Step 1

In a saucepan, simmer the sugar and water to dissolve the sugar. Let cool.

Step 2

In a 9-inch square, glass baking dish, combine the sugar syrup and grape juice. Freeze for 30 minutes. Using 2 forks, scrape any frozen crystals into the center of the dish. Continue to freeze, scraping every 30 minutes, until the mixture is totally frozen and granular, about 4 hours total. Scrape the granita into chilled bowls and serve.