Shake off the beetles and other animals from the flowers and put all the flowers in a pot. Pour boiling water over it and let it steep for 2-3 hours.
Then strain and put in a clean saucepan. Add the citric acid (10 g) and bring to the boil. When the brew is simmering, add the sugar and dissolve it, stir everything well until the brew is clear again.
Pour the syrup into hot bottles and close tightly, then leave to cool.
Pour a dash of syrup into a glass of mineral water and enjoy.