Found this ~
Blue elderberries may be dried and stored for later use in pies,
puddings, sauces, etc. The simplest method of drying them is to tie a
few cluster stems together with medium-weight string and suspend them
over spread newspaper in a moisture-free area for 7-8 days. Remove the
dried berries from the stems and store them in tightly covered
containers. An alternative method is to remove the elderberries from
the stems and spread them on a cookie sheet. Dry in an oven set at its
lowest temperature for 24 hours.
From Darcy Williamson, Donnelly, Idaho, "How to Prepare Common Wild Foods"