Here's a recipe for lovely drinking all through the Summer:
40 heads Elderflower - picked in full sun to get the best flavour
60g citric acid
2 lemons juice and rind
3 lbs white sugar
3 pints boiling water
(also 1 plastic bucket and tea towel to cover, bottles)
Put all the ingredients into a clean plastic bucket and leave for 5 days. Stir occasionally if you feel like it. Strain through a fine sieve or muslin and bottle. This can also be frozen (which is why we're only just finishing last year's batch) just remember to leave an expansion gap in the bottles, or freeze into ice cube trays - this makes the ideal size to defrost in a glass of fizzy water for a most refreshing drink.
Dilute to taste.
PS Also quite fun to take small people out when picking the flowers for their and your entertainment thus: Mummy, you forgot to put your trousers on - those nettles will make your legs hurt.