Here’s an easy recipe for a delicious jam with low sugar that actually tastes like blackberries!
Blackberries and chia seeds are the base of this low-sugar blackberry jam recipe. Blackberries bring the flavor and the chia seeds thicken it up. It takes way less time than a regular jam.
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Blackberry foraging time is one of my favorite times of the year! We have this little secret spot we go to near a river and there are tonnes of juicy blackberries. I can’t grow bulk amounts of berries in my shadier garden so I make the most of harvesting what’s out there to freeze for over the colder months.
Last year we foraged over 10kg of berries!
So, for that reason, this is a low-sugar blackberry jam recipe, but it can absolutely become a homemade jam of whatever berries you’ve got and love!
Blackberry season
Late summer is blackberry season. Wild blackberries grow in abundance here in New Zealand, and I’m sure over other parts of the world it’s the same. They are a real invasive pest plant though, so they are often sprayed with herbicides.
For this reason, if you’re planning on foraging, make sure you find a spot where you know that they have not been doused in chemicals. The fresh blackberries we harvest come with extra little caterpillar friends so we soak them in a large bowl of salty water for about 30 minutes to encourage them to crawl out.
I’m not sure if salted water works any better than plain water, but that’s how my dad always did it so that’s what I do now! Then they can be picked off as we see them. It’s a bit of a process but hey, they’re free berries so I’m not complaining!
Chia seeds
Chia seeds are the magic ingredient that provides the thickness in this low sugar blackberry jam recipe. Usually, regular jam is thickened using pectin which along with acidity and sugar helps the jam get to the gel stage and set.
This recipe is a blackberry jam without added pectin. Traditional jams need a lot of added sugar and this can really mask the taste of the fruit itself. It also means it’s not very healthy.
In this low sugar version, the flavor of the fruit really comes through. When chia seeds react with liquid, their outer shells swell up into this jelly-like texture and this is a good thing! It's what provides the thickness without adding much sugar (or any sugar) at all.
The sweetener
This easy blackberry jam recipe uses only the amount of sugar or sweetness you actually want to taste, and it doesn’t have to be from refined sugars. You could use whatever sweetener you like. Or, if your fruit is sweet enough on its own you could even miss the sugar out completely. Sweetener options can include.
- White sugar
- Coconut sugar
- Honey
- Stevia
- Apple syrup
- Maple syrup
The method
I use around 450 grams of blackberries for every 500ml (pint) jar or for 2 x 250ml jars (half pint jars).
Fresh berries (or frozen) are added to a large pot over medium heat, along with a tablespoon of lemon juice. Once the berries start heating up they will release their juices. Keep stirring it as they do so.
When the mixture starts to simmer and the berries break apart, add in a pinch of salt and your sugar or sweetener of choice. You can use a potato masher or fork to help break the berries down if you like.
I wait until at least this stage because it is easier to taste it to see how much sweetness you’ll need. You might prefer more or less sugar depending on personal tastes.
Now the mixture needs to simmer for around 15-20 minutes until most of the excess liquid has been reduced. If using frozen berries it may take a little longer. It will still be runny though while it’s hot and before the chia seeds have been added in.
Taste it again at this point and see if it needs any more sweetener.
While the jam is simmering, clean and sterilize the jars you are using by giving them a soapy wash and rinsing well. Place the washed jars upright on a baking tray and put them into a low oven at 120C/248F for about 15 minutes or until jars are completely dry.
Once simmered down, remove the jam from the heat and stir through chia seeds. Stir them at the moment they hit the jam, or they’ll clump together. It will start to thicken within about 5 minutes and will continue to do so as the jam cools later on.
Carefully pour the hot jam into the hot jars, clean the jar rims and seal the jars. Let them cool right down to room temperature. Store the jam in the fridge or freeze it to make blackberry freezer jam.
As it is a low sugar jam, it will last for only about a week in the fridge or up to 3 months in the freezer. Alternatively, it can be preserved via a hot water bath. This method will allow it to store unopened for up to 6 months. Once opened, store in the fridge and use within a week.
Water-bath canning
To store the blackberry chia jam long-term, take a large saucepan and place a rack or something similar in first, then fill it halfway with hot water. Lower the hot jars in the water. (If you don’t have a rack, you could use the lids of your spare preserving jars instead.
This stops the jars from sitting directly on the bottom of the pan.) If possible, add more water so the jars are covered by about 2cm worth of water.
Bring the water to a rolling boil over high heat and once it is boiling, keep it at a rolling boil for 10 minutes. Take the pan off the heat and let the jars sit for 5 minutes before carefully removing them. Preserving tongs from a kit like this works a treat for this!
Once the jars are cooled, check the top of the jar to see that the lids are concave and remove any preserving jar bands if that’s what you’ve used. Label the jars and store them in a cool, dark place for up to 6 months.
Serving
There are many delicious ways to serve this homemade blackberry jam. Try
- Spreading it on sourdough toast
- Swirled in ice cream or yogurt
- Over pancakes and waffles
- Sandwiched in cakes
Related recipes
Looking for more preserving recipes? Try these!
Full Recipe
Chia Blackberry Jam Recipe - Low Sugar
Blackberries and chia seeds are the base of this low sugar blackberry jam recipe. Blackberries bring the flavour and the chia seeds thicken it up.
Ingredients
- 450g fresh or frozen blackberries , (or berries of your choice)
- 1 tablespoon lemon juice
- 1 pinch salt
- 2-3 tablespoon sugar or sweetener of your choice , (use more or less as needed)
- 1 ½ tablespoon chia seeds
Instructions
- In a saucepan over medium heat add the blackberries and the lemon juice. Stir it together continuously as the berries start to release their liquids.
- Once the berries have broken down, let it come to a simmer and let it simmer for 15-20 minutes stirring regularly as the liquid reduces. Frozen berries usually release more liquid than fresh and may take a little longer. Add a pinch of salt and sweetener of your choice and stir it through.
- While the jam is simmering, clean and sterilize the jars you are using by giving them a soapy wash and rinsing well. Place the washed jars upright on a baking tray and put them into a low oven at 120C/248F for about 15 minutes or until jars are completely dry.
- Once most of the excess liquid has been reduced, take the pan off the heat. Stir through chia seeds, mixing them in well.
- Carefully pour the hot jam into the hot jars, clean the jar rims and seal the jars. Let them cool right down to room temperature.
- Store it in the fridge for up to a week or the freezer for up to three months. Alternatively, the jam can be preserved in a hot water bath in which case it can store unopened for up to 6 months. Once opened, store in the fridge and use within a week. (See the above post for preserving via a hot water bath.)
Nutrition Information:
Yield: 10 Serving Size: 1 gramsAmount Per Serving: Calories: 41Total Fat: 1gSaturated Fat: 1gTrans Fat: 1gUnsaturated Fat: 0gSodium: 5mgCarbohydrates: 9gFiber: 3gSugar: 6gProtein: 1g
Selena Wilson, Janet Heubach says
Hi Elien, how do I modify this recipe if I use raspberries? Thanks.
Selena
Elien says
Hey you can make it exactly the same 🙂