Sort through the Elderflowers, looking for dirt and bugs. I didn't wash mine (didn't want to wash away any flavour) instead I shook mine over a bowl to dislodge any unwanted stowaways. Cut any thick stems off the elderflowers, and add to a big pot. Slice the lemons and add, along with the citric acid. Don't add the sugar!
Measure out 2 litres of water and add to the pot, then gently over a medium heat bring to boiling point (this should take a while). As soon as the pot starts to boil remove from the heat. Cover, and leave to seep for at least 5 hours (or overnight, I seeped mine for 8 hours). The longer you leave it the stronger the elderflower flavour.
This is a good stage to sterilise the glass bottles and pouring equipment. You could put yours through the dishwasher on the baby-bottle wash setting (or highest temp possible). Otherwise, wash the bottles with hot, soapy water. Line a baking tray with baking paper and place the bottles on there with space between, Heat for 15 minutes at 120 degrees. Wait until they are cool to remove from the oven. Boil the lids to the bottles (or jars) in water to sterilise them. Please be careful!
When the elderflower is seeped, place a sieve over a large pot. Use the tea-towel or muslin to cover the sieve. Pour the elderflower mix through the sieve and press out, to strain the liquid (you could use your hands, I find the back of a wooden spoon works well if you don't want messy hands)!
Add the sugar to the strained elderflower liquid. Over a medium heat bring this to the boil, when it is boiling turn the heat down and let it simmer for 10 minutes.
Whilst the cordial is warm pour into the bottles and seal. If you are using a funnel or pouring aid make sure that is sterilised too. When it is chilled serve diluted with water, ice and some lemon. Enjoy in the sun!
