How to check if fresh mushrooms have gone bad

If fresh mushrooms become sticky, discolored, have a strange odor, or have blackened gills, they may have gone bad. Fresh mushrooms should have a dry surface, uniform color, and compact texture. Deterioration may be caused by improper storage, microbial contamination, oxidation reactions, water loss, or mechanical damage.

Fresh mushrooms secrete mucus on their surface when they spoil, and they feel smooth when touched, which is a typical manifestation of bacterial reproduction. The cap of a normal mushroom is white or light brown in color. If there are large areas of yellow, green, or black spots, it is not edible. The transformation of gills from white to dark brown or black is also a sign of decay, and can emit a sour or moldy odor. When storing, avoid sealing plastic bags and use paper bags for refrigeration to delay spoilage. Pay attention to checking whether the mushroom roots are dry and free of mold when purchasing.

Some varieties, such as shiitake mushrooms, have obvious curled and cracked edges on the cap when they spoil, while enoki mushrooms exhibit a soft and easily breakable stem. If wild mushrooms are not processed in a timely manner after collection, they are more prone to spoilage and should be refrigerated within 6 hours. If there are water droplets or mist inside the packaging bag of mushrooms in commercial packaging, it may have grown mold. Eating spoiled mushrooms by mistake may cause gastrointestinal discomfort, and symptoms such as abdominal pain and diarrhea require timely medical attention. Before cooking, mushrooms can be soaked in light salt water to observe if they float, and those that sink are relatively fresh.

For daily storage of fresh mushrooms, it is recommended to wrap them in kitchen paper and place them in a breathable container to avoid humid environments. Before cooking, check the appearance and odor again. Mushrooms that have slightly deteriorated may still retain toxins even when heated at high temperatures. Wild mushrooms should be identified by professionals and should not be consumed if the species is unclear. Mushrooms are rich in protein and minerals, but their nutritional value is lost and there is a safety risk after spoilage. If any abnormalities are found, they should be promptly discarded.