Ingredients:

  • 4 cups fresh blackberries (600 grams)
  • 2 cups granulated sugar (400 grams)
  • 1/4 cup fresh lemon juice (60 ml)
  • 1/2 teaspoon ground cinnamon (optional)
  • 4 small glass jars with lids

Instructions:

  1. Sterilize the jars by boiling them and lids in water for 10 minutes; keep warm.
  2. Rinse blackberries under cold water and remove any stems or leaves. Gently mash the blackberries in the pot for a slightly chunky texture.
  3. Add sugar, lemon juice, and optional cinnamon to the pot with the blackberries.
  4. Stir to combine and bring the mixture to a boil over medium heat. Reduce to a simmer, stirring frequently, for about 30 minutes or until the mixture thickens.
  5. Use a thermometer to check that the rolling boil reaches 220°F (104°C) for the set.
  6. To test for doneness, place a spoonful of jam on a cold plate; it should hold its shape when pushed with your finger.
  7. Using a ladle, fill the sterilized jars with the hot jam, leaving about 1/4 inch of space at the top. Wipe the rims with a clean dishcloth.
  8. Place the lids on the jars and screw on the bands until fingertip-tight.