How to know if tuna is spoiled

In this brief article, we will be having a look at some ways to tell spoiled tuna from tuna that is fresh and edible. We will also touch on some dangers of consuming spoiled tuna, as well as a few ways to handle and store tuna for the longest possible shelf life.

How to know if tuna is spoiled?

You will know when tuna is spoiled if you see any discoloration of brown, black, or even green in some cases can clue you in towards it being spoiled. When canned, tuna can have a shelf life of up to three years. 

Signs that tuna is spoiled 

Tuna is a widely popular seafood, being used in a variety of dishes such as salads and sandwiches, as well as being eaten cooked. Here are a few ways to tell when it is safe for consumption.

  1. Color

Fresh tuna is pink, bright red, or light brown in color. If it appears dark brown, black, or even green, it has gone bad and is not fit for consumption anymore. Check the flesh close to the bone for an accurate assessment of its viability.

  1. Smell

Even though tuna has a strong “fishy” scent, it is more of a meaty, saltwater-like scent. If your tuna smells foul and overpowering and makes you lose your appetite, it’s likely to have gone bad and should be thrown out immediately.

  1. Expiration date

Check the bag or can your tuna come in. There should be a label on there telling you how much longer you can keep your tuna in the form of a “best by” or “use before” date. If the date has passed, get rid of the fish.

  1. Condition of the bag/can

Check the can or the bag your fish came in before you open it. If it seems torn, bent, rusted, punctured, dented, or otherwise damaged, the fish inside is compromised and might already have gone bad. Use your other senses to decide if it has rotten or gone bad.

  1. Taste

If all else fails, try taking a small bite out of your tuna. If the taste feels off, do not consume that tuna, and immediately throw it out. This method is not recommended as it can expose you to spoiled tuna.

How to store your tuna for the best possible shelf life

Tuna can go bad very quickly if improperly stored, so it is important to handle and store it with care and under hygienic conditions. Here are a few ways for you to extend the shelf life of your tuna.

  1. Refrigerating

Tuna can last for up to five days in the fridge at the longest. To properly refrigerate, place in an airtight container at a relatively cold temperature. Having an airtight container is also important since the strong scent of tuna can linger on other items inside your fridge.

  1. Freezing

When frozen, freshly caught tuna can last up to two weeks. When freezing, it is best to place it inside a vacuum-sealed freezer bag to retain the greatest amount of flavor and freshness possible. Moreover, only thaw what you are immediately going to use since you will only have a few hours after you thaw the fish before it goes bad.

  1. Canning

Canned tuna is the most durable way of storing tuna since this method takes most of the moisture out of the fish, making it shelf-stable. Tuna can last for up to three years when canned.

Just make sure that you store your canned tuna in a cool, dark, and dry place, and elevated from the floor to best protect it from microbes. Keep an eye out for dents, dings, or rust on the cans since these can puncture the seal, making your tuna go bad a lot sooner than it would otherwise. The easiest place for this type of storage is your pantry.

Dangers of consuming spoiled tuna

When spoiled, tuna can be dangerous for your health as rotten tuna can harbor bacteria such as Salmonella which can lead to diarrhea, vomiting, nausea, and abdominal pain and cramps. In extreme cases, you can even get botulism from consuming raw tuna, so it’s best to throw it out when in doubt.

Therefore, always check the expiration date before you buy, and always inspect your tuna before use to avoid any risks to your well-being. 

Other FAQs about Tuna that you may be interested in.

How many times a week can you eat tuna?

What is the difference between albacore and yellowfin tuna?

How much tuna is safe for cats?


In this brief article, we have had a look at some ways to tell spoiled tuna from tuna that is fresh and edible. We have also touched on some dangers of consuming spoiled tuna, as well as a few ways to handle and store tuna for the longest possible shelf life.