Peel the rhubarb, then weigh 2400 g and place in a large saucepan. Add the raspberries and let them cook. Divide the vanilla pod, scrape out the pulp and add it to the saucepan, also add the lemon juice.
Bring everything to the boil, remove the vanilla pod, then puree everything with the hand blender. Now add the sugar (mixed with Gelierfix 3: 1) and cook for at least 5 minutes while stirring constantly.
Then immediately pour into the prepared jars, put the lid on and let cool on the head.