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Mushrooms Smell Fishy: Are They Safe to Eat?

Fishy-smelling mushrooms: Are they a culinary quirk or a cause for concern over food safety? Here’s the full scoop.

So you opened your fridge to grab some mushrooms and—guess what—the mushrooms smell fishy!

Or maybe you already cooked the mushrooms, and you came here wondering why your meal smells more like fried fish from a buffet in Vegas and less like mushrooms sautéed in your frying pan.

Whatever brought you here, welcome! And stick around, because if you read on, we’re going to dive into why mushrooms sometimes smell fishy and why that probably means they’re no longer safe to eat.

Why Oyster Mushrooms Smell Fishy

Some mushrooms smell fishy because, well, that’s just how they smell!

Take oyster mushrooms as an example. In Mushrooms Demystified, American mycologist David Arora describes the oyster mushroom as having a “superb fishy texture and taste.” In fact, one of the reasons oyster mushrooms are called what they are is because they smell very much like fresh oysters from the beach.

And so, when it comes to fishy oyster mushrooms, the takeaway is this: If your oyster mushrooms have a fishy smell but they’ve been stored correctly and don’t show signs of spoilage, they should be generally safe to eat.

Are Mushrooms That Smell Fishy Safe to Eat?

Okay, you got the scoop on oyster mushrooms.

But if you have a different kind of mushroom in your fridge and it smells fishy, then what?

If you have mushrooms in your fridge that aren’t meant to smell fishy but do, they’ve probably gone bad. Unfortunately, it’s best to throw them away for food safety reasons.

Mushrooms can go bad, especially if they’re sliced or diced, not stored right, or kept for too long.1Brennan, M. H., B.Sc., Ph.D., M.I.F.S.T., & Gormley, T. R., , B.Sc., Ph.D., F.I.F.S.T.I. (1998). Extending the Shelf Life of Fresh Sliced Mushrooms (p. 2). The National Food Centre. And when mushrooms go bad, they can sometimes smell fishy because of bad bacteria. Discard them and don’t cook or eat them; they can give you an upset stomach or food poisoning.

This is particularly important if you, or someone you cook for, are more likely to get food poisoning. The Centers for Disease Control and Prevention says this includes seniors 65 and older, kids under 5, pregnant women and their babies, and anyone with a weak immune system (meaning those who are sick or recovering from an illness).2Centers for Disease Control and Prevention (2023, July 13). Factors That Increase Your Risk of Food Poisoning. Food Safety. Retrieved August 7, 2023, from https://www.cdc.gov/foodsafety/people-at-risk-food-poisoning.html

Selecting and Storing Your Mushrooms Properly

An article from the Harvard T. Chan School of Public Health suggests selecting mushrooms that have firm, evenly-textured caps. The institution says that mushrooms should be stored in the fridge, where they will keep for up to a week, and yet nevertheless recommends using them as soon as possible.

To refrigerate your mushrooms properly:

  1. Keep The Mushrooms Dry: Moisture encourages the growth of mold or bacteria, which is why wet mushrooms tend to get slimy or moldy. If the mushrooms are wet, dry them with a paper towel before storing them in the fridge.
  2. Use Paper Bags: Put mushrooms in a paper bag in the fridge. It helps soak up extra wetness and, unlike plastic bags, allows the mushrooms to breathe.
  3. No Plastic Bags: Plastic bags make mushrooms go bad faster because they hold in moisture. If you do have to use plastic bags because you don’t have paper bags at home, make sure they are loosely wrapped.
  4. Look at Them Daily: Check your mushrooms every day. If any look bad, take them out and throw them away.
  5. Keep Cut Mushrooms Sealed: If you cut mushrooms, put them in a sealed container so they don’t dry out.

And if you have too many mushrooms, think about other methods of preservation. For instance, you can blanch and freeze them to use later. Other mushrooms preservation methods include canning, drying, and pickling.

Can Spoiled Mushrooms Make You Sick?

Don’t eat mushrooms if you think they’re spoiled. Even safe-to-eat mushrooms can make you sick if they’ve gone bad.3 Wennig, R., Eyer, F., Schaper, A., Zilker, T., & Andresen-Streichert, H. (2020). Mushroom Poisoning. Deutsches Arzteblatt international, 117(42), 701–708. https://doi.org/10.3238/arztebl.2020.0701

Despite what many home cooks believe, cooking spoiled mushrooms doesn’t make them any safer to eat. While heat can kill harmful bacteria, some bacteria produce toxins that can withstand the heat and still cause food poisoning.

Don’t take chances with your health. Every year, 48 million Americans get sick from food. Beyond the potential for high medical bills, the numbers are alarming: out of those 48 million, 128,000 end up in the hospital and 3,000 lose their lives.4Centers for Disease Control and Prevention (2018, November 5). Burden of Foodborne Illness: Overview. Estimates of Foodborne Illness in the United States. Retrieved August 6, 2023, from https://www.cdc.gov/foodborneburden/estimates-overview.html

Bottom Line

When it comes to mushrooms, trust your senses and knowledge. Whether you’ve got the distinct oyster mushrooms or another variety, a fishy scent can be a telltale sign of their freshness—or lack thereof.

Remember to store them right, keep them dry, and consume them promptly. In the kitchen, it’s always better to play it safe than sorry. After all, the well-being of you and your loved ones is on the line.

Enjoy your mushrooms, but always prioritize health and safety first.

Know your author

Written by

Dim is a food writer, cookbook author, and the editor of Home Cook World. His first book, Cooking Methods & Techniques, was published in 2022. He is a certified food handler with Level 1 and Level 2 Certificates in Food Hygiene and Safety for Catering, and a trained cook with a Level 3 Professional Chef Diploma.