Nine to 10 Days From Packaging Date
According to Mountain View Mushrooms, fresh mushrooms can be stored at 34 to 40 degrees F for up to 10 days from the date of packaging. If purchasing store-bought mushrooms, the packaging date will be printed on the storage container or plastic wrap.
According to the Virginia Cooperative Extension's Food Storage Guidelines for Consumers, fresh mushrooms should be kept in the refrigerator for no more than two days after purchase.
The USDA states that mushrooms can be stored for two to three days after purchase. If mushrooms appear excessively dry or slimy, are soft, or have turned a dark color, they should be discarded regardless of the date of purchase or packaging.