Menu Idea

Gather the ingredients, and have ready 4 half-pint glass canning jars with bands and new lids.

Line the bottom of a large, deep pot with a folded clean kitchen towel or canning rack, and place preserving jars in the pot. Add water to cover jars by 1 inch (filling jars with water to prevent flotation).

Bring to a boil over high, and boil for 10 minutes. Turn off heat. Using a jar lifter or tongs, remove jars from the pot, letting water drain back into the pot, and place on a dry towel. Reserve the pot of hot water.

While jars boil, place 3 cups blackberry puree into a medium nonreactive pot and stir in 3 tablespoons pectin and 1 1/2 tablespoons bottled lemon juice. Bring to a rolling boil over medium-high, stirring occasionally.

Add 2 1/2 cups (524 grams) granulated sugar and return to a rolling boil over medium-high, stirring occasionally. Boil 1 minute, stirring constantly. Remove from heat.

Working with 1 jar at a time and using a canning funnel, ladle jam into hot jars, leaving 1/4 inch of headspace (there might be a small amount of jam leftover). Wipe jar rims. Top with lid, and screw on jar band until fingertip tight.

Using a jar lifter, carefully lower filled jars into hot water, and make sure jars are covered by 1 inch of water (add hot water if needed). Cover and bring to a boil over high. Boil for 10 minutes. Uncover and turn off heat. Let stand 5 minutes.

Place a kitchen towel on a work surface. Using a jar lifter, carefully remove jars from pot and place on towel. Let stand, undisturbed, at least 12 hours or up to 24 hours. Check seals (lids should be curved inward), and label.