In large stainless steel or enamel pot, crush 3 cups blueberries with a potato masher.
Add remaining berries, sugar, lemon juice and lemon rind.
Bring to a boil over medium-high heat and boil for 15 to 20 minutes or until thick, stirring often.
Skim off any foam.
Ladle jam into hot jars to within ¼" of top rim.
Can jam using preferred Safe Canning method.
