Put the elderflower in a large bowl with the lemon skin and rose petals. Pour over the boiling water and press down the florets, making sure they’re submerged. Leave to cool, then cover the bowl and leave to infuse at room temperature for about 36 hours.

Strain the infusion into a medium saucepan, pressing against the flowers with the back of a spoon, to release all the liquid, and discard flowers, branches and rose petals. Add the sugar and lemon juice to the infusion, then turn on the heat to high and cook for three to four minutes, stirring, until the sugar has dissolved, and the liquid is starting to simmer. Take off the heat, leave to cool, then pour into a sterilised bottle, seal and store in the fridge.