Method
Boil 2 litres water and pour into large bowl. Add 2.4kg sugar and stir until dissolved. When warm but not steaming add 50 elderflower heads, 4 lemons zested and sliced, and 100g citric acid. Cover with a tea towel. Stir twice a day for two days with a very clean spoon. After two days sterilise bottles and strain through muslin into a jug. Bottle the cordial. Keep up to 1 month in fridge or freeze.