1. Carefully wash 150 g of elderflowers.
2. Bring 1 L of water containing 1 kg of sugar to the boil, then leave to cool down.
3. Add the elderflowers and 25 g of citric acid to the sugar water. Leave in a dark, cool place for three days.
4. Prepare the bottles in which to store the syrup. Pour the elderflower syrup through a sieve and then pour into the bottles.
5. To conserve the syrup, add a few drops of alcohol (80% ABV) and then set alight.