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.

Share this:

6 Responses

  1. Allison
    | Reply

    Hello! I made two batches of this jam and it is by far the best tasting and most attractive jam of the many recipes I’ve tried this year. I’m wondering whether it would be safe to adjust the recipe to use peaches in place of the plums and blackberries or blueberries in place of the strawberries, and also to omit the rosemary for this version. If so, can the proportions of peach to berry be adjusted as well or is it safest to stick with equal parts? Thank you!

    • Shelby Collings
      | Reply

      Wonderful!! Yes, those substitutions can be made. You may sub the plums for peaches, and the strawberries for black or blueberries. And you may omit the rosemary. We would suggest keeping the proportions the same.

      happy jamming!

  2. 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 😊

Leave a Reply

Your email address will not be published. Required fields are marked *

Recipe Rating