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Blackberry jam – Caroline’s Cooking

    jar of blackberry jam with some on bread to one side and spoonful on small plate behind

    Blackberry jam is brightly colored and bursting with fruity flavor. This one is made in a small batch with lower sugar and comes together quickly for a delicious spread, perfect for toast and more.

    jar of blackberry jam with some on bread to one side and spoonful on small plate behind

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    One of my main memories of summers as a child (apart from trips away) is picking berries. And, of course, eating them!

    We would pick a lot of them and many different kinds. We went to one fruit farm in particular where we’d pick strawberries, raspberries, currants if they were around and maybe some lesser-known berries like tayberries. Blackberries, or brambles as we called them, we’d forage in various locations in the area.

    Naturally, I’d eat a bit as we picked, particularly the foraged blackberries, then we’d keep some in the fridge to enjoy fresh. The rest we’d either freeze for later use or make into jams.

    jar of blackberry jam with blackberries to side

    A growing jam making habit

    Given I was always brought up with jams, I’m not sure why it took my that bit longer to get back into making them. But given my little taste testers are big fans, I’ve started making them much more often.

    Homemade is nearly always better flavor-wise, and I prefer to make most lower sugar as well. Strawberry raspberry jam is probably one we make the most, but we enjoy many others too. Blackberry jam is one I remember helping to make as a child and it has such a wonderful flavor to it. I’m glad to say, everyone else in our house agrees.

    blackberries, sugar and lemon juice in pan

    Do you need to add pectin?

    Blackberries are relatively high in natural pectin so you don’t need to add any, in my opinion. Also, I like to add a little lemon which helps bring out the flavor and helps with setting as well.

    Making lower sugar jams

    As I mentioned, this is a lower sugar jam, which is my general preference. I find many commercial jams way too sweet and you taste more sugar than fruit. Many ‘traditional’ jams use around equal weights of fruit to sugar, while lower sugar jams tend to be more in the 1 part sugar to 3 or 4 parts fruit.

    starting to cook jam - blackberries changing color

    The downsides to lower sugar jams are that it tends to take longer to cook to get it to set (or else is a bit runnier, and doesn’t keep as long), and the yield tends to be less. That’s both as you have less ingredients overall and because you are cooking for a little longer, the liquid reduces. But I think the trade off is well worth it.

    Ways to help speed things up are using a relatively wide pan for the quantity of fruit you use and making smaller batches. More surface area allows the jam to heat more evenly and thicken quicker.

    jam bubbling in pan showing chunks of berries

    The lower sugar means you tend to have more chunks of fruit, so it’s worth helping them along to break up as it cooks. But those chunks taste so good!

    You may find that the jam foams up as it is cooking. If it does, them just keep stirring it down and you can reduce the heat a little as well, if needed to have more of a simmer rather than roaring boil. If there is still foam on top once ready, skim this off before putting the jam in a jar.

    stirring jam with spatula

    How do you know when it’s ready?

    As it cooks, the jam will fruit will break down and the mixture start to thicken. The quick guide to know that it is ready is it will take longer to fill in behind a spatula as you stir through the mixture. To be more sure, you can test some by chilling a plate ahead of time and putting a small spoonful of the jam on the plate. After a short rest to cool, push the jam and it should wrinkle on the surface.

    The jam is then ready to transfer to a sterile jam. It’s worth referring to the USDA Home Canning guide for tips on safe preservation, if you are less sure.

    This makes a relatively small batch so it’s easy to get through quickly. It’s great on toast etc, but we also enjoy it to top some pate crostini. It would be great used to fill cakes as well.


    This lower sugar blackberry jam has only three ingredients and being small batch, cooks pretty quickly. The result is a wonderfully tasty, bright and fruity jam. It’s perfectly sweet without being overly so. Just what your toast needs.

    jar of blackberry jam with some on bread to one side and blackberries in front on other side

    Try these other tasty jams and spreads:

    jar of blackberry jam from overhead with some on bread to side

    Print Recipe

    blackberry jam

    This bright and fruity jam is low in sugar but full of wonderful flavor. Quick, easy and delicious.

    Prep Time5 mins

    Cook Time20 mins

    Total Time25 mins

    Race: Condiment

    Kitchen: British

    Services: 10 (approx – makes around ½ cup)

    calories: 50calories

    Author: Caroline’s Cooking



    • 9 oz blackberries 250g (2 small boxes)
    • ½ cup sugar 100g
    • 1 tablespoon lemon juice


    • Put the berries, sugar and lemon juice in a small-medium saucepan and put on a medium heat. Stir as it heats to dissolve the sugar. Break up the berries with a spatula/spoon a little as they soften. As it cooks, prepare your jar/jars – either warm in a low over a few minutes or submerge in boiling water to sterilize. Take care using thongs/gloves to handle as you remove.

    • Bring the jam to a simmer, reduce the heat a little and simmer for approximately 15 minutes (or longer, as needed), stirring occasionally. The blackberries will initially become brighter then the mixture will become darker and more even in color. It will also start to thicken – when you stir a spoon/spatula through, it will take a bit longer to close in behind.

    • Remove the pan from the heat, allow to cool a minute or two then skim off any foam. Transfer to your prepared clean jar(s) and put lid on while still hot. Leave to cool.


    calories: 50calories | Carbohydrates: 13g | protein: 1g | Fat: 1g | Saturated Fat: 1g | Sodium: 1mg | Potassium: 42mg | fiber: 1g | Sugar: 11g | Vitamin A: 54UI | Vitamin C: 6mg | Calcium: 7mg | Iron: 1mg

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    Blackberry jam is brightly colored and bursting with fruity flavor.  This one is made in a small batch with lower sugar and comes together quickly for a delicious spread, perfect for toast and more.  #jam #preserving #blackberry