Reduced-Sugar Blackberry-Plum (or Raspberry-Plum) Freezer Jam 3.500
Canning Jul 6, 2005

Nancy Baggett likes to combine plums with berries because they add fruitiness and vibrant color, but no seeds. Plums are also rich in pectin, so they help ensure that the jam will jell well.

Servings: 3.5 cups
  • 2 1/3 cups blackberries or red raspberries
  • 2 cups (1 to 1 1/4 pounds) slightly underripe purple or red plums, pitted and chopped into 1/2-inch pieces
  • 2 tablespoons water
  • 2 to 2 1/2 tablespoons lemon juice (use 2 1/2 tablespoons for very ripe, sweet berries)
  • 1/2 teaspoon finely grated lemon zest
  • 2 1/3 cups sugar
  • 2 tablespoons powdered less- or no-sugar-needed pectin, such as Sure-Jell or Ball Fruit Jell


Place several metal tablespoons in the refrigerator to use later in checking the jell of the jam. Have 3 or 4 eight-ounce jars ready.

In a large shallow bowl, crush the berries with the bottom of a wide-bottomed jar. Add the plums, water, lemon juice and zest and 1 cup sugar, stirring until well blended. Let stand about 5 minutes, until the fruit juices begin to flow. Set aside.

In a large, wide-bottomed nonreactive pan or deep-sided skillet on medium-high heat, combine the remaining 1 1/3 cups sugar and the pectin until well blended and no lumps remain. Add the fruit mixture, stirring to combine well.

The mixture will come to a full, foamy boil; cook, stirring constantly, for 8 minutes or until the plum skins loosen, the berries are tender and the jam is slightly thickened. If the mixture still appears runny after 7 minutes, drop about a teaspoon of it onto one of the chilled metal tablespoons and let it cool for 15 seconds. If it immediately runs off instead of jelling lightly and clinging to the spoon, continue cooking about 1 minute longer, then check using another chilled tablespoon.

As soon as the mixture jells just enough to cling to the spoon, it is done. (It will continue to jell and thicken further upon standing.) Immediately remove from the heat. Skim off and discard any foam from the jam's surface.

Ladle the jam into jars, leaving 3/4-inch headroom to allow for expansion during freezing. Wipe any drips from the jar rim and threads; screw on the lids securely. Let stand until the jam is barely warm. If lids seem loose after cooling and contracting, check and tighten further, but not so much that the seal is broken. Refrigerate for 24 hours. May refrigerate for up to 3 weeks or transfer to the freezer for up to 1 year.

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Recipe Source

Adapted from cookbook author Nancy Baggett.

Tested by Nancy Baggett.

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