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Blackberry Jam Recipe

Blackberry jam is an irresistibly thick, sweet, and fruity spread that makes breakfast extra special.

You can spread it on bread, stuff it in French toast, use it as a pie filling, or add it to your oatmeal. Either way, it just makes every meal a little bit sweeter.

Blackberry Jam
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But there’s 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! 

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

Homemade Blackberry Jam

There are many things I love about homemade blackberry jam. I love that it’s quick and easy to make. I love that it only requires six simple ingredients.

And most of all, I love that it tastes better, fresher, sweeter, and fruitier than anything you can get at the store.

I know we’re all busy all the time. But even the busiest of us can spare 30 minutes to make something that tastes this good.


As I mentioned, this recipe requires only six ingredients:

  • Blackberries. Blackberries are the star of the show with this recipe, of course. Fresh ones are best, but you can use frozen ones in a pinch. Jump to the “Can You Make Jam with Frozen Blackberries” section below for more info.
  • Sugar. Granulated sugar is fine. It sweetens the berries and cuts through some of their tartness.
  • Cornstarch. You’ll need this to help thicken the jam.
  • Ground cinnamon and allspice. Technically, you can make blackberry jam without these spices. However, they give it a rich, robust flavor that’s impossible not to love.
  • Lemon juice. Just a little fresh lemon juice helps enhance all the other flavors.

How to Make Blackberry Jam

1. Mash and sweeten the berries. Pour the blackberries into a saucepan and mash them with a potato masher. This process can be messy, so you may want an apron.

Once they are good and mashed, stir the sugar into the berries.

2. Add the cornstarch. Remove a tablespoon of blackberry juice from the mixture. Transfer it to a small bowl and add the cornstarch to it. Mix well.

Then, pour this mixture back into the original mashed and sweetened berries.

3. Boil. Bring the sweetened berries to a boil, stirring constantly. Boil for about 15 minutes or until the mixture thickens.

4. Add the spices. Once the mixture thickens, stir in the allspice and cinnamon.

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5. Cool. Remove the pan from the stove and let the jam cool. Then, transfer it to a bowl and cover it with aluminum foil.

Place the bowl in the fridge to chill.

6. Finish the jam. Once the jam is chilled, remove it from the fridge and stir in the lemon juice. Mix well. You can then serve it immediately or store it in an airtight container for later use.

Tips & Tricks for Making the Best Blackberry Jam

Keep the following tips in mind:

  • Watch the boiling berries closely. 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. 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.
  • Use only fully ripe blackberries. Ripe berries have the highest amount of pectin, which is what gives jam that gel-like consistency.
  • Clean the berries thoroughly. 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, leaving a metallic taste in the mouth.
  • Use a candy thermometer. You want the jam to reach 220 degrees Fahrenheit, as that is the temperature at which sugar turns into gel and bonds with pectin. A candy thermometer is the best way to ensure the jam is at the right temperature.
  • Substitute honey for sugar. If you make this swap, increase the amount of cornstarch to 2 1/2 tablespoons to help thicken the jam.
  • Mash the blackberries one cup at a time. Don’t try to mash too many at once, and don’t puree them. Jam has to have fruit bits in it. If you don’t have a potato masher, use a wire whisk instead.
  • Make it seedless. Simply strain the mashed blackberries through a cheesecloth or a fine-mesh sieve. 
  • Ensure the sugar dissolves. Be sure the sugar dissolves in the blackberry mixture before you bring it to a boil. Otherwise, it will give the jam a grainy texture.
  • Don’t 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. The key is to partially thaw the berries before using them.

You can then follow the recipe as instructed.

The upside to using frozen blackberries? You can make tasty blackberry jam all year long!

Blackberry Jam Recipe



Prep time


Cooking time






  • 4 cups blackberries

  • 1 cup white sugar

  • 2 tablespoons cornstarch

  • 1/4 teaspoon ground cinnamon

  • 1/4 teaspoon ground allspice

  • 1/2 teaspoon 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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author avatar
Kim - InsanelyGood
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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