Jim,
Do you know what kind of Elderberry you have? Does it have purple,
almost black berries? I grow both Sambucus canadensis and Sambucus nigra
and we NEVER have elderberry goo. From the sound of your problem, could you
be growing something else?
My experience with elderberry "goo" was with berries that were carefully
cleaned from the stems. The goo was so obnoxious and impossible to clean
that I threw out the carboy because it was unusable.