|Sugar||2 Cup (32 tbs)|
|Grapefruit rind||1 Tablespoon, grated|
|Water||3 Cup (48 tbs)|
|Grapefruit juice||3 Cup (48 tbs)|
|Lemon rind||1 Teaspoon, grated|
|Lemon juice||1⁄2 Cup (8 tbs)|
Combine the sugar and water in a saucepan.
Bring to a boil, reduce the heat, and simmer, uncovered, for 5 minutes.
Cool to lukewarm.
Add the grapefruit juice, grapefruit rind, lemon rind, and lemon juice.
Strain the mixture into the freezer container of an electric ice cream maker.
Follow the manufacturer's directions for freezing.