Peel the rhubarb sticks and cut into 1 cm pieces. Peel the lemons first with the peeler and than press the lemons.
Boil up water in a pot with a little salt and blanch the lemon peels for about 1 minute. Then cut into narrow strips. Place the rhubarb pieces with the lemon juice, the strips and the gelling sugar into a large pot and bring to a boil with stirring.
Cook for 4 minutes, make a gelling test, then pour into small jam jars.