Have you added other foods to make the soup together? If not, I suggest you remove the water from the first soup. As you said, Wuyishan Ganoderma thinks it may be that your Ganoderma has gone bad and has a strong sour taste. Most of the reasons are that Ganoderma lucidum has not been preserved well and has become damp. If the sourness is very light, you can feel free to take it. Certain trace elements contained in Ganoderma have a slightly sour taste. If live Ganoderma is boiled in water, the sourness will be stronger.