The jam will keep for thirty days in the refrigerator, but if you want to keep it longer you can store in it plastic containers in the freezer.
- Toss together the sugar and the rhubarb, and let the mixture sit for about ten minutes.
- This will draw the juice out of the fruit.
- Once the sugar is dissolved, put the mixture in a pan and bring it to a boil.
- When the rhubarb has softened, add the gelatin and stir until it's completely dissolved.
- Allow the jam to cool completely, then transfer it into mason jars.