Today, I harvested a couple of bags of these flowers to make elderflower liqueur. Easy, snip them off into a grocery bag, However, some of the other plants in the ditch are not so friendly --I waded through tall wild parsnip (which can cause horrible blistery burns), prickly thistles, and lush poison ivy to obtain my prize. I wore long pants and my muck boots. Don't harvest ALL of the flowers--you will also want there to be plenty of elderberries later this summer!
Remove the blossom from the stems, which purportedly contain a toxin. I started out snipping the flowers off with a scissors, but ended up stripping the blossoms off the stems with my fingers. It takes a lot more umbrels than you expect, once you remove the flowers from the stems. I filled a 2-qt mason jar with the blossoms, but you could make any amount. The blossoms are then covered with vodka. I purchased Prairie Vodka because it is sort of local (SW Minnesota) and is organic, plus it was on sale for a reasonable price. When I purchased the vodka, I asked if they sold elderflower liqueur and they do! It is a very pricey liqueur called "St. Germain. "
This is my first time making elderflower liqueur, so I don't have any more advice or insights yet--but I did find a yummy-sounding recipe for Elderflower Mojitos that i can't wait to try when the liqueur is ready in a few weeks!