There are lots of recipes that you can adapt to your taste. Here’s a basic one, but don’t worry about being too precise with quantities.
5 litres water
6 heads of elderflower
2 tablespoons of vinegar (cider or white wine)
You’ll also need a clean bucket for fermenting and bottles.
Pick the elderflowers when it’s sunny and they’re young.
Put the sugar in the bucket and pour on about 2 litres (a kettle) of boiling water to dissolve it. Add the remaining 3 litres of cold water.
Add the sliced lemons and the vinegar.
Give the flower heads a shake to remove the insect life, but do not wash them.
Remove the large green stalks and put the flowers in the water – it’s their natural yeasts that will make it fizzy.
Cover with a clean cloth and leave for 48 hours.
Strain the liquid through a sieve or muslin into the bottles. Screw on the caps and leave at room temperature for about 2 weeks.
Refrigerate and drink.
The drink is very mildly alcoholic.
Smell your elderflowers before picking them as some can have a distinct note of cat pee!