Raspberry Plum Jam

4-1/2 cups chopped or coarsely ground peeled pitted fresh plums (2-1/2 pounds)
2 packages (10 ounces each) frozen sweetened raspberries
10 cups sugar
1/2 cup bottled lemon juice
2 pouches (3 ounces each) liquid fruit pectin

In a large pot, combine the plums, raspberries, sugar and lemon juice. Bring to a full rolling boil over high heat, stirring constantly. Quickly stir in pectin; return to a full rolling boil. Boil for 1 minute, stirring constantly.
Remove from the heat; skim off foam. Carefully ladle hot mixture into hot pint jars, leaving 1/4-in. headspace. Remove air bubbles; wipe rims and adjust lids. Process for 10 minutes in a boiling-water canner. Yield: 6 pints.