4 litres hot water700g sugar
Juice and zest of four lemons
2 tablespoons white wine vinegar
About 15 blooming elderflower heads (I freeze mine to kill bugs as well as to store for making later)
A pinch of dried yeast
Put the hot water and sugar into a large container (I used a bucket from poundland) and stir until the sugar dissolves, then top up with cold water so you have 6 litres of liquid in total.
Add the lemon juice and zest, the vinegar and the flower heads and stir gently.
Cover with something like a clean cloth/tea towel and leave to ferment in a cool, airy place for a couple of days. Take a look at the brew at this point, and if it’s not becoming a little foamy and obviously beginning to ferment, add a pinch of yeast.
Leave the mixture to ferment, again covered with cloth, for a further four days. Strain the liquid through a sieve lined with muslin and pour into sterilised plastic bottles (a good deal of pressure can build up inside as the fermenting brew produces carbon dioxide, so plastic bottles previously used for fizzy drinks are essential).
Seal and leave to ferment in the bottles for at least a week before serving, chilled. The champagne should keep in the bottles for several months. Store in a cool, dry place.