Can rehydrated cloud ear mushrooms (wood ear) be eaten if soaked overnight?

Generally speaking, "yun'er" usually refers to wood ear mushrooms (black fungus). Whether overnight-soaked wood ear mushrooms are edible mainly depends on the storage conditions. If stored at a low temperature, they may still be safe to eat; however, if stored at a higher temperature, they are generally not suitable for consumption.

If the wood ears were soaked in a relatively cool environment—such as at room temperature below 15°C or in a refrigerator—they are typically safe to consume the next day. This is because low temperatures slow down the growth of bacteria, mold, and other microorganisms, reducing the risk of spoilage.

However, if the wood ears were soaked in a warm environment—such as during summer when room temperatures are high—they can easily spoil. Particularly under hot and humid conditions, bacteria and other microbes multiply rapidly, causing the mushrooms to become slimy or develop an unpleasant odor. In such cases, the soaked wood ears should not be eaten after being left overnight.

It is recommended to maintain good hygiene when rehydrating wood ear mushrooms: rinse them thoroughly, use a clean container for soaking, and consume the soaked mushrooms on the same day they are prepared.