Food Safety Focus (200th Issue, March 2023)– Article 4

Soaking Mushrooms and Food Safety

Dried mushrooms such as wood’s ear, jelly fungus and flower mushroom are widely used in dish preparation. It is common to soak dried mushrooms in water before using them in a dish. Soaking them increases water content of dried mushrooms, which could lead to proliferation of bacteria when left at room temperature for a prolonged period of time. Some bacteria are disease-causing and could lead to foodborne illnesses, and some can even produce toxins.

Upon preparation, wash dried mushrooms under clean running water before transferring them in clean containers for soaking. Avoid soaking too many mushrooms all at once. The time for soaking mushrooms at room temperature generally should be no more than two hours, otherwise they should be kept in the refrigerator. Mushrooms that have been soaked should be used and consumed as soon as possible. Discard mushrooms if slime or abnormal smells are found after soaking.