Description

This homemade blackberry jam recipe offers a delicious way to preserve the fresh, sweet taste of blackberries with a classic balance of sugar and lemon juice. Using fruit pectin ensures a perfect gel consistency without the wait, making it simple to create vibrant, spreadable jam ideal for toast, desserts, or gifts. The recipe includes optional steps for smoother jam texture and detailed instructions for both freezer and canning preservation methods.

Ingredients

Scale

Fruit Base

2.5 quarts fresh or frozen blackberries (about 8 cups)
2 tablespoons lemon juice

Sweetener & Thickener

7 cups granulated sugar
1 packet liquid fruit pectin (Sure-Jell or Certo)

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Instructions

Prepare for Canning (optional): If you plan to can the jam, begin by preparing a boiling water bath and sterilizing your jars and lids to ensure a safe preservation process.
Rinse Blackberries: Rinse the blackberries thoroughly just before use to remove any debris or impurities.
Mash and Simmer Fruit: Place the berries in a large saucepan with lemon juice and mash them using a potato masher. Simmer over medium heat for a few minutes until the fruit breaks down and releases its juices.
Strain Seeds (optional): For a smoother jam texture, pass the mixture through a food mill or fine mesh strainer to remove most seeds. This step is optional but recommended.
Measure Juice for Jam Base: Measure out 4 cups of the blackberry juice into a large, heavy-bottomed pot. Stir in 2–3 spoonfuls of reserved seeds to retain a classic jam texture that balances smoothness and seediness.
Add Sugar: Add the granulated sugar to the juice and stir well to combine.
Dissolve Sugar: Cook the mixture over medium-low heat, stirring occasionally, until the sugar is fully dissolved.
Boil the Mixture: Increase heat to medium-high and bring the mixture to a full rolling boil, stirring constantly to prevent burning.
Add Pectin and Boil: Stir in the liquid fruit pectin and continue stirring as the jam returns to a full boil. Boil for exactly 1 minute, then remove from heat.
Jar the Jam: Carefully pour the hot jam into your prepared jars and seal them with lids.
Freezer Storage Method: Allow the jam to cool at room temperature for 24 hours. Store it in the refrigerator for up to 1 month or freeze for up to 1 year for longer preservation.
Canning Storage Method: Process the sealed jars in a boiling water bath for 10 minutes (adjust for altitude if necessary). Let jars rest undisturbed for 24 hours, check the seals, and store in a cool, dry place for up to 1 year.

Notes

Using fresh or frozen blackberries will work; frozen may require slightly longer cooking time.
The optional straining step improves jam texture by removing most seeds but will reduce seediness.
Stir constantly during boiling to avoid scorching the jam.
If high altitude, increase boiling water bath time to ensure proper sealing during canning.
Leftover jam can be refrigerated up to 1 month or frozen up to 1 year – freeze in airtight containers.
Always sterilize jars and lids for safety if using the canning method.