Elderberry flavor

[Scadsobees]

I'm trying out elderberry for the first time in my life.  I've collected a whole bunch with the plan to make some jam and some elderberry mead.

I cleaned a bunch of them and boiled them to extract the juice so that I can use that for some jelly.  Boiled for a while (<1hr) and ran it through a strainer to get the juice. 
The juice tastes terrible!!  Very bitter and not a ton of flavor, quite thick and very pretty.  I added a bunch of sugar to a sample, and that took away the bitterness, but the flavor isn't much.

Is this normal for elderberries?  The jelly recipes call for some lemon juice (assuming for more tartness).  Did I perhaps pick these too soon (I picked 3 batches within about 3 weeks).

Thanks for any input you might have.

Rick