blackberry on a silver sppon on a marble counter top

Blackberry Jam


5 from 2 votes
Our classic Blackberry Jam is one for the books. It has been approved from the sweetest grandma to the grizzliest lumberjack, and all those in between agree, it is sure to delight your senses.
Feel free to use other sweeteners that measure like sugar or honey in this recipe. For example, you can use Stevia in the Raw or another Stevia product that measures like sugar, or Splenda that measures like sugar. You can also use a different liquid sweetener, like agave or maple syrup. Pomona’s Universal Pectin contains no sugar or preservatives and jells reliably with low amounts of any sweetener.


If you’re not sure if your jam is sweet enough, taste it after the pectin is dissolved and jam has come back up to a boil. Not sweet enough? Add more sweetener and stir 1 minute at full boil.
Servings 5 cups


  • 4 cups mashed blackberries about 8 cups whole blackberries
  • ¼ cup lemon juice bottled, if berries are sweet
  • 2 teaspoons calcium water see step #1
  • ½ cup up to 1 cup honey or ¾ cup up to 2 cups sugar
  • 2 teaspoons Pomona’s Pectin powder 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 simmer. Turn off heat and keep lids in hot water until ready to use.
  • Wash, remove any stems/debris and mash blackberries. Measure fruit into sauce pan.
  • Add lemon juice and calcium water and mix well.
  • Measure sugar or room temperature honey into a bowl. Thoroughly mix pectin powder into sweetener. Set aside.
  • Bring fruit mixture to a full boil. Add pectin-sweetener 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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16 Responses

  1. Christine
    | Reply

    Made this today with freshly picked blackberries and it was delicious! I am confused, though, about the lemon juice. When I read the recipe, I understood it as “use lemon juice if the berries are sweet,” which mine weren’t particularly. I made half recipe and used the juice of one juicy lemon. I didn’t measure but I’m guessing it was a good amount but not quite an eighth of a cup. All this being said, The more reviews and recipes I read on this website, it sounds like the lemon juice is necessary for pH. One place it even said that someone should throw away the jam since they forgot the lemon juice as it wouldn’t be safe. I made freezer jam if that makes any difference. Can you please help me understand this?

    • Shelby Collings
      | Reply

      Hello Christine,
      Lemon juice is needed if your blackberries are sweet, but if they are tart, it is not necessary. When you are making freezer jam, the pH is inconsequential, so you are good to go!

      • Christine
        | Reply

        Thanks so much!

  2. Corinne
    | Reply

    Can’t wait to try this simple recipe – Can you use fresh lemon juice instead of bottled?

    • Shelby Collings
      | Reply

      Yay! We recommend using bottled lemon juice because it has a guaranteed pH.

  3. Mara
    | Reply

    Great recipe! I love how little sugar/honey it needs and how the full delicious flavour of the blackberries comes through. It jelled up really nice. This is now my go-to recipe for blackberry jam.

  4. Patty
    | Reply

    Blackberry jam turned out great!! I also made pepper jelly and it jelled up really fast!

  5. Tiffany
    | Reply

    Is this the same recipe that would be used for Marionberries?

    • Shelby Collings
      | Reply

      Yes, it sure is!

  6. Renee
    | Reply


    Can I use frozen blackberries for this recipe? If so, do I need to let them thaw first, and then measure them? Or, do I measure them while still frozen? Thank you.

    • Shelby Collings
      | Reply

      You sure can Renee! You will want to allow them to thaw, mash them up, and then measure them out.

      Happy jamming!

  7. Sarah
    | Reply

    How would you adapt this recipe for a Ball jam maker machine? The sugar-pectin goes in at 4 minutes, and the machine keeps going for another 15 minutes. Will this stop the Pomona pectin from working? Or is it okay?

    • Shelby Collings
      | Reply

      Yes, you can use Pomona’s to make jam in your electric jam maker or bread machine. You will need to follow a Pomona’s recipe and the basic directions for Cooked Jam – Low Sugar or Honey for it to work properly.

      You need to mash & measure the fruit into a bowl. If our recipe is too big for your machine, then you can do a half recipe. Add the calcium water & lemon juice (if called for) and stir well. Then mix the pectin into the sugar (or other sweetener) and then add the pectin-sweetener mix into the bowl of fruit and stir well. Then put the bowl of jam mixture into the machine and turn it on.

  8. Marika Berman
    | Reply

    Hello, I made blackberry jam using the recipe in the insert. It came out perfect. But it was not sweet enough for my bf, so I doubled the sugar (according to his recipe in the past). But then the jam came out really runny. In the next batch, I added extra pectin and calcium water and it’s still too runny (though better). Any suggestions on how to fix the problem with full amounts sugar? I am using 4 cups of fruit and 5 cups of sugar. Thank you in advance!

    • Shelby Collings
      | Reply

      Hello Marika,

      Thanks so much for reaching out! Pomona’s Pectin will only jell in a low sugar environment. (4 cups mashed fruit to less than 2 cups sugar). We would recommend following the recipe as you did with your first batch, and once the sugar/pectin is dissolved you can then add your additional cups of sugar. 😊

      Happy jamming!

      • Patti Welday
        | Reply

        I wish I had read this post prior to my jalapeño jelly project I just finished. Lids are still popping as we speak. However, the batch looked a little runny… I think it’s because I doubled the recipe. I hope it will gel better as it cools from water bath. I have been canning a lot but have never used Pomona pectin before…. I am learning!

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