1

Bring sugar and water to a boil over medium-high heat, stirring occasionally until sugar dissolves. Reduce heat, and simmer 5 minutes. Remove from heat, and cool.

2

Process watermelon in food processor until smooth. Pour watermelon puree through a fine wire-mesh strainer into a bowl, discarding pulp.

3

Combine sugar syrup, watermelon juice, wine or grape juice, and lemon juice in covered container. Let chill overnight. Pour into container of 1 gallon electric freezer; freeze according to manufacturer's instructions. Serve immediately, or place into airtight container and put in freezer.