Ingredients:

  • 4 cups (600g) fresh blackberries
  • 2 cups (400g) granulated white sugar
  • 2 tbsp (30ml) freshly squeezed lemon juice

Instructions:

  1. Combine the blackberries and sugar in a wide-bottomed heavy pot. Use a potato masher to crush about half of the berries to release juices while keeping some whole. Let the mixture sit for 10 minutes until syrupy.
  2. Stir in the lemon juice. Place the pot over medium-high heat and bring the mixture to a full, rolling boil, stirring frequently to prevent the sugar from caramelizing on the bottom.
  3. Using a digital candy thermometer, continue boiling until the jam reaches 220°F (104°C). Verify with the plate test: a dollop of jam on a frozen plate should wrinkle when pushed with a finger.
  4. Remove from heat immediately. Ladle the hot jam into sterilized jars, leaving 1/4 inch of headspace. Wipe rims clean, apply lids, and tighten. For long-term storage, process in a water bath for 10 minutes.