Why Does Fish Smell Like Ammonia? Here’s How To Handle The Problem

fish smells like ammonia

After a night leaving uncooked seafood in the fridge, you take it out and realize that it has an unpleasant smell like ammonia.

You are not sure whether you should throw it out or still use it.

You are wondering the factors that cause the smell and worry they can damage your health?

In this article, we will clarify your concerns such as: what causes fish to smell like ammonia, whether it is safe or not eating ammonia-smell fish, and how to get rid of that bad smell.

Keep reading to find out.

Why does fish smell like ammonia?

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Fish has a naturally salty and fishy scent of the ocean. But when it comes to the bad odor, it’s another story.

According to Moment of Science, there is an odorless substance called trimethylamine oxide found in fish tissue.

When the fish is killed, the fish tissue is exposed to air, and the bacteria in the fish’s body breaks down this chemical into two new chemicals that are derivatives of ammonia, and therefore smell pretty bad.

That ‘muddy’ odor seems similar to the ammonia smell.

Does ammonia smell like fish?

Yes, ammonia does have a fishy smell to it.

This is because ammonia is produced by the breakdown of fish waste material.

Ammonia is also present in small amounts in our urine and sweat, which is why it can often smells like when we don’t shower for a few days!

Even though the smell of fish may not be pleasant to some people, it’s actually an important indicator that your aquarium is healthy.

A strong fishy smell could mean that there is too much waste build-up in your tank and you should do a water change soon.

Is it safe to eat fish that smells like ammonia?

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Although fish that has been caught for a little while might not have the most pleasing fragrance, it doesn’t mean that it has gone bad or cannot be eaten.

Based on the smell and the fish appearance, you can determine if the fish is still good to eat or not:

  • Good-to-eat fish has a slightly fishy smell, the flesh is shiny and firm with red gills, and spring back when pressed. Also, the eyes should be clear and bulge.
  • If the fish smells like ammonia, the flesh is mushy and turns gray. When you see that the fish edges are dry and darkening, it’s time to throw it away.

Will ammonia smelling fish make you sick?

Ammonia smelling fish can make you sick, but it’s not the fish itself that’s the problem.

It’s actually the bacteria that live in some types of fish that produce ammonia.

These bacteria are usually harmless, but they can cause problems if they get into your food or water supply.

You can avoid getting sick from ammonia smelling fish by cooking them properly and by making sure to clean all surfaces where you’re going to prepare them.

You should also avoid eating raw fish, and make sure to wash your hands thoroughly after handling any fish.

What happens if you eat fish that smells like ammonia?

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Ammonia is a very toxic compound that can be harmful to your health.

If you eat fish that smells like ammonia, it means that the fish has been allowed to decay and the ammonia level in the fish has become extremely high.

This could potentially make you very ill.

If you eat fish that smells like ammonia, it’s likely that the fish is contaminated with bacteria that produce the unpleasant smell.

These bacteria can cause food poisoning, which may result in nausea, vomiting, and diarrhea.

In some cases, food poisoning may be serious enough to require hospital treatment.

Why fish smells like ammonia after cooking – cooked fish smells like ammonia?

You might not notice the differences between the slight fishy smell of uncooked seafood, and the sour, rancid odor of spoiled uncooked seafood.

However, you will realize the differences when it is cooked. If the bad odor is still there or even stronger than before,  do not eat it.

What if frozen fish smells like ammonia?

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If frozen fish smells like ammonia, it may have gone bad.

Ammonia is a gas that is released when protein breaks down.

This gas can cause rotting and make the fish smell unpleasant.

If the frozen fish smells like ammonia, it’s best to discard it.

Depending on how long the fish has been stored, there may be signs of spoilage such as discoloration, sliminess, or a change in texture.

If you’re not sure whether the fish is bad or not, it’s always better to be safe than sorry and throw it away.

How to get rid of ammonia smell in fish?

The best way for having a fish dish without the fishy odor is to cook it right after it is caught.

By doing this, your dish is not only juicy, but also has the aroma of fresh seafood.

Another effective way to avoid the stinky fish is to keep them flash-frozen, though the flavor is not as good as the freshly caught fish.

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Put fish on ice or in the fridge soon after you buy it and use it within 2 days after purchasing.

If you want to store it longer, wrap them with plastic foil to keep it moist and put it in the freezer.

You can also consider covering the fish with squeezed lemon juice before cooking it for reducing the odors or soaking your fish into milk for 20 minutes and rinsing it real good under the water prior cooking.

The protein in milk will help to extract the compounds that cause fishy odor out of the fish. This method is not recommended for those who are allergic with milk.

Once the fish is cooked and flavored with sauces and spices, the fishy smell won’t annoy you anymore.


Besides the above tips, what you should do is to find a reliable fishmonger and try to buy the fresh caught fish, or pay close attention to the quality when purchasing fish.

Avoid eating raw fish and researching more about tips to preserve cooked fish.

The bottom line is that you should make an effort to care about what you eat so that you and your family can safely enjoy the fine taste and good nutrition of seafood and avoid food poisoning.

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