Yield: about 8 half pints.
8 C. blueberries
4 C. rhubarb, chopped in 1 inch pieces
1 t. lemon rind, grated
2 T. lemon juice
1 C. water
4 C. sugar
In a large heavy saucepan, combine blueberries, rhubarb, lemon rind and juice and water. Bring to a boil, stirring frequently, reduce heat and simmer, very gently, for 10 minutes.
Stir in sugar; increase heat to high and boil vigorously until jam reaches setting point (218 - 220F), 10 to 15 minutes, stirring frequently. Remove from heat, skim off foam and stir for 3 - 5 minutes to suspend fruit evenly throughout jam. Pour into warm sterilized jars and seal.