Make a syrup.
Place the sugar in a pan. Pour in a cup of water. Boil until the sugar dissolves. Cool.
When the syrup has cooled, pour in the coffee. Stir.
Pour the mixture into a container that can go into the freezer. Cover and freeze for an hour.
When the mixture is semi-solid, scrape with a fork. Stir briskly (a wire whisk, if you like a smooth granita; a fork, if you prefer a coarse granita). Do this every 30 to 45 minutes, four to five times.
When you’re happy with the texture of your coffee granita, serve and enjoy.