Put the strawberry juice with the preserving sugar and the juice of the lemon in a tall saucepan. Scrape out the pulp of the vanilla pod and mix in. The vanilla pod can also be cooked.
Bring to the boil, stirring over high heat, until everything is bubbly. Then cook for 4 minutes, stirring constantly. After the gelling test, pour directly into jars that have been rinsed with hot water.
Of course, 2: 1 jam sugar can also be used, then please adjust the amount of juice or amount of sugar.