I just had to spread the knowledge. I dearly hope it doesn’t taste of whatever it is the name suggests.

My newly found great Chinese English Dictionary NCIKU suggest: heimuer lu – Juice of black edible fungus

So where did they get this name from? I have tried looking up wood-ear fungus on Wikipedia, and there is no reference to anything to do with Judaism.

However a search on Wikipedia for ‘jew ear‘ did come up with this:
Auricularia auricula-judae (syn. Auricularia auricula, Hirneola auricula-judae) is commonly known as Judas’s ear fungus or Jew’s Ear, the name from which it derives the “judae” in its scientific name, or as the jelly ear fungus. It was said that Judas hanged himself on an elder tree, which is the origin of the name. The term ‘Jew’s Meat’ was a deprecatory term used for all fungi in the Middle Ages.