How to Tell if Tilapia is Bad [Definitive Guide]

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Available year-round, tilapia is a great choice of fish to use for a variety of dishes; baked, grilled, fried, steamed, sautéed, or even in soups.

But, do you know how to tell if your tilapia is bad? Can you read the signs, or know when to keep or discard it?

This article will cover all the ways you can tell your tilapia is going bad and other common questions people have on tilapia spoiling.

How to Tell if Tilapia is Bad

As mentioned above, Tilapia is incredibly versatile to cook with, and is the perfect fish for those fussy non-fish eaters, as its flavour is so light it’s almost non-existent.

But, whilst this fish variety is beloved by many, it also has a few key differences to other fish you may have bought and stored.

Let’s start by talking about buying fresh Tilapia, and what you should look for:


Fresh fish should be quite stiff, the flesh resistant to the pressure of a finger poking it.

In the case of Tilapia, the skin should also look a little funky, as it is usually covered in a protective film or mucus – the fish secretes it to protect it from water-borne organisms that would cause it harm.

Now, it’s worth remembering that the film mentioned above should ONLY be on the skin, not on the flesh of the fish or fish fillet.

Once the skin is removed, the flesh should be firm, with glossy flakes of muscle, and if you poke it gently with your finger, the indentation should vanish quickly.

Another note to keep is the colour of the meat itself. Raw fillets will have visible red bloodlines or veins, and the flesh will be a pinkish-white colour, this will change to completely white once cooked.

But do note, one side of the fish will be slightly darker, as this is the side that the skin was on.


Fresh fish, including Tilapia, should never have any sort of fluid oozing from it or be sitting in it in the case of pre-packaged fish.

Whilst fillets of Tilapia, or the whole fish, can often be sold with the skin on and film membrane intact, there should never be any runny liquids pooling around the fish or fillet.


Any seafood, including fish from both salt and freshwater, should smell fresh – that means no ‘fishy’ smell. You should smell nothing but a faint hint of fish and whatever waters it came from. Tilapia is no different.

That bad smell is caused by various internal parts of the fish’s body breaking down over time, and this produces that overly ‘fishy’ smell. So, if the fish you’re selecting smells fishy, or just not clean like it’s come from the water within hours, don’t buy it, because it’s anything but fresh!


Firm flakes, and a stiff body, with clear eyes; these are key signs to judging the freshness of any whole fish. But, when buying a filleted fish, it’s not really any different.

Whilst you may not have a whole fish to test – for rigidity – the fillets should still have some stiffness, and the flakes are firm and resist pressure from a poking finger.

If the flake falls apart, or your finger makes a mark that doesn’t soon disappear, the fish is old and not suitable to buy.


How long has that Tilapia been on ice, or in the fridge? It might surprise you to know that you shouldn’t keep fish chilled for long periods and that it can still go bad in your fridge.

Many people believe that as long as the fish is kept airtight and cold, in a fridge, that it will keep indefinitely. This is wrong, and a sure-fire way to spoil the fish.

Instead, only eat your Tilapia as freshly as possible, the same day you buy it is best, and if you must keep it, do so only for 1-2 days. If you need to keep it longer than this, you’re better to freeze it – see the guide below.

But, what if you’ve already bought your Tilapia, and now you need to know if it’s safe to eat? Here’s a quick breakdown of what to look for:

How to Tell if Tilapia is Bad When Raw

First of all, use the key signs from the above to check, and on top of that, check the ‘Use By’ date, if there is one. Fish is generally not safe to eat 24hrs past the ‘Use By’ date, as it will begin to spoil soon thereafter.

How to Tell if Tilapia is Bad When Cooked

Cooked Tilapia should be a milky-white colour, have next to no ‘fishy’ smell or flavour, and the flakes are firm and not mushy.

It can keep for 3-4 days at below 4˚C/39˚F in your refrigerator, past this, it should be discarded.

Cooked Tilapia that has spoiled can also have a sour smell, the flakes of cooked flesh can be slimy, and generally look flat or dull in colour.

If the cooked Tilapia deviates from these signs, you should exercise caution and discard it.

How to Tell if Tilapia is Bad When Frozen

According to the FDA, any food that has been reliably kept at or below 0˚C/32˚F will keep indefinitely.

However, the method of storage will affect the Tilapia, and this will be covered in the storage section of this article.

How do you tell if your frozen Tilapia is bad? You can usually see signs of freezer burn; discolouring of the flesh into a chalky-white colour that sits on top of the natural or expected colour.

The length of time in the freezer is also a good indicator; a maximum of 12-months, past this, is unwise.

Frozen Tilapia that has spoiled and been thawed will have the appearance of spoiled raw fish, see signs of above.

Any spoiled fish should be discarded immediately.

How Long Does Tilapia Last

So now you have your fish, from a fishmonger or from a supermarket, how long do you think it will last? Depending on where you keep it, the times can vary a lot, read on to find out more:

In the Fridge

Any fish will keep in your fridge for 1-2-days below 4˚C/39˚F, past this, it is unwise to eat the fish, as it may have spoiled, but not be showing clear signs yet.

It’s far safer to purchase and enjoy your fish fresh or use pre-packaged fish well before the ‘Use By’ date.

In the Freezer

In a freezer that is kept permanently at 0˚C/32˚F, any food including Tilapia, will keep indefinitely.

However, as most freezers will fluctuate as they are opened and closed, it is wiser to not keep your Tilapia for 6-9-months, or for longer than 12-months.

On the Countertop

Fish turns rapidly once it is above 4˚C/39˚F, and this happens quickly at room temperature.

As a general rule, ideally, any fish should not be left at room temperature (average of 25˚C/77˚F) for any longer than 70-minutes, and an absolute maximum of 90-minutes.  

Fish left for longer than this are prone to rapid spoilage, and consumption of spoiled fish can lead to severe gastroenterological illness, or worse in some cases.

Any fish that is left out for longer than 90-minutes at room temperature should be discarded. 

How to Store Tilapia

To start with, regardless of whether it’s in your fridge, freezer, or countertop, you want to keep your Tilapia in an airtight container. But, what do you do with it after that?

In the Fridge

Tucked safely into the back of your fridge, where it’s consistently cooler, your whole or filleted Tilapia will keep for 1-2 days with no further storage instructions.

Try not to leave your fish, or other delicate foods, near the front of the fridge, as the opening and closing of the door will affect the temperature, and cause spoilage due to temperature changes.

However, you can also use the airtight container to marinade or infuse some flavours into the fish just before cooking, just make sure your fish is still fresh before doing this!

In the Freezer

Any fish should not be placed directly onto frozen surfaces, as this can lead to freezer burn and cause the fish to spoil.

Instead, wrap it in a couple of layers of greaseproof paper, or thick plastic (like old bread bags), and then in a suitable freezer-proof airtight container.

This will ensure the sub-zero temperatures don’t adversely affect the fish.

You can also freeze your Tilapia fillets with herbs and spices, as a kind of slow infusion. Then cook when thawed for great flavourful fish.

On the Countertop

As mentioned in the above paragraph, leaving any fish on a countertop for long periods is unsafe. But, it is fine to do so just before cooking.

As the fish’s temperature heads towards 4˚C/32˚F and above, this is a prime time to infuse with herbs and spices.

Just make sure you cook the fish as soon as possible and keep it airtight in the meantime.

To Sum Up

Tilapia is a wonderfully versatile fish and provided you keep it below 4˚C/32˚F in your fridge, it’ll hold for a couple of days.

You can also store it in your freezer for 6-9-months quite safely. Just remember to keep it airtight, and don’t leave it at room temperature for more than 70-minutes.