There is no authoritative basis for stating how long the black fungus has been soaked for poisonous, which may be related to the soaking temperature and the number of flora in the dried fungus itself. It is recommended to consume soaked black fungus in a timely manner. There is no clear data on how long black fungus can be soaked will be toxic. As a common food, fungus itself does not have toxins and does not transform into toxins. Generally speaking, if black fungus is soaked for too long, it may be contaminated by bacteria, leading to the proliferation of bacteria, which can produce toxins. In addition, soaking black fungus for a long period of time may also lead to deterioration of black fungus and the production of off-flavors and toxins. In short, there is no authoritative scientific basis for how long the black fungus is soaked for toxicity. The discomfort after consuming the fungus may be related to the soaking time, temperature, and deterioration of the fungus. It is recommended to consume black fungus in time after soaking to avoid damage to the organism. It should be noted that the people who are allergic to black fungus are prohibited from consuming fungus to prevent allergic symptoms such as generalized itching and skin rashes.