This blackberry jam is rich, tangy, and perfectly sweet without being overloaded with sugar. If you’ve been searching for a low sugar jam recipe that actually tastes amazing, this one’s for you. With just a handful of ingredients, it’s a simple and satisfying way to capture the flavor of summer. Learn how to preserve blackberries in a way that’s fresh, vibrant, and spreadable—this recipe will have you reaching for toast, biscuits, and more.
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When my small row of blackberry bushes had an epic bumper harvest, I found myself left with bags and bags of homegrown berries in the freezer. While there are so many recipes I love to make with blackberries (see the end of this post for a few ideas), blackberry jam is my favorite.
This recipe comes together quickly with just a few ingredients. The better quality the berries, the better the jam. And what better quality can you get then picking them yourself from your backyard? Read on for all the recipe details (including a full video below), plus some tips on how you can grow your own blackberry patch.
Watch the video below to see this recipe in action:
The Secret to Making Low-Sugar Jam
The best fresh fruit recipes are those that actually end up tasting like the fruit itself. This was the goal of my low-sugar blackberry jam recipe. I love the sweet-tart, juicy flavor of fresh picked blackberries right off the bush. What’s the point of making jam if it covers up the flavor of the fruit with a bunch of sugar?
Low-sugar pectin is my favorite way to make jams that actually taste like fruit. Pectin is a naturally occurring (protein? Enzyme?) that acts as a thickener or jelling agent. You can make blackberry jam without pectin, as the fruit already contains some, but you would have to add more sugar and a longer cooking time in order to thicken it.
The low-sugar or no-sugar pectin allows you to just add enough sugar to balance the flavor, without having to cook down the berries for a long time. Quicker cooking time means the bright freshness of the blackberries remains, but the jam is the perfect spreadable texture.
Grow Your Own Blackberries
Blackberries are a fantastic crop to grow in a home garden if your goal is abundance and food security. A healthy blackberry plant can provide up to about 10 pounds of berries per year. Plus, once the plants are established, they take little active care.
Blackberry plants thrive in warm climates, but there are many varieties that can tolerate colder temperatures. Wild blackberries grow as trailing vines, which can quickly take over a large area. But there are also cultivated varieties that grow erect, and even many thornless options.
Learn more: The Best-Tasting Thornless Blackberries (9 Top Picks) and The Best Blackberry Varieties for Cold Climates
All you need to grow your own blackberries is a lot of sun – at least 6 to 8 hours of direct sunlight – and some space. Sun is the key to having vigorous, productive plants that produce large and sweet berries. Check out the articles below for more information on how to grow blackberries.
- Why Are My Blackberries Sour? Tips to Grow Sweeter Berries
- The Ultimate Guide to Pruning Blackberries (+ Video)
- Blackberry Fertilizing: What to Use to Grow the Best Berries
Blackberry Jam Recipe Instructions (with Photos)
Measure out all of the ingredients ahead of time. Scoop out about ¼ cup of the sugar and mix it with 3 tablespoons of pectin – this will help keep the pectin from clumping when added to the fruit.
If you are canning the jam for long-term storage, wash and sanitize the jars and lids. Keep them hot until it’s time to fill them.
Add the clean, fresh or frozen berries into a large pot and slowly bring to a simmer over medium heat. I suggest using a potato masher to break up the berries as they cook and release their juice.
Once the fruit is heated and simmering, you’ll want to remove the seeds. Blackberry seeds are very noticeable and crunchy in jam. In my opinion this is a must-do-step. Either use a spoon and a metal sieve to press the blackberry pulp through until only the seeds remain, or use a food mill (which is what I prefer) to quickly de-seed the fruit.
Pour the seedless puree back into the pot and return to a simmer. Add in the pectin/sugar mixture and lemon juice and mix until well combined. Bring this to a full rolling boil and continue boiling for 1 minute.
Then add the rest of the sugar, stir, and boil again for 1 minute.
At this point, test the jam for flavor and texture. If the jam needs to be sweeter (blackberries can range widely in sweetness), add more sugar ¼ cup at a time, boiling for a minute between additions.
To test for thickness, place a couple of spoons in the freezer. Scoop out some jam and see how thick it is on the spoon as it cools. If it’s too runny, add in more pectin 1 tablespoon at a time, testing for jell between each addition. I rarely have to use more than 4 tablespoons total, but it depends on the brand of pectin and the berries themselves, as well as your preference.
Carefully ladle the finished jam into the clean, sterile jars (or other containers if you are not canning). I prefer using this batter dispenser - it's so fast and minimizes mess when transferring the jam to jars. Leave ½ inch of headspace, and wipe the rims of the jars clean with a damp paper towel. Top with warmed lids and hand-tightened rings.
Process the jam for 5 minutes in boiling water that is at least 1 inch over the tops of the jars. If you live at greater than 1000 feet elevation, add 1 minute of processing time for every 1000 feet. Remove the jars and allow them to cool at room temperature over the next 24 hours.
This blackberry jam is amazing just on plain toast. But you can also use it as a filling for turnovers, swirled into muffins, or warmed up as a sauce for cheesecake. Here are a few of the blackberry recipes I keep coming back to with my homegrown berries:
- Salted Honey and Blackberry No-Churn Ice Cream
- Blackberry Gochujang Barbecue Sauce
- Blackberry Blood Orange Marmalade
Simple Low-Sugar Blackberry Jam
Equipment
- Large pot
- Metal strainer or food mill
- Ladle and jar funnel
- Jars and lids for canning optional
- Water bath canner or large stock pot optional
Ingredients
- 12 cups fresh or frozen blackberries
- 2 - 2 ½ cups granulated sugar
- ¼ cup bottled lemon juice
- 3 - 4 tablespoons low sugar or no sugar needed pectin
Instructions
- Set up the canning equipment (if using). Clean and sterilize jars and lids. Keep the jars and lids hot while cooking the jam. Place two spoons in the freezer to use for checking the jam texture.
- Pre-measure the ingredients. Combine the pectin with ¼ cup of the measured sugar to help prevent it from clumping, and set aside.
- Prepare the fruit. Heat the berries in a large pot over medium heat until simmering, and cook for a minute or two (just long enough to break down the berries). Use a potato masher to break up the fruit and release the juice.
- Remove the seeds from the cooked blackberries by pouring through a metal sieve and pressing the pulp through with a spoon. An easier way to de-seed the fruit is with a food mill. Keep as much of the pulp as possible while removing the seeds, otherwise you are making jelly (out of only the blackberry juice) rather than jam (juice and pulp).
- Return the now seedless puree to the pot and add in the pectin/sugar mixture and lemon juice. Bring to a full rolling boil, stirring occasionally, and boil for 1 minute. Then add the remaining sugar, stir, and boil again for 1 minute.
- Check for jell and sweetness. Scoop out a little jam with a cold spoon and allow it to cool. Look for the jam to be thick and viscous, but still spreadable. You may notice little wrinkles on the surface of the jam as it cools. If it seems too runny, add in another tablespoon of pectin and boil for 1 minute. Check for jell again; repeat until the desired texture is reached.
- Taste the jam for sweetness. If it needs to be sweeter, add in sugar ¼ cup at a time, boiling between each addition. Blackberries can vary widely in sweetness, so be sure to taste as you go to get the right sweet-tart balance.
- To can the jam, ladle in to hot jars leaving ½ inch of head space. Wipe the jar rims clean with a damp paper towel. Top with warmed lids, and hand-tighten the jar rings. Place them in hot (about 200dF) water (you can use the same sanitizing water) that is at least 1 inch over the tops of the jars, and bring to a full boil. Boil for 5 minutes to process the jam (add 1 minute of processing time for every 1000 feet of elevation). Carefully remove the jars and set them aside on a towel to cool at room temperature over the next 24 hours. Store sealed jars in a cool, dry place for up to 6 months – 1 year. Store any unsealed jars in the refrigerator and use within 2 weeks.
Video
TIPS
- For freezer jam, pour into freezer-safe containers and freeze for up to 6 months.
- This same recipe can be used for other combinations of berries, such as blueberries or raspberries. I especially love the blueberry-blackberry combination.
