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Blackberry Jam Recipe

Blackberry jam is an irresistibly thick, sweet, and fruity spread that makes breakfast extra special. Whether you spread it on bread, stuff it in French toast, use it as a pie filling, or add it to your oatmeal, it just makes every meal a little bit sweeter.

No need to buy jam from the store when you can make your very own homemade blackberry jam. There’s something special about making it yourself. And the best part is, it’s incredibly easy to make! 

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All you need is fresh (or frozen) blackberries, sugar, and a splash of lemon juice.

Blackberry Jam

Tips & Tricks for Making the Best Blackberry Jam

  • Take note that blackberry jam foams while cooking, so you’ll need to watch it closely and stir down the foam when it rises. You can also add 1/4 teaspoon of butter to prevent it from foaming too much.
  • Be patient while cooking your jam. The result should be a gel-like substance. If it has not gelled yet, that means it’s not cooked long enough. Place the heat on low while mixing towards the end to prevent the jam from burning.
  • When picking blackberries for jam, make sure they are at their ripest stage. Ripe berries have the highest amount of pectin, which is what gives jam that gel-like consistency.
  • Be sure to rinse and clean the blackberries well before you mash them. 
  • Use a stainless steel pan when making jam. Other metals will react with the blackberries and will leave a metallic taste in the mouth.
  • Use a candy thermometer to make sure you are on the right track. You want the jam to reach 220 degrees Fahrenheit, as that is the temperature at which sugar turns into gel and bonds with pectin.
  • You can also use honey instead of sugar, but increase the amount of cornstarch to 2 1/2 tablespoons to help thicken the jam.
  • For best results, mash the blackberries 1 cup at a time, and do not puree them. Jam has to have fruit bits in them. If you do not have a potato masher, use a wire whisk instead.
  • If you want seedless jam, strain the mashed blackberries through a cheesecloth or a fine-mesh sieve. 
  • Be sure the sugar dissolves in the blackberry mixture before you bring it to a boil, otherwise, the sugar will give the jam a grainy texture.
  • Do not make large batches all at one time. Large quantities of sugar and blackberries will take a longer period to set, which will cause the blackberries to dissolve into the jam. I like to make small batches. Fresh jam is always best!

Can You Make Jam with Frozen Blackberries?

While fresh is best, you can also use frozen blackberries to make jam. Plus, this way you can make jam year round! The key is to thaw the berries partially. You can then follow the recipe as instructed.

How to Make Blackberry Jam

Blackberry Jam Recipe



Prep time


Cooking time






  • 4 cups 4 blackberries

  • 1 cup 1 white sugar

  • 2 tablespoons 2 cornstarch

  • 1/4 teaspoon 1/4 ground cinnamon

  • 1/4 teaspoon 1/4 ground allspice

  • 1/2 teaspoon 1/2 lemon juice


  • Place blackberries in a saucepan and mash them with a potato masher. Be careful – the blackberries will squirt out juices as you do this, so I recommend that you wear an apron.
  • Stir sugar into the blackberry mash and mix until juices form.
  • Pour a tablespoon of the juice into a separate container. Pour in the cornstarch and mix until combined. Place cornstarch mixture into the blackberry mixture.
  • Bring berries to a boil. Stir constantly until the jam has thickened. This will take about 15 minutes. Stir in cinnamon and allspice. Remove from heat and allow to cool. Place the jam into a bowl, cover, and refrigerate until chilled. Add in lemon juice and mix well.
  • Enjoy!

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Hey there! I'm Kim. I love running, cooking, and curling up with a good book! I share recipes for people who LOVE good food, but want to keep things simple :)

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