4 1/2 cups blueberries -- fresh or frozen
7 cups sugar
2 tablespoons lemon juice
Zest of 2 lemons
9 ounces liquid pectin

Pick over the fresh blueberries to remove any stalks and rinse under cold water. Drain well and place in a large heavy-bottomed saucepan. (Do not rinse or thaw frozen berries.)

Crush the berries slightly with a potato masher or pestle. Stir in the sugar, lemon juice, and zest. Bring to a boil over medium-high heat, stirring often. When the mixture reaches a full boil, cook for 1 minute. Stir in the pectin. Return to a full boil, then cook for another minute.

Ladle into hot, sterilized jars leaving 1/4-inch of headroom. Wipe the rims clear and put the lids on top of the jars. Process in a boiling water bath for about 5 minutes. Remove from the water and cool completely at room temperature.

This recipe yields about 6 half-pints.