I'm sorry to tell you that the dried fungus you bought was soaked in some medicine before, otherwise the normal fungus wouldn't smell, and it wouldn't go bad after being dried for a long time. I'll teach you a simple method. You use a small white bowl to soak dried fungus in hot water. The soaked pure fungus is yellow with a little black, and the chemically treated fungus is green or dark black. I hope I can help you.