1-First Step: Prepare Your Workspace and Ingredients Thoroughly clean and sterilize large jars and a pot (at least 8 quarts) for canning. Gently crush 5 cups of fresh or thawed frozen blackberries with a potato masher, being careful not to puree the fruit completely to maintain texture.

2-Second Step: Combine Fruit and Pectin Place the crushed blackberries in the pot. Slowly stir in the dry pectin while stirring constantly to disperse evenly and prevent clumping.

3-Third Step: Heat and Boil the Mixture Heat the blackberry and pectin mixture over high heat, stirring continuously until it comes to a full rolling boil that cannot be stirred down. This step is crucial for activating the pectin and achieving the right jam consistency.

4-Fourth Step: Add Sugar and Cook Further Add all 7 cups of sugar at once, stirring well to dissolve. Bring the mixture back to a full hard boil and maintain for exactly 1 minute, stirring constantly. Avoid boiling longer than specified to prevent texture breakdown.

5-Fifth Step: Remove Foam and Fill Jars Remove from heat and skim off any foam on the surface to improve clarity and texture of the finished jam. Carefully ladle hot jam into hot, sterilized 8-ounce jars, leaving about 1/4 inch headspace at the top.

6-Sixth Step: Seal and Process! Wipe jar rims clean, place lids on top, and screw on rings fingertip tight. Process jars in a boiling water bath where water covers jars by at least 1 inch for 10 minutes (adjust time for altitude if necessary).

7-Final Step: Cool, Seal, and Store Remove jars from the boiling water bath and set upright on a towel to cool completely for 12 to 24 hours. After cooling, check seals – lids should not flex up and down. Store sealed jars in a cool, dark place or refrigerate once opened. Use within weeks for the best flavor, or freeze portions for longer storage.