1 liter of water
700 g sugar
1 tablespoon pectin
6 g of agar agar
Clean the elderflower bunches from all impurities, such as insects, larvae, dead flowers and leaves. Rinse under cold water and transfer into a large bowl (I had a ceramic 4-liter bowl). Pour over 3 liters of cold water.
Wash the lemons very carefully. Cut them into slices and then in half-moons. Add to the elderflowers. Stir in the citric acid (I don’t use any). Place the bowl in the refrigerator for 24 hours or in a cool place, covering it with a piece of gauze to avoid curious insect visits.
The next day, place a strainer over another large bowl and line it with 2-3 layers of gauze. Transfer the elderflowers and lemons in it. Make a bundle and squeeze it tight so as to extract the maximum of its juice. Then throw away the bundle. Filter the water in which the elderflowers soaked overnight through another piece of gauze, pouring it in the first filtered concentrate.
Transfer the elderflower juice in a saucepan. Add the sugar, agar-agar and pectin. For the last two, you can either sprinkle them in small doses through a fine sieve (directly over the juice) or dilute them in a small amount of syrup and then add to the lage volume. Bring to a boil over low heat, stirring regularly. Check with a drop on a cold plate, if the jelly is ready. If the drop freezes rather quickly, stop boiling. This can extend up to 10 minutes.
Pour the elderflowe jelly in warm, clean jars. While the liquid is piping hot, seal the jars tightly and let cool. Then store the jars in a dry and dark place. After opening, refrigerate.