Blackberry Jam (Homemade Canning Recipe)

Instructions:

1. Prepare a boiling water bath canner and keep 8 half-pint jars hot until ready to fill.
2. Wash and sort the blackberries, removing any stems, leaves, or damaged berries.
3. Lightly crush the berries in a large stainless steel pot.
4. Stir in the bottled lemon juice and bring the berry mixture to a boil over medium-high heat.
5. Add the granulated sugar all at once, stirring constantly until it has completely dissolved.
6. Bring the mixture to a full rolling boil that cannot be stirred down.
7. Continue boiling hard, stirring frequently, until the jam reaches the gel stage, about 10 to 15 minutes. Test for doneness using your preferred gel test if desired.
8. Remove the pot from the heat and skim off any foam for a clearer finished jam.
9. Ladle the hot jam into the prepared hot jars, leaving ¼-inch headspace.
10. Remove any trapped air bubbles using a non-metallic utensil. Adjust the headspace if necessary, then wipe the jar rims clean.
11. Apply the lids and screw bands until fingertip tight.
12. Process the jars in a boiling water bath:
    • Half-pint jars: 10 minutes
    • Pint jars: 15 minutes
    • Adjust processing times according to your altitude if necessary.
13. Carefully remove the jars and allow them to cool undisturbed for 12 to 24 hours. Verify that each lid has sealed properly before storing in a cool, dark place.

Variations

• Press the crushed berries through a fine-mesh sieve or food mill before cooking for a smooth, seedless jam.
• Add 1 teaspoon of vanilla extract after opening a jar for a rich dessert-style flavor.
• Stir in a pinch of ground cinnamon for a subtle warm spice note.
• Mix blackberries with raspberries or blueberries for a delicious mixed berry jam, using a tested recipe.
• Use the finished jam as a glaze for roasted pork, grilled chicken, or baked brie.

Tips

• Use fully ripe, firm blackberries for the best flavor, color, and natural pectin.
• Cook the jam in a wide, heavy-bottomed pot to encourage faster evaporation and even cooking.
• Stir frequently during the final boil to prevent scorching.
• A chilled plate or spoon test is a simple way to check whether the jam has reached the proper gel stage.
• Leave the recommended ¼-inch headspace to help ensure a proper seal during processing.
• Label each jar with the canning date and store in a cool, dark pantry for the best quality.
• Once opened, refrigerate the jam and enjoy it within 3 to 4 weeks.
• For the freshest flavor, allow the jam to rest for 1 to 2 weeks before opening so the texture and flavor can fully develop.