Low-Sugar Blackberry Jam Canning Recipe with Pomona’s Pectin
04. May 2026
It’s been over ten years now since I decided to start making my own jams and jellies. Back then, I wasn’t growing any fruit in my backyard yet, so I relied on the local farmers market and a few nearby you-pick farms to source what I needed. Growing up, I watched my grandma make jelly from the plum tree in her yard and blackberry jam from the berry patch that grew along the edge of the woods. I wanted to carry that tradition forward in my own way.
So I picked up a canning book, listened to a few food preservation podcasts, and even took an online canning course to make sure I was doing things safely. One thing became clear pretty quickly. When it comes to canning, you don’t wing it. You follow tested measurements so everything is both shelf stable and safe.
But I also learned something else. Traditional jam recipes use a lot of sugar to gel up the fruit. I didn’t love the results. I was really trying to cut back on eating so much sugar. And the jam was so sweet that the fruit flavor got lost. It tasted more like syrup than fruit. I couldn’t reconcile taking these healthy, organically grown local berries packed with nutrients and then adding an excessive amount of sugar.
Switching to Low-Sugar Pectin
It was exactly what I had been looking for.
The first time I used it, I was hooked. The flavor of the fruit actually came through. It tasted like blackberries again, not candy.
Growing My Own Blackberries
Fast forward about 7 years, and my husband and I planted thornless blackberries in the backyard on a trellis we built. That changed everything. Now instead of sourcing fruit, I can walk outside and pick it myself. We grow two thornless varieties. One is called Natchez, which produces very large berries early in the season. They’re a heat-tolerant variety with excellent flavor.
We also grow Ouachita which bears a little later and produces medium sized berries in higher quantities. Ouachita is also known for excelling at disease resistance.
The fact that the plants are thornless is a big deal. If you’ve ever picked wild blackberries, you know what I mean. Growing up in the country, blackberry picking meant scratches up and down your arms after reaching into thorny thickets.
These thornless plants are a completely different experience and picking berries is something I actually look forward to.
Once berries start ripening, I go out daily and pick a bowl full of the ripest berries on the plants. I wash them by soaking them in water to drive out all the tiny insects and store them in the freezer in freezer bags. That allows me to build up enough for a batch of jam without needing everything to ripen at once.
The key is getting to them before my husband does. When he does the picking, very few make it into the house.
If you don’t have the space or ability to grow your own, visiting a you-pick farm not only helps your local farmer, but it’s also a great family activity to enjoy in spring and summer.
Low-Sugar Blackberry Jam Recipe
This is the exact method I use with my own berries. This comes straight from the recipe inside the Pomona Pectin box. Each box contains recipes for making low-sugar jams and jellies from a variety of fruits.
Preservation method: Water bath canning (or steam canning)
Difficulty level: Easy to moderate
YIELD: Makes about 5 half pint jars
Head space: 1/4 inch (.635 cm)
Processing Time: 10 minutes
- 4 cups mashed blackberries (about 8 cups of whole blackberries)
- 2 teaspoons Pomona's Universal Pectin powder
- 2 teaspoons calcium water (the powder is included in the box with instructions on mixing it with water, see info below)
- 1/4 cup bottled lemon juice
- 3/4 cups sugar (see notes below, you can use 1/2 to 1 cup of honey OR 3/4 to 2 cups sugar)
Traditional jam canning recipes, like those from Ball Canning, often call for a 1:1 ratio of fruit to sugar. So we’re talking 4 cups of sugar for the same amount of fruit to get a proper set! That’s a huge difference compared to using Pomona’s Pectin. With Pomona’s Pectin, you have the ability to adjust not only the amount of sugar, but also the kind of sweetener. For this blackberry jam recipe, you can use 1/2 to 1 cup of honey OR 3/4 to 2 cups sugar. You can start with a smaller amount of sugar, then adjust to your taste.
Also, I always use bottled lemon juice. It ensures consistent acidity, which is important for safe canning.
In a separate bowl, thoroughly mix the pectin powder into your sugar. This helps prevent clumping when making the jam. Mix thoroughly and set aside.
Heat the fruit mixture to a full boil.
Stir in the pectin and sweetener mixture a little at a time. Stir constantly for 1 to 2 minutes as it returns to a full boil.
Let prepared jars stand at room temperature for 12-24 hours. After the jars cool, check seals by pressing the centers of lids with your finger. If the lid springs back, the lid is not sealed and refrigeration is necessary.
Affix CanningCrafts’ labels and write dates on jars. Store unopened jam in a cool, dry place for up to 1 year. Once opened, keep in the refrigerator and use within about three weeks.
*Altitude
Living at a higher altitude affects home canning recipes, just as it does baking recipes. Many people are unaware that they live at a high altitude. If you live at a high altitude, you’ll need to increase either your processing time or processing pressure. Most canning recipes state this info for elevations of 0 to 1,000 feet above sea level. If you aren’t sure what your elevation is, get more info from the National Center for Food Preservation. Or call your local extension office if unsure.
A Few Notes from My Kitchen
Blackberries are naturally seedy, and I don’t strain them. The seeds soften during cooking and don’t bother me. If you prefer a smoother jam, you could strain them out before cooking but I find this to be a tedious process and you just get mostly juice. You can completely strain the mixture and retain the juice if you want to make jelly instead of jam. There are also recipes for that in the pectin box requiring double the amount of pectin and calcium water.
If you’re gifting jars or just want to make them feel a little more special, this is where you add your decorative labels from CanningCrafts. This makes a simple jar of jam beautiful and something worth sharing.
Why I Return to This Recipe Each Year
This jam recipe checks all the boxes for me. It’s lower in sugar, it tastes like real fruit, and it connects me back to a memory from childhood.
But now it’s also tied to my own backyard garden. It’s so satisfying to walk outside, pick berries, and turn them into something you can enjoy months later. And once you taste blackberry jam like this, there’s really no going back.
Want more low sugar jam recipes? Both of our recipes below use Pomona’s Pectin
Honey Pear Jam Canning Recipe
Low Sugar Chocolate Cherry Jam Canning Recipe
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