Marionberries are almost exclusively grown in the Pacific Northwest, so I feel very lucky that I live 30 minutes from a beautiful Marionberry farm! I took my toddler to pick berries for the first time with the intention of using my grandma’s delicious raspberry freezer jam recipe to make Marionberry Jam! I have never made homemade Marionberry jam before, but I love the flavor Marionberries give. Since my Grandma’s jam recipe is so versatile, I had to try it!

My grandmother’s freezer jam recipe has been a treasured family tradition for generations. I grew up making it with my mom every summer, just as she did with her mom. It was always a highlight of the season, and we were so lucky to have homemade jam filling our freezer. I’ve never bought jam from a store! My toddler (and I!) love it. One of the best things about it is how versatile it is; I’ve used this recipe for strawberries, blackberries, raspberries, and now marionberries! I can’t wait for you to try my grandma’s easy marionberry freezer jam!

Ingredients you will need

Marionberries
Pectin
Lemon Juice
Karo Syrup
Sugar

Recipe Tips & Tricks

Perfectly Pureed Berries: For a deliciously smooth jam, thoroughly wash your Marionberries then add them to a blender and mix until pureed.

Smooth Jam, No Lumps: The key to avoiding lumps is to stir the pectin in slowly. If you’re making this with a helper (like your mom!), have one person stir constantly while the other slowly pours in the pectin.

Heating the Jam: When heating the jam mixture on the stove, you only need to warm it to room temperature. My mom taught me a great trick: dip your pinky finger into the pot. If the jam feels cold, keep heating. Once it reaches the right temperature, you’ll barely feel it when you dip your finger in. As soon as you reach that point, remove it immediately from the heat.

Freezing in Glass Jars: If you’re using glass jars, do NOT fill them to the very top and do NOT screw the lids on tightly before freezing. I literally just rest the lid on top without twisting it. This prevents the jars from cracking as the jam freezes and expands. Once the jam is completely frozen (after about 24 hours in the freezer), then tighten the lids.

Baking Tools I used

What is Pectin?

Pectin is a natural gelling agent found in the cell walls of fruits, especially citrus. It’s commercially available as a white powder. When added to jam with sugar, pectin causes the mixture to thicken, making it a perfect, natural additive for jams.

You can typically find pectin in the baking aisle or near canning supplies at most grocery stores (I usually get mine at Kroger or Walmart). You can buy it online here!

How much Jam will I make?

This recipe makes one “batch” or “round” of jam. When my mom and I make jam, we usually prepare multiple rounds in one afternoon. For example, if I make four rounds of this recipe, I get about 12 of the 16-ounce Mason jars filled with jam. So, one round of this recipe yields roughly 3 Mason jars of jam.

For reference, four rounds of this recipe, which made 12 jars of jam, required about half a flat of marionberries.

How to make Easy Marionberry Freezer Jam:

Prepare your jars or containers: Wash them thoroughly and set them out.
Wash the marionberries thoroughly.
Puree the marionberries Add the washed berries to a blender and mix until smooth.
Combine with lemon juice: Pour the pureed berries into a bowl, add the lemon juice, and stir until well combined.
Slowly stir in pectin: Gradually add the pectin to the berry mixture, stirring constantly to ensure there are no clumps. Once all the pectin is mixed in, let the berry mixture sit for 30 minutes.
Heat the mixture: After 30 minutes, transfer the berry mixture to a medium saucepan. Add the sugar and Karo syrup.
Heat until no longer cold: Continuously stir the mixture while heating it until it’s no longer cold to the touch (use the pinky finger trick mentioned above!). Immediately remove it from the heat.
Pour into jars and cool: Carefully pour the jam into your prepared jars. Let them cool completely at room temperature before placing them in the freezer.

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