For the mixture, put the elderflowers in the preparation grain, carefully mix in the lemon slices. Leave the mixture in a dark place for 14 days.
Then strain the mixture. Set aside the drained elderflowers until further use.
Boil a syrup from water, sugar and vinegar.
Combine the elderflower mixture with the syrup and mix everything well. Bottle the liquid and add the set aside elderflowers again.
Let the liqueur mature for about 2 months.