Score grapefruit peels in quarters. Remove peel, including as much of the white pith as possible. Cut into 1/4-inch strips. Pour 8 cups water in 5 or 6-quart Dutch oven. Add peel. Bring to a boil. Reduce heat; simmer 10 minutes. Drain peel. Repeat process, using fresh water. In same Dutch oven, mix 1 1/2 cups of the sugar, the juice and corn syrup. Bring to a boil, stirring occasionally. Stir in peel. Reduce heat until mixture is a slow rolling boil. Cook 30 minutes or until most of the syrup is absorbed, gently stirring occasionally. Remove from heat. Gently stir in gelatin. Let cool 10 minutes. Remove peel from syrup to a large cooling rack to drain any excess syrup. Spread remaining 1 cup sugar on a large piece of waxed paper. Roll a few pieces of peel at a time in the sugar to coat well. Cool in single layer on another large cooling rack. Let dry for 12 hours. Store loosely covered in layers separated by sheets of waxed paper. Tip: Use the peeled grapefruits in a salad or just for fresh fruit. Tip: Put grapefruit peels in mason jars or other decorative storage containers and give away as gifts!