Shake out the elder flowers well and cut into small “florets”, removing coarse stems in the process. Wash the lemons well and cut them into slices.
Boil the water with sugar until the liquid is clear. Then let it cool down again. Dissolve the citric acid in the cooled sugar water.
Place the elder flowers in a suitable container with the lemon slices and pour the sugar water over them. Leave this mixture in a cool, dark place for 5 days.
Then strain and fill into sterilized bottles, close them tightly and store in a cool place.