Ingredients:

  • 6 cups (900 g) Fresh Black Raspberries, gently washed and dried
  • 4 cups (900 g) Granulated White Sugar
  • 4 Tbsp (60 ml) Fresh Lemon Juice
  • 1 tsp (5 g) Unsalted Butter (optional, to reduce foaming)
  • 6-7 Half-Pint Jars with two-part lids

Instructions:

  1. Sterilise the Jars: Wash jars and lids thoroughly. Sterilise the glass jars using the oven method (250°F/120°C for 15 minutes) or by boiling in a large pot for 10 minutes. Keep the jars hot until ready to fill.
  2. Macerate (Optional but Recommended): In the large pot, gently combine the black raspberries and the sugar. Cover and leave to stand for 1–2 hours (or overnight in the refrigerator). This draws out the fruit’s liquid, speeding up the cooking time and helping the flavour develop.
  3. Prepare the Set Test: Place a small ceramic plate into the freezer.
  4. Dissolve the Sugar: Place the pot over medium heat. Stir constantly and gently until all the sugar is completely dissolved. The mixture should look clear, with no granules remaining (listen for the cessation of the 'grating' sound).
  5. Achieve a Rapid Boil: Add the lemon juice. Increase the heat to high and bring the mixture to a rapid, rolling boil—a boil that cannot be stirred down.
  6. Start Timing and Thermometer: Insert the candy thermometer. Boil vigorously, stirring only occasionally to prevent sticking. Add the butter now (if using) to help reduce the aggressive foam build-up.
  7. Monitor Temperature: Continue boiling until the mixture reaches 105°C (221°F). This is the common set point for high-sugar jams.
  8. Test for the Set (Wrinkle Test): Once the temperature is reached, remove the pot from the heat. Spoon a small amount of jam onto the frozen ceramic plate. Return the plate to the freezer for 30 seconds. Push the jam with your finger; if it wrinkles, the set is spot on. If it remains liquid, return the pot to the heat and boil for another 2–3 minutes before re-testing.
  9. Skim the Foam: Once the set is achieved, remove any foam (scum) from the surface using a metal spoon or ladle. Discard the foam.
  10. Fill the Jars: Carefully ladle the hot jam into the hot, sterilised jars, using a funnel. Leave about 1/2 inch (1.25 cm) headspace.
  11. Seal and Process: Wipe the rims clean. Place the lids on finger-tight. Process the jars in a boiling water bath for 10 minutes (for long-term shelf stability).
  12. Cool and Check Seal: Remove the jars and let them cool on a wire rack undisturbed. The lids should seal (you'll hear a 'pop'). Label and store in a cool, dark cupboard.