly squeezed grapefruit juice in this recipe. The flavor will be far superior without the harsh bitterness that store-bought juice sometimes has. One large grapefruit yields about 1 cup of juice.