If you don't own an ice cream freezer, transfer mixture to a 13x9x2-inch baking pan. Cover; freeze several hours or until almost firm. Break mixture into small chunks; transfer to a large chilled mixing bowl. Beat with an electric mixer until smooth but not melted. Return to pan. Cover and freeze until firm.
In a saucepan combine 1-1/2 cups sugar and 1 envelope unflavored gelatin. Stir in 1-1/2 cups water. Cook and stir until sugar and gelatin dissolve. Remove from heat. Stir in 1-1/2 cups cold water, 1 cup milk, 1 teaspoon grated lemon peel, 3/4 cup lemon juice, and, if desired, a few drops yellow food coloring. (Mixture may appear curdled.) Continue with step 2, above.Per serving: 109 cal., 0 g total fat (0 g sat. fat), 2 mg chol., 14 mg sodium, 26 g carbo., 0 g fiber, 1 g pro.Daily Values: 1% vit. A, 12% vit. C, 3% calciumExchanges: 3 Other Carbo.