01 - Submerge jars and lids in boiling water for 10 minutes. Keep jars warm until ready for filling.
02 - Combine diced cantaloupe and fresh lemon juice in a large saucepan and lightly mash with a potato masher.
03 - Bring the cantaloupe mixture to a simmer over medium heat and cook for 5 minutes, stirring occasionally.
04 - Blend the simmered mixture using an immersion blender or regular blender until completely smooth.
05 - Return the puree to the saucepan. Add granulated sugar and stir well to combine.
06 - Bring the mixture to a full rolling boil over high heat, stirring constantly.
07 - Stir in liquid fruit pectin. Return to a rolling boil and boil hard for 1 minute, stirring continuously.
08 - Take the saucepan off the heat and skim off any foam using a spoon.
09 - Carefully ladle hot jelly into prepared jars, allowing 1/4-inch headspace. Wipe rims, position lids, and fasten bands fingertip-tight.
10 - Process filled jars in a boiling water bath for 5 minutes. Remove and cool jars undisturbed for 12-24 hours. Confirm seals before storing.