"Jams, jellies, preserves, conserves, marmalades, and butters are all gelled or thickened fruit products. Most are cooked and preserved with sugar. Their individual characteristics depend on the kind of fruit used and the way it is prepared, the ingredients and their proportions in the mixture, and the method of preparation."
I learn this from an old farm lady, grated your Paraffin and put approximately 3 tbsp. in the bottom of your jar then add your hot jelly, Paraffin will melt and float to the top ceiling the jar.