Begin by adding a plate to the freezer which you will use to
test the jam later.
Wash and trim the edges of your rhubarb. Weigh after cutting
into chunks.
Add the rhubarb chunks to a large saucepan with an equal
amount of jam sugar and 1 tbsp vanilla bean paste. You may double this recipe
for a larger batch. Mix continuously on a gentle heat until the sugar has
dissolved (approximately 7-10 minutes).
Add the juice of half a lemon and increase to a medium-high heat.
Continue mixing occasionally, skimming off the foam and allowing the jam to
boil (set a timer when you increase the heat).
After 12-15 minutes of
boiling, add a spoonful of jam to the frozen plate to test the consistency. If
your jam is ready, it will not run down the plate, will hold its shape, and
will wrinkle when pushing a finger through the cooled spoonful (a sugar
thermometer inserted into the saucepan of jam should reach 105c). If the jam isn’t ready,
continue cooking for two-minute intervals, testing in between, and stirring
frequently.
Leave the jam to cool for 20 minutes before adding to
thoroughly sterilised jam jars. Seal and store in a cool, dark place or
refrigerator.
Notes
Sterilise your jam jars and lids by boiling in a large pot of water or washing with hot soapy water before drying in a low oven. If using a dishwasher, run the jars and lids through a hot dishwasher cycle and leave to dry.
