Elderberry pith is soft and malleable. Although it has largely been replaced by more modern materials, elderberry pith enjoyed a number of uses before those materials were available. It was often used to make small toys. The Danish soaked the pith in oil and used it as a candle wick. Some removed the soft pith and used hollowed-out elderberry canes as pipes or even pop guns.
Identify a sizable elderberry stem. Grasp it between your fingers and squeeze it. If the twig is spongy and slightly resistant, there is healthy pithy wood inside.
Prune the elderberry stem. Use a pair of sharpened, disinfected pruning shears and make the cut at the elderberry stem's point of origin.
Examine the cut portion of the stem. Inside the thin ring of woody tissue there is a lighter-colored interior that fills the middle of the stem. This spongy material is the pith. In common elderberry, it is white. In red elderberry plants, it is brown.