Last Updated July 22nd, 2021
One of the biggest complaints about (black) Wood ear mushrooms (Auricularia auricula-judae) I hear is that they smell horrible. In fact, Wood-ears do not have any obvious smell of their own. The pungent and acidic smell is likely fromt too much sulfur dioxide.
Although the pungent smell of sulfur dioxide coming from a pack of Wood-ear mushrooms can be quite concerning, I sometimes choose to “rescue” the package by soaking and washing the wood ear mushrooms, because sulfur dioxide is readily soluble in warm water. Unlike with dried fruits, spices or other preserved food, we can wash wood ears thoroughly without losing the qualities for which wood-ears mushrooms are loved for.
Having said above, the pungent smell (high level of sulfur dioxide) could indicate poorer quality overall. Before “rescuing” the whole pack, I normally soak just a few pieces first, and observe. If the few soaked wood ear mushrooms exhibit all the good quality characteristics (except the smell), soft, succulent, and in their natural ear-shaped form (not broken pieces), I would consider them worth rescuing. Here’s how I do it.
Wash the wood ear in a large container of warm water and change the water frequently until the water is clear and the smell has reduced significantly. If it is a big pack, divide the mushrooms into smaller batches, since the wood-ears will swell up a lot during rehydration. Next, soap the wood-ears in warm water. Change the water every couple of hours until the you can’t detect any acidic smell. At this point, you can decide to continue soak them to fully rehydrate for immediate use, or to air dry and store them for future use. To air dry, pat dry the wood ears with a clean towel, then spread them out on a wire rack and leave in a cool and well-ventilated place until they are dry completely. Now you have a clean batch ready to go. When you need them for a recipe, just soak to rehydrate, or drop them into soups straightaway!