Do dried mushrooms need washing?

Dried mushrooms do need to be cleaned, and they also need to be rehydrated. You can accomplish both things at once.

To rehydrate dried mushrooms: Rinse the mushrooms quickly, place them in a bowl, and cover with warm water. Let them sit for 15 minutes or until they’ve softened. Lift the mushrooms out of the water carefully, allowing any grit to settle to the bottom of the bowl, then strain the flavorful soaking liquid through a coffee filter and save it to add flavor to sauces and stocks. If you’re using shiitake, wood ears, or other mushrooms that have tough stems, trim them away and discard.