slices of watermelon on a white table

Watermelon Jam


Watermelon Jam is a low-sugar cooked jam made with Pomona’s Universal Pectin. Pomona’s Pectin contains no sugar or preservatives and jells reliably with low amounts of any sweetener.


If you want to make jelly with only the juice of the watermelon, see our Watermelon Jelly recipe.
Servings 5 cups


  • 4 cups watermelon puree use a seedless watermelon or see Step 3 below
  • 4 teaspoons calcium water see step #1
  • ½ cup lemon juice bottled
  • ¾ cup up to 2 cups sugar
  • teaspoons Pomona’s Pectin mixed with sweetener


  • Before you begin, prepare calcium water.
    To do this, combine ½ teaspoon calcium powder (in the small packet in your box of Pomona’s pectin) with ½ cup water in a small, clear jar with a lid. Shake well.
    Extra calcium water should be stored in the refrigerator for future use.
  • Wash jars, lids, and bands. Place jars in canner, fill canner 2/3 full with water, bring to a boil. Turn off heat, cover, and keep jars in hot canner water until ready to use. Place lids in water in a small sauce pan; cover and heat to a low boil. Turn off heat and keep lids in hot water until ready to use.
  • If watermelon is seedless, puree fruit to a pulp in blender or food processor. If watermelon has seeds, remove the seeds prior to pureeing.
  • Measure puree into sauce pan.
  • Add calcium water and lemon juice, and mix well.
  • Measure sugar into a bowl. Thoroughly mix pectin powder into sugar. Set aside.
  • Bring fruit to a full boil. Add pectin-sugar mixture, stirring vigorously for 1 to 2 minutes to dissolve the pectin while the jam comes back up to a boil. Once the jam returns to a full boil, remove it from the heat.
  • Fill hot jars to ¼” of top. Wipe rims clean. Screw on 2-piece lids. Put filled jars in boiling water to cover. Boil 10 minutes (add 1 minute more for every 1,000 ft. above sea level). Remove from water. Let jars cool. Check seals; lids should be sucked down. Eat within 1 year. Lasts 3 weeks once opened.

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2 Responses

  1. Holly Masters
    | Reply

    What size(s) of jar do you use for this recipe? Thank you!

    • Shelby Collings
      | Reply

      Hello Holly,

      We would recommend 4-8oz jars. Happy jamming!

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