Seedless Wild Blackberry Jam

Seedless Wild Blackberry Jam is a low-sugar cooked jam made with Pomona’s Pectin. Pomona’s Pectin contains no sugar or preservatives and jells reliably with low amounts of any sweetener. See below for where to buy. This recipe was created by Allison Carroll Duffy for Pomona’s Pectin. She says:

Making  seedless jam from wild berries isn’t hard to do, but it does take a little time and persistence . . .  the results are absolutely worth it. You’ll be rewarded with a luscious, smooth, spreadable jam.

Yield: 4 to 5 cups

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.

Seedless Wild Blackberry Jam Ingredients

3 quarts of blackberries
2 teaspoons calcium water
1 ¼ cups sugar
2 teaspoons Pomona’s Pectin powder

Note: Many wild blackberries are quite sour, but if you are using the sweeter wild blackberries found on the West Coast, add 2 Tablespoons lemon juice to the berries at the same time that you add the calcium water. You can make this recipe with cultivated blackberries. If they are quite sweet, however, you need to add 1/4 cup lemon juice when you add the calcium water to be sure they are acid enough for safe water bath canning.

Seedless Blackberry Jam Directions

1. Wash and rinse jars, lids, and screw bands. Set screw bands aside until ready to use. Place jars in boiling water bath canner with a rack, fill at least 2/3 of the way full with water, and bring to a boil. Boil jars for 10 minutes to sterilize (add 1 additional minute of sterilizing time for every 1000 feet above sea level), then turn down heat and let jars stand in hot water until ready to use. Place lids in water in a small pan, bring to a low simmer, and hold there until ready to use.

2. Pick through blackberries, discarding any stems. If blackberries look clean, rinsing them is optional.

3. Place berries in a large bowl and mash them thoroughly ( a potato masher works well for this).

4. Place a mesh strainer over a large bowl, and transfer mashed berries into the mesh strainer. Press the mashed berries through the strainer (the back of a wooden spoon, as well as clean fingers, work well for this), so that the blackberry pulp goes through the strainer into the bowl below, while the seeds remain in the strainer.


5. Measure out 4 cups of the blackberry pulp. (If you have any left over, you can use it for something else.) Pour the measured pulp into a large sauce pan. Add calcium water and stir to combine.

6. In a separate bowl, combine the sugar and pectin powder. Mix well and set aside.

7. Bring blackberry pulp to rolling boil over high heat. Add sugar-pectin mixture, then stir vigorously for 1 to 2 minutes, still over the highest heat, to dissolve pectin. Return jam to a boil, then remove from heat.

8. Remove hot jars from canner and fill jars with jam, leaving ¼ inch of headspace. Remove trapped air bubbles, wipe rims with a damp cloth, and put on lids and screw bands, tightening bands only to “fingertip tight” (until resistance is met, and then just the tiniest bit more).

9. Place jars in the hot water, on the rack inside the canner. (Make sure jars are upright, not touching each other or the sides of the canner, and are covered with at least 1-2 inches of water). Place the lid on the canner, return the canner to a rolling boil, and boil for 10 minutes. (Add 1 minute additional processing time for every 1,000 feet above sea level.)

10. Turn off heat and allow canner and jars to sit for 5 minutes. Then, remove jars from canner.

11. Allow jars to cool undisturbed for 12-24 hours. Then, confirm that jars have sealed. Remove screw bands from sealed jars, rinse off outside of jars if necessary, label jars, and store for later use.

Recipe by Allison Carroll Duffy. You can read her guest blog post about Wild Blackberry Jam here.

For more inspiring recipe ideas, see Preserving with Pomona’s Pectin: The Revolutionary Low-Sugar, High-Flavor Method for Crafting and Canning Jams, Jellies, Conserves, and More by Allison Carroll Duffy and the Pomona’s Partners, published by Fair Winds Press, June 2013, and available in paper or ebook everywhere books are sold.

Pomona’s Pectin is available at your local natural food store, food co-op, and many farm stands. Find it also at Sur La Table and a growing number of more conventional grocery stores with natural food sections (Wegmans, Hy-Vee, Rosauers, Nugget Markets, Coborns, Fairway, and others). If you can’t find a store near you on our store locator, you can order from our website or many other online sellers.

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21 thoughts on “Seedless Wild Blackberry Jam

  1. Can I use spices and vanilla with this recipe? I found a seedless BlackBerry jam recipe that includes spices and vanilla but I want to use this pectin. I’ve never use this pectin before so I want to make sure I don’t mess anything up…..

    • Hello Betsy,

      Yes, I would recommend using the same measurements, it may be a bit more of a firm set, as the seeds to add some natural pectin, but it should be just fine.

      Happy jamming!

  2. Hello,

    I really want to do this recipe for my co-workers for the holidays with a spiced sugar we sell (I work at a spice store). It’s sugar, vanilla beans, cardamom, mace, nutmeg, and cinnamon. Are any of these going to be problematic to can?

    Also I only have frozen berries, should I use the extra lemon juice in case they’re sweet? And would a food will be acceptable to use if I use the fine mesh?

    Thank you

    • Hello Samantha,

      Thanks so much for choosing Pomona’s for your holiday gift giving! Frozen berries are just fine, make sure you include the juices when you thaw them out for use. You should not need any additional lemon juice, the amount listed should do just fine. You can absolutely use the spiced sugar mix- it sounds spectacular!

      Happy jamming!

  3. hello,
    Could i use a pressure caner to avoid adding lemon juice to wild blackberries? I am planning to make syrup and can it in 1.5l jars.
    Will i run into some unknown problems by doing so?
    i thank you for your reply,

    • Hello Evelyn,

      Pressure canning is not a suitable method for processing jam & jelly. Because pressure canning produces very high heat, there is too great a risk of breaking the pectin down. When the pectin gets broken down, either you get no jell at all or an inadequate jell.

      The USDA does not publish any guidelines for successfully pressure canning jam & jelly, so we do not endorse that way of processing jam & jelly.

      The water-bath method is the most tested and most reliable method for canning jam & jelly, and you will need lemon juice for safe canning.


  4. I made this as my first jam ever. It turned out wonderfully! The only thing I would do differently would be to triple or quadruple the recipe the next time around.

    I used a food press with a wooden pestle to get the seeds out and I highly recommend them for removing the seeds but keeping the pulp. Mine is a heavy duty old one I found second hand, but I’ve seen similar ones for sale on Amazon.

    The canning rack that came with my canner has large gaps between it and the half pint jars tend to tip a lot. If I were to use pint jars instead, would the processing time change at all?

    Thanks for a fantastic recipe!

    • Hi Carla,
      Congratulations on a successful first jam — we love hearing that! And thanks for sharing about your food press and wooden pestle. That could be helpful information for others.

      It is fine to put the jam in pint jars. The processing time is the same as half-pint jars. Our one caution with pint jars and low-sugar jam is that low-sugar jam doesn’t normally keep as long in the refrigerator, once opened, as high-sugar jam. So you want to be sure you can eat up a pint in 3 to 4 weeks.

      Here is what we say about doubling, tripling, and quadrupling recipes on our FAQ page, Section 3:

      Can I double or triple a Pomona’s cooked recipe? Are there any potential limits or pitfalls when doubling or tripling a recipe?

      Yes, you can double or triple a Pomona’s cooked recipe. Be sure to double or triple all of the ingredients in the recipe.

      Potential Limits and Pitfalls when doubling or tripling a recipe:

      1. You must have a water-bath canner that is large enough to hold ALL of the jars you are filling. It is not safe canning practice to let some of the filled jars sit on the counter while you water bath others. As soon as all the jars are filled and have their lids on, they should ALL go into the boiling water in the canner.

      2. You must have a pot that is large enough to hold all of the fruit in the recipe plus the added ingredients, with enough extra room to stir vigorously while the mixture is boiling and not have the contents spill over.

      3. You must have a stove that is powerful enough to bring the fruit mixture to a full boil and to bring it back to a full boil in a few minutes after you stir in the pectin-sweetener mix. If the fruit mixture with the pectin in it takes too long to return to a full boil, the pectin can be de-activated and you will get runny jam.

      4. You must have a stove that is powerful enough to bring a large water bath canner with all of the filled jars in it back to a rolling boil in a few minutes so as not to de-activate the pectin by extended exposure to heat while waiting for the boil to come back.

      We do not recommend quadrupling a recipe unless you are specifically set up for it!

      Thanks again for writing to us — and happy jamming!

      • Thanks so much for your response! I should have looked at the FAQ page first.

        I can’t wait to give my jam to family and friends. I LOVE that I can use way less sugar with Pomona’s.

    • You can cover your canning rack with an ordinary dish towel. This may help fill in the extra spaces and keep the half-pint jars stable.

    • Dear Jan,
      Yes, you could use a juicer to remove seeds if your juicer will do that for you. If you end up with juice and no pulp, you would need to follow the recipe on our direction sheet for Blackberry Jelly. Juice requires more pectin to jell than fruit pulp does. That means for 4 cups of juice, you need 4 teaspoons of pectin powder and 4 teaspoons of calcium water.

      Also remember that if you have sweet blackberries, you need to add 1 Tablespoon of lemon juice per cup of juice (1/4 cup per 4 cups of juice).

      I hope this helps — and happy jamming!

  5. I freeze berries as I pick, to preserve them until fall. (I prefer to jam in the cool of autumn.) Freezing ruptures the berry cells, seemingly producing more juice. After defrosting, I run the berries thru a blender, then work them thru a fine sieve. Seeds and very little pulp are left behind. It works for black raspberries (for those determined enough to pick them!), as well as blackberries and raspberries.

    • Thanks for sharing your method, Jen. I’m getting ready to pick the wild blackberries that grow near us on the east shore of San Francisco Bay. I hope I’ll get enough to freeze and I plan to give your method a try!

    • Exactly! I have my freezer nearly 1/4 full of blackberries and will wait until the weather cools off. We average 88% daytime humidity in July and August which takes all the pleasure out of jam making. Fans, AC turned low doesn’t cool down the kitchen.

  6. Can I steep some tarragon (or Mexican tarragon) sprigs into the pulp while it heats up and then remove the tarragon before filling the jars? The idea is to steep the tarragon-flavor into the jam. Are there any problems with adding some lemon zest to this recipe as well?

    • Dear Alan,
      It is fine to steep some tarragon into the blackberry pulp and then remove it before filling the jars. It is also fine to add some lemon zest to this jam.

      Thanks for using Pomona’s and happy jamming!

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