Around our place in NE Pennsylvania we harvest now or perhaps within the next week or so.
We hope they are as ripe and dark as possible by now. Husband and I harvest together, one holds the bucket and the other snips with a scissor the umbels as tight as possible so you don't have so much on stems in there, and drop it straight into the bucket underneath.
Coming home, I flood the bucket a couple of times with water to have bugs and debris If any, floating to the top. Then transfer the whole washed lot, stems and all to a pot. I do not add any liquid at all through the entire process.
I take a potatomasher and mash already a little while starting very gently some heat under the pot. Continue to mash occasionally and heat until everything is bubbling, then stop. I pour the whole thing into a bag made especially for that and hang it over a bowl. The unadulterated clean juice collects in the bowl. I squeeze with all my might the leftover stuff in the bag and then discard whatever is left, which is skins, seeds and stems.
Now I follow the instruction on the Pectin box, but never add as much sugar as they ask for. I simply measure the amount of juice and then calculate how much sugar and Pectin I need to add. Boil the whole thing with the added Pectin and pour boiling hot into superclean glasses and close up. I turn the filled glasses once over /upside down, then stand them right up again. I have never gone through the "heat again canning process". I stop right here and wait for the telltale pop as the vacuum is created. It always works.
Now my Elderberries never produce a true jelly this way, but it becomes the most delicious superconcentrated syrup. I have never lost a glass due to spoilage and nobody ever got sick from doing it this way, I have been using this procedure for ca 20 years. ( I was told this is unsafe only recently....)
It is most delicious on waffles, ice cream yoghurt and such.
Ursula