Normally there will be no tea smell.

The color of fresh slide mushrooms is normal yellow, with no sign of whitishness or too yellow, and their shapes and sizes are similar, with no obvious difference. There are no black spots on the outside either. If you find that the color of the mushroom is abnormal, some are whitish or there are some black spots inside, it means that the mushroom may be spoiled and you cannot buy this mushroom.

You can also tell whether the mushrooms have gone bad by smelling them. Fresh mushrooms smell like they have a faint aroma, which is derived from mushrooms. If the aroma smells abnormal, with a rancid or sour smell, then this kind of mushroom must be spoiled.