What does the fruit of the red elderberry tastes like?

I do not know what the fruit of the red elderberry tastes like, but the Korean name for the treelike shrub is 말오줌나무, which translates as "horse piss tree."

The stems, roots, and foliage of the red elderberry are supposedly poisonous and the berries toxic when eaten raw, but, according to Wikipedia, the fruit is reportedly safe to eat when cooked and is used in native American recipes. The shrub has also been used as a medicinal plant, so I can imagine a Korean kid with a cough or cold saying, "Mom, this medicine tastes like horse piss."