You can find oyster mushrooms growing in groups on dead or rotting logs. They are often used in cooking. They taste great in food and can smell fishy, but their gills aren’t straight, which makes them a favorite among picky eaters. Oysters are also known to help lower cholesterol. If you are unsure about their health benefits, read on.
As a professional chef, I’ve cooked with mushrooms of all varieties countless times. I know they can be an amazing addition to soups, sauces, entrees and more when fresh. But occasionally, I’ve opened a package of mushrooms and gotten an unpleasant surprise – the fungi smelled strongly of fish!
This fishy odor can be off-putting when you just want to slice up some tasty mushrooms. Why does this happen? After investigating, I’ve learned the likely causes and how to tell if your mushrooms are still usable or not when this fish smell appears. Let’s get into the details!
Three Main Causes of the Fishy Scent
Through my research and personal experience, I’ve found a few key reasons you might notice a fishy or seafood-like smell from mushrooms:
1. Spoilage – If stored too long, mushrooms can rot and take on fishy notes from bacterial growth.
2 Varietal Traits – Some specific species like oyster mushrooms naturally have an odor reminiscent of the sea
3. Storage Conditions – Being near seafood or absorbent packaging may impart ocean aromas.
Let’s explore these causes in more depth so you know what’s going on with your ‘shrooms!
Spoilage Explained
The most common reason for a fishy scent is mushrooms going bad. As fresh produce high in moisture content, mushrooms are prone to quick spoilage from uncontrolled bacteria and fungal growth.
If stored improperly for too long, mushrooms will begin rotting and giving off fishy compounds as the proteins and sugars break down from microbes. It’s the same process that makes old meat smell rancid.
Once a mushroom starts smelling like fish from spoilage, it’s unsafe to eat and should be discarded. The odor means it’s well past prime condition. Don’t risk getting sick!
Certain Varietal Traits
However, not all fishy mushroom smells mean spoilage! Some types like oyster mushrooms have a naturally briny, seafood-like scent even when perfectly fresh. It’s just part of their varietal characteristics.
For instance, the yellow oyster mushroom is prized for its scent reminiscent of a breeze off the ocean. So don’t be afraid to cook up your oyster mushrooms even if they seem fishy at first sniff. Their aroma mellows substantially during cooking.
Impact of Storage Conditions
Finally, improper storage near strong odors can cause mushrooms to take on aromas like fish from their environment. Storing mushrooms beside seafood or absorbing packaging may lend unwelcome scents.
To avoid this, keep mushrooms away from other produce and meat with strong odors, and use paper or cloth bags that won’t impart smells. Then any fishiness is more likely from the mushroom itself, not external factors.
Can You Use Fishy-Smelling Mushrooms?
Whether mushrooms that smell like fish are safe to eat or not depends on the cause. Here are some guidelines:
-
Spoiled mushrooms should be discarded – the odor means they’re rotted and unsafe. Don’t risk eating them!
-
Naturally fishy varieties are fine – varietal traits like oyster mushrooms’ seafood smell diminish with cooking.
-
Storage-related fishiness can be washed away – a quick rinse and towel dry removes external scents if the mushroom seems otherwise fresh.
When in doubt, be safe and throw it out. But mushrooms from today’s grocery run likely just picked up scents from storage and are usable if they pass other freshness tests.
Signs Mushrooms Have Gone Bad
To tell if your fishy mushrooms are spoiled or still usable, look for other signs of decay:
-
Slimy texture – Fresh mushrooms feel slightly damp but not slippery. Any slime indicates spoilage.
-
Wrinkled caps – Dehydration and wrinkling show age. A few minor wrinkles are okay.
-
Dark or dull color – Healthy mushrooms look vibrant, not faded.
-
Spongy feel – Rotten mushrooms get soft and hollow inside versus firm when fresh.
-
Mold – Any fuzz, spots or growth means toss immediately!
-
Strong bad odor – Aside from the fishiness, spoiled mushrooms smell unpleasantly sour or bitter.
If you notice any of these beyond just the fishy scent, don’t use the mushrooms. Their freshness and safety can’t be guaranteed. When unsure, you’re better off throwing them out and starting fresh.
Can Cooking Eliminate the Fish Smell?
If the mushroom passes the freshness tests and the fishy smell seems to just be a natural varietal trait, you can usually eliminate any unpleasant aromas by thoroughly cooking the mushrooms.
Methods like sauteing, boiling, steaming, roasting or grilling will all mask and mellow out the fishiness substantially. The Maillard browning reaction and high heat temper any odors.
If the mushroom still smells strongly fishy after cooking, then spoilage is likely the cause and it should be discarded. But natural varietal scents tend to disappear with proper preparation.
Why Certain Mushrooms Smell Fishy When Fresh
Now that you know some mushrooms naturally have a seafood-like scent, you may be wondering why certain varieties like oyster mushrooms evolved this trait.
After researching the science, I discovered some fascinating explanations:
-
Oyster mushrooms grow on decaying wood, so the fishy scent attracts insects that aid decomposition and spreading of the mushrooms’ spores.
-
The smell comes from chemical compounds like ethanethiol that contain sulfur, which is also present in seafood.
-
Sulfur compounds may have antimicrobial properties to protect the mushroom against competitors.
-
For some species, the fishy metabolites may attract animals who then spread the spores through their droppings.
So generally, the fishy smell helps the mushrooms proliferate in various ways! It’s not harmful, just an unusual quirk of certain mushroom species.
Quick Guide to Popular Mushroom Types
To get your bearings on the mushroom varieties you’re most likely to encounter, here’s a quick reference guide to some of the most common types and their traits:
White button mushrooms – Most widely eaten mushroom in the US. Have mild flavor and firm texture. Great in almost any dish.
Cremini – A more mature brown version of white buttons with deeper flavor. Heartier and excellent sautéed.
Portobello – The fully grown and largest form of the button mushroom. Meaty and full of umami.
Oyster mushrooms – Delicate, mild flavor. Shell-shaped caps range in color. Some types naturally smell like fish.
Shiitake – Meaty with rich umami taste. Require removal of tough stems. Good stir-fried.
Enoki – Clustered thin stems with tiny caps. Crunchy texture. Used raw or quick-cooked.
This covers some of the mushroom varieties I use most often in my recipes after considering their distinct traits.
Storing Mushrooms Properly to Avoid Spoilage
Since aging mushrooms often develop a fishy smell from spoilage, proper storage is key to keeping them fresh longer and avoiding excess bacteria growth. Here are my best tips:
-
Keep mushrooms in the refrigerator in a paper (not plastic) bag, or wrapped in a clean towel. This allows airflow.
-
Don’t wash mushrooms until ready to use. Simply brush or wipe away any dirt right before cooking. Extra moisture speeds up decay.
-
Use within 3-5 days for optimal freshness. Cooked mushrooms last a few days longer.
-
Keep mushrooms away from strong odor sources like fish that could impart unwanted smells.
-
Store mushrooms in prime condition in the first place – avoid old, damaged or smelly specimens when buying.
Follow these guidelines to minimize spoilage and enjoy mushrooms at their peak!
The Takeaway
While an unexpected fishy odor can be off-putting, not all mushrooms that smell like the sea have gone bad. With certain varieties, it’s completely normal. And fishy smells from storage often resolve with a quick rinse.
By looking for other signs of spoilage and understanding typical mushroom traits, you can judge whether your fishy fungi are still good to cook. And rest assured that any natural fishiness usually disappears once the mushrooms are cooked.
With proper storage and usage, you can keep mushrooms fresh and harness their amazing umami flavor in all types of cuisine without worrying about a fishy smell ruining the dish. Just remember to play it safe and compost any that seem spoiled.
They smell like anise
Oyster mushrooms smell faintly of anise and are often associated with fishy taste. They are actually called aniseed toadstools and grow near deciduous and coniferous trees. The common name comes from the way the fruiting body looks like a shell, but the smell is very different. This is because oyster mushrooms should be savoury and not have a strong aroma.
The true oyster mushroom is Pleurotus ostreatus, but there are many varieties. The smallest is Pleurotus citrinopileatus, which looks like a cluster of yellow flowers. They smell a bit like fresh watermelon when sauteed in oil and have a distinct anise-like flavor. The mushroom’s spores are airborne and can cause respiratory problems in workers.
Oyster mushrooms form clusters on rotting or fallen logs
Oyster mushrooms are a common find along creeks, rivers, and wooded areas. They grow on dead hardwoods, and often form clusters on logs. They prefer trees that are in shade, such as oak and beech trees. They can also be found on stumps. Their distinctive odor and leathery texture can make them an excellent addition to Asian cooking.
This type of mushroom grows on dead or dying wood and smells fishy. The cap is fan-shaped, and their stems are decurrent and elongated. The mushroom grows in clusters and is easy to recognize. It has a fishy smell and can be found in clusters. It grows at low elevations and is often found on rotting or fallen logs.
Here’s How To Tell If Your Mushrooms Have Gone Bad
Why do mushrooms smell fishy?
Any mushrooms that have a fishy smell are far past the point of no return. This smell is caused by an overwhelming amount of bad bacteria. All ingredients do have some bacteria on their surface. Once the bacteria start multiplying too much, they start showing noticeable signs of their presence. A fishy smell is one of them.
What could be the cause of a strong smell in urine?
Urine odor or strong smell of urine is mainly caused by the number of waste products excreted in the urine. Normally urine will have a slight odor, but the odor will be less if the quantity of water is more than the waste products. Dehydration is the main and usual cause of smelly urine. But certain diseases also can lead to a pungent urine smell. Those are urinary tract infection, uncontrolled type 2 diabetes mellitus, bladder infection, maple syrup disease, and fistula in the urinary tract(abnormal connection of the urinary tract with other organs).
Do mushrooms smell like fish?
Certain mushroom varieties will smell like fish even when they’re fresh. There’s one, the lactifluus volemus, that’s commonly known as the “fishy milkcap.” That should tell you all you need to know about the mushroom’s odor. The smell of fish is drastically reduced after cooking — at least in most cases.
Why do mushrooms smell bad?
Bad mushrooms may give off various strange smells, ranging from ammonia-like odors to sour or fishy smells. When the mushroom ferments and breaks down, it causes the smell. Different bacteria on the mushrooms cause different odors. 7.