In the meantime, while the insects are moving out, take 1 kg (2 pounds) of sugar and 1 litre (2 pints) of water. Mix the two and bring the mixture to the boil. You can substitute half of the sugar with honey. If you like experimenting with tastes add some slices of ginger and one or two sliced lemons (or limes). Boil for 2-3 minutes and let it cool down. When the syrup is almost tepid pour it into a big jar and add the black elder inflorescences into it, stir gently and cover with a lid. Let it stay like that for 3-4 days stirring once a day. On the forth day strain the inflorescences which you can throw away or use in the garden compost pile.
You can save some of the aromatic syrup to prepare drinks but first you need to boil it again and then bottle . If you venture to move one step farther then you have to mix the syrup with at least half a litre of pure spirit. Mix them thoroughly and immediately pour the raw liqueur into dark glass bottles and seal tightly. And now comes the most difficult period: waiting. My advice is - forget about those bottles and deal with some other urgent work in the garden. Two or three months is enough for the liquor to become adolescent, but its full magic reveals only when it matures. I do not want to tell you the real time span but believe me it is worth waiting for.
The elderflower liqueur is never clear because of the pollen. This is the only flaw of this powerful potion which we quickly tend to forget right after the first shot.