Wash rhubarb stalks thoroughly and cut into 1/2 inch pieces. Put into a large bowl.
Pour 2 3/4 cups of the sugar on top of the rhubarb and leave in refrigerator overnight. The sugar will draw water from the rhubarb.
Bring the rhubarb and sugar mixture to a boil in a saucepan or in the microwave. Cook for 10 minutes or until tender.
Meanwhile, mix the remaining 1/4 cup of sugar with the package of gelatine. When the rhubarb is cooked, remove from heat and add the gelatine while stirring until the gelatine is dissolved.
Pour into containers and refrigerate.