Can tremella be eaten directly after soaking in cold water?

Generally speaking, tremella (white fungus) soaked in cold water should not be eaten directly. The detailed explanation is as follows:

Tremella soaked in cold water has only absorbed water and expanded but may still harbor bacteria, mold, and other microorganisms inside. Eating it raw can easily cause gastrointestinal discomfort, leading to symptoms such as abdominal pain and diarrhea. Additionally, the nutritional components in raw tremella are tightly structured, making them difficult for the human body to fully digest and absorb, thus failing to deliver their full nutritional value. Moreover, if soaked for a prolonged period in cold water under warm environmental conditions, tremella may become contaminated with Pseudomonas cocovenenans, which poses a risk of producing harmful toxins. Therefore, it must never be consumed without cooking.

After soaking, tremella should be thoroughly rinsed under running water, and the tough stem portion should be removed. Then place it in a pot, cover with sufficient water, bring to a boil over high heat, and simmer over low heat for 20–30 minutes until the texture becomes soft, tender, and translucent. It is recommended to use warm water for soaking to shorten the soaking time and reduce bacterial growth due to prolonged immersion. If not cooked immediately after soaking, store the tremella submerged in water in the refrigerator and cook within 24 hours. Before consumption, reheat thoroughly to ensure food safety.