5 Signs Your Mushrooms Have Gone Bad

Mushrooms are a great ingredient to add earthy, umami-rich flavor to salads, stir-fries, sauces, and other recipes. Many home cooks turn to the meaty texture of mushroom varieties like portobello or cremini for meatless meal substitutions.

We are all mindful of the price tag when choosing produce, and there’s nothing more disappointing than finding a package of withered mushrooms in the fridge that haven’t been stored properly. They have a short shelf life which calls for quality selection and storage.

Selecting Fresh Mushrooms

Fresh mushrooms are dry, firm, and smooth with a pleasantly earthy smell. Soft, mushy, shriveled or possibly slimy mushrooms are not the best choices.

Mushrooms in a supermarket are often imported and have been transported from a considerable distance. They might also be improperly displayed in a store which can further accelerate their spoilage. Avoid the pre-packaged containers of mushrooms; try and find loose mushrooms so you can inspect their quality yourself.

Never hold mushrooms under running water to clean like other vegetables as this will dilute the taste and ruin the structure and texture of the mushroom.

How to Tell if Mushrooms are Bad

When you’re in the produce section of your store or strolling the farmers’ market on a warm day, how do you know if the mushrooms you are selecting are at the peak of freshness?

Appearance alone can tell you a lot when looking at the choices of fungi. If the mushrooms have bruises or dark spots, look slimy and wet, or are slightly darker in color than usual, they are starting to go bad.

The surfaces of the mushroom should be dry and appear plump. A closed veil under the mushroom cap indicates a delicate flavor, while an open veil and exposed gills mean a richer taste.

Not all mushrooms that are looking a bit less than picture-perfect need to be passed over. Ask yourself — are they being sliced as fresh ingredients in a salad or cooked in a pot of soup?

Can You Still Eat Slimy Mushrooms?

The number one rule of thumb when it comes to detecting freshness is that when mushrooms are slimy, they’re no longer ideal for use. Sliminess occurs when mushrooms have been stored incorrectly or allowed to linger in the fridge for too long— it’s a clear sign that the mushrooms are beginning to spoil.

However, if the slime is the only sign of going bad, you might still be able to redeem your mushrooms. If they are just starting to lose freshness they can be salvaged by being cooked in soups, sauces, or maybe in a pot of chili.

But, if your mushrooms exhibit other signs of decomposition, you should avoid them completely. If the mushrooms have also developed an unpleasant odor, they should not be used. Bad mushrooms can make you sick due to bacteria that has started to form.

How to Properly Store Mushrooms

After you bring your mushroom purchase home, take the time to store them correctly to avoid food waste.

If you can only get mushrooms in a container at your local market, the first step you want to do to preserve freshness is to take them out of the original container.

Why is the container not good for storage?

A package of mushrooms that goes straight from the grocery store to the refrigerator will result in mushrooms that will collect moisture on the surface and start to discolor and turn brown after five to seven days. A thin layer of slime will begin to form and can lead to mold.

This method might be fine for shorter storage, and it’s certainly the easiest method, but the lack of air flow with the plastic wrap will cause rapid spoilage.

When mushrooms are transferred from their original container to a brown paper bag and set it in the fridge, the brown paper bag will keep any moisture at bay.

What about a paper towel in the paper bag with the mushrooms?

This method will produce mushrooms after a ten-day stay in the fridge with no slimy surface. The combination of paper towel and paper bag can work to cut down on extra moisture, which means the mushrooms won’t get slimy. Mushrooms in a paper towel-lined paper bag will produce slightly better results than those in an unlined paper bag.

How Long Do Mushrooms Last in the Fridge?

Avoid plastic bags and sealed containers when storing mushrooms as the lack of air flow will speed any spoilage. Whole, raw mushrooms will keep for approximately four to seven days in the refrigerator. Sliced mushrooms stored the same way will last about 2-3 days.

Remember to store mushrooms to keep moisture away from them and prep right before you are ready to serve.


  • What Are Cremini Mushrooms?
  • Should You Wash Mushrooms You’re Going to Cook?
  • What Are Morel Mushrooms and How Do You Cook With Them?