In a large pot, combine pears, sugar, water, and lemon juice. Bring to a boil.
Cook, uncovered, for 1 1/2 to 2 hours or until mixture thickens. It should reach a spreadable consistency.
Remove from heat. Ladle into seven hot half-pint jars. Be sure to leave 1/4" headspace.
Wipe rims. Place lids on the jars. Screw on lids until fingertip tight.
Place jars in canner or large pot. The jars must be completely covered with water. Bring to a boil. Let boil, or process, for 10 minutes.
Remove jars and cool. After 24 hours, the jars that haven't sealed should be placed in the refrigerator.