Pre sterilise your jam jars (see above for more info on this), and keep them warm.

Bring the water to the boil in a large pan.

Remove the pan from the heat and add the elderflowers and lemon. Cover with a clean tea towel and let sit for a minimum of 1 hour, or a maximum of 24 hours.

Place a sieve over a large pan. Line the sieve with a clean piece of muslin, then pour the contents of the first pan into the sieve.

Let the flowers and lemons drip through into the pan below. You can gather up the muslin and squeeze the contents firmly to extract the juice, or you can leave it for several hours to slowly drip through.

Add the jam sugar to the pan of juice, and bring to a boil.

Stir well until the sugar has dissolved.

Boil the syrup hard, for 4 minutes. Keep an eye on it the whole time and reduce the heat a little if it looks like it may boil over.

Remove the pan from the heat and skim off any scum with a clean spoon.

Very carefully, pour the contents into the waiting sterile, warm jars. If your jars are cold they may shatter with the heat of the syrup.

Let the jam cool fully somewhere safe before popping on the sterile lids and storing the jars in your pantry or gifting to friends.