Guniness Stout Ice Cream

1 cup water

2 tablespoons cornstarch

1/2 cup sweetened condensed milk

1 1/2 cups evaporated milk

1/4 teaspoon salt

1/2 cup sugar

1/2 cup Guinness stout

In a heavy saucepan whisk together the water and the cornstarch and simmer the mixture over moderate heat, whisking, for 2 minutes. Add the milks, the salt, and the sugar, heat the mixture over moderately low heat, whisking, for 1 to 2 minutes, or until the sugar is dissolved, and remove the pan from the heat. Let the mixture cool completely, stir in the Guinness, and freeze the mixture in an ice-cream freezer according to the manufacturer's instructions.

Makes about 1 quart