bowl of strawberries on a kitchen towel on a white table

Plum-Strawberry-Rosemary Jam

This recipe was adapted and contributed by Vivian Solomon, who was inspired by a recipe in The Blue Chair Jam Cookbook by Rachel Saunders. Plum-Strawberry-Rosemary 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.
Vivian says: “The Plum-Strawberry-Rosemary Jam is a big hit!” It came out perfectly jelled with deep color and a bit of tartness.


*IMPORTANT* This is a two-day jam. The berries and plums are prepared and mixed with some of the sugar, then macerated for 12 or so hours.
Options from Mary Lou: I made this jam recently, with a few small changes that I want to share. I used Flavorosa Plums, which are also called Pluot or Plumcot, as that is what was available at my local farmers’ market.
I only had 1½ cups of mashed plums. To make up for the missing ½ cup of mashed plums, I used 2½ cups of mashed strawberries, also from my farmers’ market. The strawberries were sweet, but the plum skins were quite bitter, so I put some plum skins in but not all.
I macerated the fruit in ½ cup of sugar for 9 hours, but then stirred the pectin into only ½ cup of sugar – for a total in the jam of 1 cup of sugar, not 2 cups. And finally, I added a small pinch of salt (never more than 1/8 teaspoon) to the fruit mixture and I steeped the rosemary in the fruit for 2 minutes.
I am happy to report that this may be the most delicious jam I have ever tasted! My next favorite is Merry Mulled Merlot Jam, recipe created by Carey Nash.
The texture, the color, and the taste of Plum-Strawberry-Rosemary Jam are absolutely wonderful. Thank you Vivian!
Servings 5 cups


  • 2 cups mashed strawberries
  • 2 cups sweet plums (I used Santa Rosa) unpeeled, pitted, chopped, and mashed
  • 2 cups sugar divided
  • 3 teaspoons calcium water see step #1
  • 2 Tablespoons lemon juice bottled
  • teaspoons Pomona’s Pectin mixed with sweetener
  • 2 10inch sprigs of fresh rosemary


  • 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.
  • Prepare strawberries by washing, hulling, and mashing.
  • Prepare plums by washing, pitting, cutting into small dice, and mashing. Don’t peel.
  • Measure out 2 cups of mashed strawberries and 2 cups of mashed plums into a bowl or container with a lid. (If you have extra, save for another use.) Add ½ cup of the sugar and mix well. Cover and put in refrigerator to macerate for 12 to 14 hours.
  • The next day, when ready to make the jam, 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.
  • Transfer macerated fruit into a sauce pan; add calcium water and lemon juice, and mix well.
  • Measure remaining sugar (1½ cups) into a bowl. Thoroughly mix pectin powder into sugar. Set aside.
  • Bring fruit mixture 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.
  • Lay the rosemary sprigs into the hot jam, and gently mix. Allow to steep, covered, for 1-2 minutes. After steeping, taste if you like – the rosemary flavor will not be as strong in the finished jam as it is at this stage. Remove the rosemary sprigs, and stir the jam.
  • 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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4 Responses

  1. Mindy Bostick
    | Reply

    Is macerating the fruit in sugar overnight absolutely necessary? I have very ripe, sweet plums and strawberries that I ran through the food mill and froze. Also can honey be used instead of sugar?

    • Shelby Collings
      | Reply

      No, you may choose to skip that step. Yes, it sure can (it measures 1/2 the amount of sugar).

      Happy jamming!

      • Susan
        | Reply

        Delicious flavors…I took Mary Lou’s advice and used a total of 1 cup sugar and 1/16th tsp of salt and actually, think I might use even less sugar and more salt next time. Rosemary adds a lovely and subtle note. I used a 2 c strawberries and 2 c of a combo of 2 types of pluots and 1 type of peacotum.
        One thing that I did differently was held back to 2 tsp of pectin and actually feel like I could have used a lot less because there seemed to be a fair amount of pectin activated from the fruit itself.
        Q1: Any thoughts on this, and what would be the rock bottom minimum of pectin that could be added, factoring in 4 cups of fruit and 1 cup of sugar?
        Q2: Has anyone tried honey instead of sugar in this recipe, and if so what was the verdict? Did the honey flavor overpower the fruit flavors?

        • Shelby Collings
          | Reply

          Wonderful Susan!

          Q1: We would say that 1 tsp Pomona’s Pectin would be the smallest amount that we would recommend using for this recipe.

          Q2: We have not, but maybe other followers have 😊

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