Wash the rhubarb and cut off the ends. Now cut the rhubarb stalks into small pieces without peeling.
Wash the lemon and rub off the skin. Now halve and squeeze the juice. Halve the Vanilla pod and scratch out the seeds.
Put the rhubarb, vanilla pod and seeds, lemon juice and peel in a saucepan and mix with the sugar. Put the lid on it and let stand overnight.
The next day add the water and bring to a boil. Reduce the temperature and simmer for about 15 minutes.
Put the rhubarb aside and let it rest for at least 2 hours.
Then pass through a very fine sieve and catch the syrup.
Fill the syrup in a large bottle for immediate use and refrigerate. So it is about 14 days preserved.
Or preserve for the shelf in small glasses/bottles.