How To Tell If Tilapia Is Bad?

Tilapia is a freshwater fish that’s available and delicious all year long, unlike trout that’s tastiest during the summer and haddock that’s at its best in the fall.

Tilapia is a great fish for frying, steaming, baking, and even soups. Unfortunately, like many other foods that sit in the fridge, tilapia isn’t resistant to spoiling. 

Distinguishing good from bad tilapia involves assessing its appearance, smell, and texture. Fresh tilapia should have a clear, slightly pinkish flesh, and a clean ocean-like smell; any sour or overly “fishy” odor indicates spoilage. The flesh should be firm and spring back when pressed, not sticky or slimy, which are signs of decay. Additionally, if the tilapia’s eyes are cloudy and its gills are not a bright red or pink, it’s a sign that the fish is no longer fresh and should not be consumed.

There certainly are ways you can preserve your tilapia so you can keep it fresh longer. In this article, we’ll go over in detail how to spot spoiled tilapia and what the best methods are for keeping your filet tasty and cookable. 

How To Tell If Tilapia Is Bad When Raw

Tilapia is generally light in flavor and has an amazing taste even the pickiest fish eaters will enjoy. However, that enjoyment can be ruined by a bad tilapia filet.

Key Point

You can always tell tilapia has spoiled in the refrigerator if it has a fishy smell that’s fishier than normal, has a milky or slimy coating, or the filet is oozing. 

Fishier Smell Than Normal

Freshwater fish have a very distinct fishy smell, but when refrigerated tilapia goes bad, it smells even more fishy than normal.

When good, it should smell sea-fresh. The smell that comes from tilapia is a result of an amino-based substance called trimethylamine NH (CH3).

It’s a prominent chemical with 66-116mg of it in 100g of tilapia, so this makes the fishy smell unavoidable. 

When the tilapia is damaged, the refrigerated fish’s smell will be very different. When a full tilapia body is spoiled, its immune system will cease and bacteria will be free to multiply. 

The fat and intestines in the abdomen will rot the quickest and produce a terrible smell.

Additionally, the trimethylamine and carbon monoxide on the fish during decomposition will cause an even more unpleasant odor.   


Tilapia skin and meat have a mucus covering that’s secreted by glandular cells. Not only that, but the fish is rich in immunoglobulins, lectin, and hemolysis. 

The skin on the fish is similar to an immune substance that helps avoid bacteria, small organisms, and parasites that may be lurking in the water. That’s why it’s so easy to spot bad tilapia purely by looking at its flesh. 

When you remove the skin of the tilapia, you may notice that it has more of a pale color rather than a luster. The fish will also bend in downward if you pick it up from the middle.

Additionally, if you press on the center of the body before you skin it if the flesh is loose and doesn’t stick to the bones, the fish is most likely spoiled. The meat may be a little sticky and slimy as well

Not only that, but if the fish has been spoiled for a while, if you press your finger into its body, the skin will sink into a hole that won’t bounce back and will remain in the snape of your finger. 


If it’s reached the point of no return, you’ll notice that the scales will peel off and will have a pale, sticky, and non-shiny look to it.

Depending on how long the tilapia has been spoiled, you may notice mucus that’s being secreted from its gills.

If you open the gills, the secretions of mucus will have an unpleasant odor.

Oozing fish
Oozing fish


When it’s spoiled, tilapia will turn brown. Additionally, it will show signs of darkening, discoloration, and drying around the edges when spoiled. 

Fresh tilapia will have a red color to its flesh and a clear, shiny eye. If the fish is processed, the fillet will be pinkish-white in color and will turn white when cooked. The fillets should also have red bloodlines and will be elastic when pressed on. 

However, there are several factors that can affect the appearance of the fish such as color fixative.

Carbon monoxide can change the fish’s color. This helps keep the fish fresher for longer and maintains a bright red color. 

How Long Can Tilapia Stay Fresh In The Refrigerator or Freezer?

Properly cut and skinned tilapia stays fresh in the refrigerator for 1-2 days. You can keep the fish in its original packaging to extend shelf life, but it has to be used within 24-hours after its expiration date.

The temperature of your refrigerator should remain constant and cold at 32 degrees Fahrenheit. 

If you plan to freeze your tilapia, it will maintain ideal quality for 6 to 8 months. It will remain good after that time, but the quality may go down. For best quality, keep your freezer at 0 degrees Fahrenheit for indefinite safety. 

Once you take it out to thaw, it can be kept in the refrigerator for 1 to 2 days before cooking.

If it was thawed in the microwave or cold water, it has to be cooked immediately. 

Tilapia frozen
Frozen Tilapia

How Long Is Cooked Tilapia Good In The Refrigerator?

Cooked tilapia can be stored in a refrigerator for 3 to 4 days before needing to be thrown out.  

The tilapia should be stored in a shallow airtight container that’s also wrapped tightly with heavy-duty aluminum foil or cling wrap. The better it’s sealed, the better it will taste when eaten again.  

How Long Is Taliapia Good For At Room Temperature?

At room temperature, tilapia is only good for about 90-minutes before it begins to rapidly decompose.

It will become foul and soft. According to the FDA, bacteria are strongly active starting at 40 degrees Fahrenheit. 

At average room temperature, it will be around 75 degrees Fahrenheit. This is plenty warm enough to cause bacteria growth on tilapia.

At this point, you are now exposing yourself to food poisoning and other health issues if you eat it. 

Can I Eat Spoiled Tilapia?

You should never eat spoiled fish of any kind, especially if it’s raw. If you eat spoiled tilapia, you put yourself at risk of ciguatera and scombroid poisoning.

These are two types of food poisoning you can get from eating spoiled fish. 

Ciguatera Poisoning

Fortunately, this type of poisoning is more concentrated in the internal organs of the fish, which most people don’t eat when it comes to tilapia.

You are less likely to get ciguatera poisoning than you are scombroid poisoning. Ciguatera poisoning can cause nausea, vomiting, diarrhea, and abdominal cramps.

If left untreated, the symptoms can progress to muscle aches, headache, numbness of the skin, itching, tingling, numbness of the lips, tongue, or area around the mouth.

You may even notice a metallic taste in your mouth or feel like your teeth are loose.

Scombroid Poisoning

You can get scombroid poisoning from any fish that hasn’t been refrigerated properly.

Symptoms of this poisoning can develop 20 to 30 minutes after you’ve eaten the fish. You may feel flushing in your face, nausea, experience vomiting, hives, and abdominal pain. 

This is more minor than ciguatera poisoning and may feel more like an allergic reaction, but it doesn’t necessarily mean you’re allergic to fish. 

Room Temperature75°F90-minutes
Frozen0°F6-8 months
Fresh32°F1-2 days
Cooked32°F3-4 days

Is Smelly Fish Safe to Eat?

Smelly fish is certainly safe to eat as long as it’s not expired. FIshy odors begin as soon as they are caught and killed because of the bacteria on the surface.

It begins to break down trimethylamine oxide into smelly trimethylamine. As long as the flesh is firm and the skin is shiny rather than sticky or slimy, the fish is still safe to eat. 

What If It Smells Like Ammonia?

If the uncooked tilapia is spoiled, it can have an ammonia odor to it. The odor will become stronger after you cook it.

It’s similar to spoiled ground beef. It smells fine before you cook it but the ammonia odor comes out as it cooks.

If the odor is sour, rancid, fishy, either cooked or raw, never eat it. 

Can You Eat Expired Frozen Tilapia?

Yes, you can eat expired frozen tilapia as long as it has been kept at 0 degrees Fahrenheit and doesn’t show signs of spoilage. You can tell it’s bad if it has whitish or grayish-brown flakes or patches on it.

This is called freezer burn. You’ll see it at the edges of the fish or over the surface. This means the fish has dried out.

Additionally, if the fish is lighter than it was when it went in the freezer, it’s a sign that moisture has evaporated from it.  

Final Thoughts 

It’s important that you know how to spot spoiled tilapia. In doing so, you can stop yourself from being exposed to food poisoning or other health issues.

Tilapia that is brown in color, smells fishier than it should, has ooze coming from it, or isn’t elastic shouldn’t be consumed raw or cooked. 

Overall, tilapia is a great affordable fish that cooks well in various settings when fresh.

It contains a high percentage of protein, omega 6s, fatty acids, omega 3s, and is rich in nutrients that are responsible for a healthy heart. The flavor isn’t too fishy and it doesn’t contain toxins that are dangerous to humans.

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