Pick the oddly bitter, nutrient-dense berries just before they're fully ripe (now), or the birds will beat you to them. If using them for the first time, try eating a couple dozen sprinkled over vanilla ice cream for dessert. Eaten in excess, the raw berries have a laxative effect, so only take a handful or so at a time.
Elderberries are eaten fresh, dried, made into jelly and jam, juiced, tinctured, and made into syrup, wine or excelsior. The richest antiviral and immune stimulating properties are found in the berries and skin, so I like to throw them in the blender. To preserve the blended berries, add 95% grain alcohol (Everclear) in a ratio of 1 part alcohol to 4 parts elder juice, and they will last all winter in the refrigerator. Use liberally when viral illness first comes on, especially flu symptoms at first onset.
Some elderberry extracts have shown activity to disable virus' ability to bind to human cells, effectively sterilizing the cold and flu virus: this is why one must take it at the very onset of symptoms. Often, by the time a person feels the symptoms of cold, their body has already destroyed the virus. The symptoms are a result of the inflammation response to the viral replication; elderberry also has inflammatory properties related to its antioxidant effects that modulate inflammation in the immune response, reducing cold symptoms. In influenza, elder speeds the course of the virus and reduces the agony. (Note: Dr. Oz includes the elderberry among his five superfood immunity boosters.)
The blended berries, once strained, may also be frozen into ice cubes for preservation. In therapeutic use, I prefer the syrup with echinacea, lemon and ginger juice.
You can cook the berries without compromising their virtues; I suggest a low simmer, and using honey to make a syrup.
While the berries have mild fever reducing qualities, the fever reducing quality is stronger in the flowers, which are safe for infants and geriatrics and may be taken internally or made into a bath. The flowers are also made into a champagne. The flowers bear their own naturally occurring wild yeasts. Elder tincture is best when made in the spring with the flowers, then used to extract the berries in fall.
Elder stems are hollow, and are traditionally fashioned into pipestems. The leaves are fairly toxic, but not deadly. The plant loves wet soils, and I planted these in almost every project I worked on with the Plantsmen nursery in upstate NY. We put them along drainage areas with native echinaceas, geraniums, and goldenrod.