Prickly Pear Cactus & Cranberry Jelly

Singe cactus fruit to remove the spines from the fruit. Cut fruit up and just barely cover with water. Bring to boil and simmer for 10 minutes. Run the juice through some cheesecloth and save the juice. Measure prepared juice and lemon juice into a 6 or 8 quart saucepan. Measure sugar into separate bowl, and set aside. Add 1 package of pectin to fruit juice and mix thoroughly. Bring to a rapid boil over high heat. Constantly stirring to prevent scorching. When full rolling boil, add sugar and mix well. Bring to full rolling boil and continue to boil for 2 minutes. Remove from heat. Skim off any foam. Fill hot jars and quickly cover with lids and screw bands tightly. Process the filled jars in boiling water for 15 minutes. Turn jars on lids (upside down) for 5 minutes and then turn upright. After 1 hour check to see that all have sealed.