Ingredients:

  • 2 cups (300g) fresh rhubarb, finely diced into ¼-inch pieces
  • 4 cups (600g) fresh strawberries, hulled and crushed
  • 2 tbsp (30ml) fresh lemon juice
  • 1 packet (38g) powdered fruit pectin (low-sugar version)
  • 2 ½ cups (500g) granulated sugar
  • ¼ tsp (1.5g) unsalted butter

Instructions:

  1. Combine the diced rhubarb and crushed strawberries in a large, heavy-bottomed stockpot.
  2. Stir in the lemon juice and butter, then allow the fruit to sit for 10 minutes to release natural juices.
  3. Whisk the powdered fruit pectin into the fruit mixture until completely dissolved.
  4. Increase heat to medium-high and bring the mixture to a full, rolling boil.
  5. Gradually stir in the granulated sugar, return the mixture to a rolling boil, and stir constantly.
  6. Continue cooking until the mixture reaches 220°F (104°C) on a digital thermometer.
  7. Perform the plate test: drop a small spoonful of jam onto a chilled plate; if it wrinkles when pushed after 30 seconds, it is set.
  8. Remove from heat and skim off any remaining foam from the surface.
  9. Ladle the hot jam into sterilized half-pint canning jars, leaving ¼ inch of headspace.