Wash the pears to remove any dust, dirt or pesticide residue. Slice the pears from the core. Place the sliced pears in a saucepan with a quarter cup of water. Heat over medium heat until the pears are soft. Mash with a potato masher if desired to realize as much juice from the pears as possible.

Strain the mashed pears through a jelly bag into a large bowl. If a jelly bag is not available, use a colander lined with cheesecloth over a large bowl.

Pour the juice back into the saucepan. Add the contents of one box of pectin slowly, making sure to dissolve all of the powder into the juice.

Bring the mixture to a boil and add the lemon juice. Add in the sugar one cup at a time until dissolved. Return to a boil for one minute or until the juice thickens.

Ladle the contents into clean jelly jars. Place a lid on each jar and seal with a jar ring.

Process the jelly for 10 minutes in a boiling water bath. Remove from the canner and let sit on a wire or wooden rack until cool. Check each lid for proper sealing. Refrigerate any jars that did not seal properly.