Make low-sugar blackberry jam to preserve the goodness of summer all year round! Sometimes, you need a good old-fashioned blackberry jam to make the summer feel complete, and this low-or-no-sugar recipe is a great way to make it healthy!
![Jars of dark purple blackberry jam on a cloth with fresh blackberries surrounding.](https://www.growforagecookferment.com/wp-content/uploads/2024/07/low-sugar-blackberry-jam-featured.jpg)
A Blackberry Summer
We’ve all had “zucchini summers” or the like in our gardens when the season’s conditions seem perfect to produce a major abundance of a certain fruit or vegetable.
I always try to remember this when we have extra hot summers. Because as miserable as the heat might seem sometimes, it always means we will have an abundant blackberry summer!
There’s probably not another berry I love more than blackberries, and their sweet and tart juiciness is 100% worth every hot day. The sun infuses the best flavor into late-summer blackberries.
When it’s a blackberry summer, I always make blackberry kombucha, blackberry mead, peach blackberry cobbler, and at least one pear and blackberry crisp.
When blackberries are still left after that, I’ve learned the best ways to freeze all types of berries. However, one of the best ways to preserve blackberries in their abundance is to make blackberry jam.
There’s something so old-fashioned and lovely about blackberry jam. It brings back memories of summer cabins where we’d spread it on rolls with butter for perfect dinnertime sweetness.
Let’s gather some blackberries and get jammin’!
Blackberry Jam Recipe
This blackberry jam recipe is low-sugar with a no-sugar option, making it a perfect healthier spin on a tried-and-true favorite. This recipe will make 4-5 half-pint jars, but it’s super easy to increase.
Ingredients
Blackberries: Foraged blackberries or frozen are both okay to use in this recipe.
Lemon juice: I prefer freshly squeezed lemon juice!
Calcium water: Made from the packet in Pomona’s Pectin box.
Sugar: I use organic cane sugar. You can substitute it with honey, maple syrup, or agave. There is also a no-sugar option. If you want stevia to sweeten blackberry jam, try a pinch at a time. It doesn’t need much!
Pomona’s Pectin: Blackberries have some natural pectin, but to be sure my low-sugar jam sets, I always use Pomona’s Pectin since the natural amounts will vary.
Note: Pomona’s Pectin comes with two packets. The smaller one with calcium powder is needed to make the calcium solution with water. The larger packet has pectin powder which is added to the sugar while making this jam.
How to Make Blackberry Jam with Low-Sugar
First, prepare your boiling water canner for a water bath method.
Put the canning rack at the bottom of a large pot and heat the jars in simmering water until it’s time to use them. Wash the lids in warm soapy water and set them aside.
Mix the calcium water as per Pomona’s Pectin instructions.
Gently rinse the blackberries in cold water and then mash them in a large bowl. I like to use a potato masher for this, it works well.
Measure out 4 cups of mashed blackberries. If you have extra, freeze them for another use, or make more jam!
Put the mashed blackberries in a saucepan, add the lemon juice and calcium water, and mix well.
Then, use a small bowl to combine the sugar and pectin powder and mix them thoroughly.
Bring the blackberry mixture to a full boil over high heat. Then slowly add in the sugar-pectin mixture, making sure to stir it constantly.
Continue stirring vigorously for 1 to 2 minutes to dissolve the pectin as the jam returns to a boil. Once the jam returns to a full boil, remove it from the heat.
For No-Sugar Blackberry Jam
- Replace the sugar with ¾ cup water or juice (apple juice works well).
- Bring the water/juice to a boil, put it into a blender or food processor with the pectin powder, and vent the lid.
- Blend for 1-2 minutes until all of the powder is dissolved.
- Add this mixture instead of sugar-pectin to the boiling blackberries in the above recipe.
Process for Canning
Then, use a jar lifter to place the prepared jars onto a wooden cutting board or kitchen towel. Using a funnel over the jars, ladle the jam into them.
Make sure to leave about 1/4 inch of headspace in each jar and remove any air bubbles. Wipe the rims of the jam jars.
Then center a lid onto each jar and apply the band, adjusting it closed to fingertip tight.
Place the filled jars with lids into the boiling water canner, making sure the water covers them by at least 1-2 inches.
Process the jars in a boiling water bath for 10 minutes. Turn off the heat, remove the pot lid, and let the jars sit inside for 5 minutes.
Use a jar lifter to remove the hot jars and let them cool for 12 to 24 hours.
Lastly, check the lids to make sure they are all sealed. They should not flex when the center is pressed. Now, it’s time to enjoy summer year-round with tasty low-sugar blackberry jam!
Use and Store Summer Jam
This sweet and juicy blackberry jam with low or no sugar is absolutely late summer in a jar, with its deep purple color and sun-ripened flavor. It’s absolutely delicious!
Plus, it’s shelf-stable, providing a little bit of late summer sun into your system whenever you need the feeling of a warm sunny afternoon.
Spread it on a fresh baked roll, with cream cheese on a sourdough bagel, in thumbprint cookies, or to spruce up your morning toast! Have you tried jam in grilled cheese? Now is the time!
Honestly, you can’t go wrong with blackberry jam. It really goes on anything you’d eat jam on, but it gives it a bit of sunshine and the deep earthy late summer vibe of blackberries. For the best!
This jam is shelf-stable for up to two years or more. Once opened, the jam will last beautifully in the refrigerator for several months.
More Jam and Jelly Recipes
- Low-Sugar Raspberry Jam
- Lilac Jelly
- Strawberry Jam Low-or-No-Sugar
- Dandelion Jelly: Low Sugar or Honey
- No Sugar Peach Jam
- No Sugar Blueberry Jam
- Wild Violet Jelly
Blackberry Jam: Low-Sugar or No-Sugar
Equipment
- 4-5 Half Pint Jars
Ingredients
- 8 cups blackberries
- ¼ cup lemon juice
- 2 teaspoons calcium water from the Pomona’s Pectin box
- 1 cup sugar
- 2 teaspoons Pomona’s Pectin
Instructions
- Prepare your boiling water canner for a water bath method. Put the canning rack at the bottom of a large pot and heat the jars in simmering water until it’s time to use them. Wash the lids in warm soapy water and set aside until ready for use.
- Mix the calcium water as per Pomona’s Pectin instructions.
- Rinse the blackberries and mash them in a large bowl (a potato masher works well).
- Measure 4 cups of mashed blackberries (saving any extra for another use) and put in a saucepan. Add the lemon juice and calcium water and mix well.
- In a small bowl, combine the sugar and pectin powder and mix thoroughly.
- Bring the blackberry mixture to a full boil over high heat, then slowly add the sugar-pectin mixture, stirring constantly.
- Continue to stir vigorously for 1 to 2 minutes to dissolve the pectin as the jam comes back up to a boil. Once the jam returns to a full boil, remove it from the heat.
- Use a jar lifter to place the jars onto a wooden cutting board or kitchen towel and ladle the hot jam into the funnel to pour the jam into the prepared jars. Leave about 1/4 inch of headspace and remove any air bubbles.
- Wipe the rims of the jam jars and center a lid onto each jar and apply the band, adjusting to fingertip tight. Place the filled jars into the boiling water canner, making sure there is 1-2 inches of water covering the jars.
- Process the jars in a boiling water bath for 10 minutes. Turn off the heat, remove the pot lid, and let the jars sit inside for 5 minutes.
- Use a jar lifter to remove the hot jars and let them cool for 12 to 24 hours. Check to make sure the lids are all sealed, they should not flex when the center is pressed.
To Make No-Sugar Blackberry Jam
- Replace the sugar with ¾ cup water or juice (apple juice works well).
- Bring the water/juice to a boil and then put it into a blender or food processor with the pectin powder and vent the lid.
- Blend for 1-2 minutes until all of the powder is dissolved.
- Add this mixture instead of the sugar-pectin mixture to the boiling blackberries in Step 6 of the recipe above.
Notes
- Pomona’s Pectin comes with 2 packets. The smaller one with calcium powder is needed to make the calcium solution with water. The larger packet has pectin powder that is added to the sugar while making this jam.
- Honey, maple syrup, or agave nectar can be substituted for the sugar.
Can I ask what the calcium water is for? I’m in the UK and have never heard of it. We buy powdered or liquid pectin but it doesn’t come with calcium water.
Hi Jane. The calcium water comes in the box with Pomona’s Pectin. It’s needed to cause the pectin to gel.