In a large bowl, crush berries using a potato masher. Measure 1 1/2 cups crushed berries. Stir rhubarb into the 1 1/2 cups crushed berries. Add sugar and lemon peel; stir to combine. Allow to stand at room temperature for 10 minutes, stirring occasionally.

In a small saucepan, combine the water and pectin. Bring to boiling, stirring constantly. Boil hard for 1 minute, stirring constantly. Remove from heat. Add pectin mixture to fruit mixture, stirring for about 3 minutes or until sugar dissolves and mixture is no longer grainy.

Ladle hot jam into half-pint freezer containers, leaving a 1/2-inch headspace. Seal and label. Let stand at room temperature for about 24 hours or until set. Store for up to 3 weeks in the refrigerator or for up to 1 year in the freezer.