The next usable part of the plant are Elderberries. Harvest the berries when they are fully ripe (deep purple not red) in late August. They will be round and plump, and hanging off the branches in large, heavy clusters. Elderberries cannot be eaten raw, therefore they must be dried before consumption. The easiest method for drying them it to hang the berry clusters on a string in a warm, dry place. I usually dry them in the attic where the air is always warm in the middle of the summer. When dried remove the stems and store them in airtight glass jars in a dark place.
The most tasty herbal teas for me come from Elder plant. When the shrub is in full bloom (May/June) and on a warm dry sunny day find an Elder plant away from polluting roads. Harvest only healthy looking flower heads without black plant lice. Pick them carefully as they are very easily damaged, I tend to collect them into a paper bag to avoid squashing them on the way home. Lay the flowers out on a paper to dry in a warm, well ventilated place. When thoroughly dry, store the flowers and pollen (the best part) in airtight glass jars in a dark place, for up to a year.