Dip elderflower head gently in water and then add to saucepan.

Add water, sliced lemon and tartaric acid into the saucepan and then bring to the boil. Take off the heat and leave overnight, covered.

The next day, remove as much of the lemon and elderflower as possible using tongs and discard.

Add sugar to the mixture in the saucepan and stir over low heat to dissolve. Then bring to the boil and remove from heat immediately once it boils.

Allow to cool.

Strain using muslin cloth, pour into sterilised bottles and seal with lids.