Cooking With Moldy Mushrooms

Cooking With Moldy Mushrooms

In the world of food, mold can be both a blessing and a curse. Some of your favorite foods may be molds such as dry-aged steaks, artisanal salami or brie cheese.

On the other hand, mold is the culprit for throwing away many items that go bad in the refrigerator or cupboard. However, if food goes moldy does that mean you have to throw it out immediately? 

What is mold?  

Molds are a microscopic fungi. Mold isn’t always dangerous though. Many of your favorite foods might actually be mold or certain medicines like penicillin.

However, some molds can be very dangerous to your respiratory system and cause problems with breathing and some molds can even be poisonous if ingested.

In most cases, removing visible mold does not make something edible because mold can grow invisible on roots that can work their way deep into food.  

How do I tell if my mushrooms went bad? 

If the mushrooms have dark, blotchy, wet spots they are on their way to becoming rotten. Once they become slimy and have extreme color change, it indicated that there is bacterial growth on the surface and the mushroom should be discarded.

 If the mushrooms start to smell fishy or sour, steer clear! If you’re buying packaged mushrooms, visually check the package. If the package is wet inside or contain any decaying or mushy mushrooms, don’t buy it.  

Is eating moldy mushrooms safe? 

If your whole package of mushrooms becomes slimy it is best to just throw it out. Eating mushrooms that have gone bad can cause food poisoning or nausea. They can also cause serious stomach pains. If there are only a couple mushrooms that have become slimy, throw them out and inspect the rest of the mushrooms.

Rinsing the mushrooms that are still okay gives you a chance to check each mushroom! However, as the old saying goes, when in doubt, throw it out.  

Can you get food poisoning from old mushrooms? 

Yes, eating old mushrooms can give you food poisoning or at the very least make you nauseas and give you an upset stomach.

You may also run the risk of botulism; which is a serious illness caused by a toxin that attacks the body’s nerves. 

How long do mushrooms last? 

Fresh whole mushrooms can be kept for 10 days in the fridge, while fresh sliced mushrooms can last up to 7 days. Cooked mushrooms can last for between 7-10 days. Whole mushrooms keep better than the sliced ones.

The sliced ones are exposed to air making them decompose faster. Loose mushrooms should be kept in a plastic bag that is partially sealed. This will help the gases escape from the bag. Avoid washing the mushrooms before storing them.  

How should I store my mushrooms? 

The conditions in which mushrooms are packaged and stored can also contribute to the growth of harmful bacteria. Storing fresh mushrooms unrefrigerated in an airtight container may promote the growth of harmful bacteria that could cause botulism. 

Mushrooms have some respiratory capabilities even after being picked. The best way to store them is to put them in the refrigerator in a light, thin brown paper bag which will allow them to breathe. The ideal temperature for mushroom storage is 34 degrees which is close to the temperature of many refrigerators 

 Is it safe to eat mushrooms with white fuzz?  

If you notice a fine white fuzz, don’t worry. Once mushrooms are removed from their cool environment they grow in, they release their spores which rapid grow into a white fuzz which is called mycelium. It’s completely safe and edible! However, if it does make you a little uneasy you can always trim it off!  

Can I cook with mushrooms that have gone slimy? 

A slimy mushroom is a red flag when it comes to mushrooms. If you catch it early enough, cook them right away and you may be able to get another day or two out of your mushrooms

 In fact, some chefs like mushrooms that are slightly discolored because they are more mature which in return means they have a more mature taste. Once the slime starts, they will become darker in color and have a mushy texture which indicates mold. 

Does mold die when cooked? 

The high heat of cooking will kill the bacteria that has grown however, it will not destroy any toxins they may have excreted. Raw mushrooms may contain a naturally-occurring toxin called agaritine which is deactivated by heat. When boiled in water for one hour, you can lose up to 88% of the agaritine found in mushrooms.  


 “Food safety tips for mushrooms.” The government of Canada. December 5, 2019.  

“How to tell when mushrooms are bad.” Cooking Light. October 20, 2016. 

Myers, Dan. “It’s actually OK to eat these foods if they’re moldy.” The Daily Meal. June 28, 2019.  

“Raw mushrooms are not dangerous. Eat them.” Happy Herbivore. May 11, 2017  

“Slightly off-color mushrooms are safe to eat.” Chicago Tribune. September 3, 2018.