I peeked in the cupboard today and gave the tincture jars a vigorous shaking. Then I sent them back to sleep.
I’m about half way through the stash of elderberries in the freezer. Still on my list to try are elderberry syrup and elderberry jam. I decided to try this recipe for elderberry syrup first, choosing it for its use of honey over sugar.
I played around with proportions and the possibility of adding a splash of lemon juice or vinegar, as in these two recipes. The following are some variables I considered.
Juicer or sieve: I boiled the berries and pushed through a fine mesh sieve. The remaining juice, I cooked down with honey and lemon, then poured off half of it to make one jar of light syrup. The remaining berry corpses I sent through the juicer, and added the seedless product to the other half of light syrup. This made for a syrup with more body.
Pulp or not: no pulp this round, it went into the compost. I’ll have to commit to a laborious process of de-stemming if I’m going to try a jam.
Honey or sugar: honey, no question.
How sweet: I went more sweet on the light syrup, a little less sweet on the fuller bodied version. Both have a slight bitterness, which may be from the trace stems or from sitting overnight in a steel pot. Both are less sweet than the recipe. Because I’m a wuss about sugars?
Add acid, lemon or vinegar: Yes to acid. I used the juice of one lemon in the light syrup and an additional 1/4c of cider vinegar in the second round.
Make it tonic with alcohol: I didn’t try it this time. Maybe next round, or in the bottling of the syrup as gifts. Perhaps I’ll try a bit of elderberry tincture as the added alcohol.
Round one is jarred and sealed. I’ve got roughly 3lbs of frozen berries to de-stem before the next round.

I’m somewhat ashamed to admit that I’ve never had an elderberry… Perhaps there’s a Japanese variety?
Also: are you planning to use the syrup for medicinal uses? Culinary? Both?
From what I could find with a quick search, there are a few varieties of Japanese elderberries, both black and red. Look for the black ones, as most of the reds are toxic. Elders tend to ripen mid-late summer, but you can also gather the flowers for tea, jams, and wine. Do let me know if you find any in your own experiments.
The syrup’s for both medicine and pleasure, though honestly, mostly for pleasure with a gesture toward medicine.