How to tell if Cooked Fish is Bad

How To Tell If Cooked Fish Is Bad

Fish is a favorite for so many people, and rightfully so. It is a yummy centerpiece for so many dishes and a great source of nutrition for anybody who chooses to eat it.

But one thing that everyone can agree on, even the biggest of fish lovers included, is that fish smells.

The smell calms down a little once it is cooked, but raw fish is incredibly pungent. There is only one thing that can out-smell the stench of raw fish and that is the smell of cooked fish that has gone bad.

It is incredibly unpleasant, and perhaps even enough to put some people off eating fish again. 

While it is easy to tell when raw fish has gone bad, this becomes more difficult when the fish is cooked.

But there is no need to worry because we’ve put together this handy guide which you can use to tell if the fish that you cooked earlier has turned or not.

The last thing that you want is to become unwell because you ate fish that passed its best, so follow this guide to ensure that this never happens. 

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Check the Sell-by Date 

The first method we recommend to check that your cooked fish hasn’t turned is to check the sell-by date. This might seem incredibly obvious, or you might find yourself thinking that this method will only work with raw fish. But this is not the case.

Fish does not last well when it is raw, and because of this, it is very common for people to purchase fish ready-cooked from the grocery store. It is also common for people to purchase raw fish but to cook it immediately upon they return home to avoid the fish turning before they wish to eat it. 

This is why checking the sell-by date is very important. If you have bought fish ready-cooked, the sell-by or use-by date will be stated clearly on the packaging of the fish.

If you have bought raw fish then cooked it, you must make a note of the sell-by or use-by date for you to determine when you will need to use the fish by. Even though cooking the fish will prolong its shelf life, cooked fish still does not have a very long shelf life when stored in the refrigerator.

This is why a lot of people opt for freezing their fish so that it will be edible for longer. 

When kept in the refrigerator, cooked fish will be safe to eat for up to 6 days. However, this will only happen if the fish is stored properly. If you have bought the fish cooked you can simply store it in its original packaging.

Whereas if you have cooked raw fish, you should keep it in an airtight container until you wish to use it. However, just because cooked fish should last up to 6 days in the refrigerator doesn’t mean that it will.

So to determine if your cooked fish is bad, you should use some other methods as well as checking the sell-by date to ensure it is safe to eat. 

Do an Assessment 

The next method of checking whether or not your fish has turned is an incredibly common method used to see if all manner of food is safe to eat.

For this method, all you need to do is look at the fish. If your fish has turned there are some common signs that you can watch out for which will confirm this.

First, let’s start with cooked fish that has been frozen to prolong its shelf life. A lot of people believe that freezing something extends its shelf life indefinitely, however, even food that has been frozen will go off after a certain period.

Cooked fish will be good to eat for up to 9 months when frozen, but after this, you will notice some common signs that it is not safe to eat. The main one being the freezer burns on the fish. To look for freezer burn, you should check the surface of the fish.

If your fish is experiencing freezer burn it will have crystallized patches of ice along the surface of the fish. While fish that has freezer burn is still technically safe to eat, it is highly unlikely that you will enjoy eating it and so the best thing to do is throw the fish out. 

You will also be able to tell if cooked fish that hasn’t been frozen has gone off by checking the surface of it. If cooked fish has turned, it is common for the color of it to change.

Fish meat is usually a pink or white color with a clear coating over the surface of it, however, as it turns the fish will start to look a lot milkier. It is also common for fish to turn a blue or grey color as it goes bad.

If you observe either of these color changes, you should not eat the fish as it has likely turned. 

It is a common misconception that cooked fish will develop a slimy outer coat as it goes bad. However, this does not happen. It is only raw fish that will develop a slimy outer coat as it turns, so it is unlikely that you will be able to tell that the cooked fish has turned by feeling it.

But you can use another one of your senses to tell if your fish has turned, and that is by smelling it. We have mentioned that all fish generally smells bad, but you will be able to tell the difference between the normal fish smell and the stench of fish that has gone bad.

As the fish continues to go off, the fish smell will become more pungent and this will continue to grow stronger the longer the fish is allowed to turn. So once you determine that the fish has started to smell bad, you should throw it away as it is no longer safe to eat. 


In short, there are a few different ways that you can use to tell if your cooked fish has gone bad.

However, the most effective way is to smell it as it is easy to determine when the natural ‘fishy’ smell has turned into something a lot more unpleasant. 

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