9 Ways to Tell if Your Canned Tuna Is Bad

Canned goods fill our pantries for easy, reserve meals. You never know when you might be stuck at home for an extended period and need to be able to prepare meals. Or maybe you’re just a planner and like to keep your canned goods well stocked for meals and everyday use.

Whatever the thought process is behind your pantry, chances are you have various types of canned goods. Tuna is a very popular canned product because it is cheap and can be used for many different things. It is easy to work with and lasts quite a while in the can.

Canned goods often have “use by” dates, but how can you really tell if your canned tuna has gone bad or not? Interestingly, there are several tips and tricks that can help you tell if your canned tuna has gone bad. The main ways to tell if your canned tuna has gone bad are to check the expiration date, see if the can is leaking, smell it for bad odors, see if it has changed color, check the can for damage, and, Finally, try it, which should be your last option if you have suspicions.

In this guide, we’re going to cover 9 very basic tips so you can understand when it’s time to throw that tuna in. These tips have simple guidelines that will help you determine if your canned tuna is safe to eat.

Read on for the best ways to tell if your canned tuna is good or bad.

Canned tuna: how to know if it is good or bad

Canned tuna is incredibly versatile. We buy it because we like the taste of tuna and because it costs very little to stock our pantries and cupboards with it. You can do a lot of different things with tuna, and being a canned product, it stays fresh for quite a while.

The good thing about canned products is that they tend to last much longer than the fresh version of the food. With proper storage methods, canned tuna will most likely keep on the shelf for 3-5 years, which is an incredible length of time.

Canned tuna usually has an expiration date.  All canned goods must have a date stamp. What you need to understand is that these dates are really “use by” dates, which means they cannot guarantee quality after that date.

Proper storage is key, but it won’t necessarily go bad if you have it stored past that date. We are going to talk about 9 ways to try to determine if your canned tuna is bad.

1. Check the dates

Normally, canned products can be consumed after the expiration date. This date is there to guarantee quality over time. Clearly, the longer tuna is stored, the more it risks losing its essential quality.

We have already said that tuna can generally be eaten after the date, but we want you to be aware of it. We recommend that you mark the date you bought the tuna as a good measure of how long you have stored it on your pantry shelves. 

This is the starting point. If you’re at all worried about your tuna going bad, you can check the date and use this tip in coordination with some of our other tips to really figure out whether or not to throw it out.

2. Leaky Can

If the can is leaking in any way, don’t eat the tuna. Can leaks don’t happen very often, but it is possible.

If your canned tuna is leaking, it means that something has gone wrong in the preservation process and it is no longer preserved in the can it is in. If it leaks, don’t eat it, regardless of the date stamp and other factors. 

The purpose of canned goods for preservation is that everything is pressure sealed inside the can. If something leaks, the internals of the can are not guaranteed to be properly preserved.

A leaky can means that you should not even consider the meat, but throw it away. 

3. Smells speak

Canned goods don’t always smell good when you open the can. That’s because what’s in that tin has been locked in there with some oil or water to preserve it for a long time.

However, tuna is a form of fish and therefore has a fishy smell. If you’ve eaten a lot of canned tuna, you’re probably somewhat familiar with the smell it usually gives off when you open the can.

A good way to tell if your tuna is bad is to smell it good. You will most likely notice an unpleasant odor as soon as you open the can. It won’t smell fishy, but rather pungent or even slightly sour, rather than tinned fish.

If you notice a pungent or rotten smell, we recommend throwing it away and washing your hands to make sure you haven’t gotten any of that liquid on yourself. 

4. Green, black, brown = bad

This is an obvious way to tell if your food has gone bad.

Tuna that has gone bad often has dark brown streaks, streaks that can even appear black. These streaks will be an obvious discoloration running through the meat and you should definitely not try to eat it.

Sometimes the tuna can also turn green, which is another sign that the tuna has gone bad. If your tuna has any of these discolorations, it is not safe to eat.

5. Look for the color pink

This tip goes hand in hand with tip 4. Tuna meat coloring ranges from light pink to bright red. Bright red can even have a slight brownish tint.

So how can you tell if it’s a good brown or a bad brown? Bad tuna will be an obvious, very dark brown color, potentially close to black. Good tuna, even if dark in color, will still have more of a reddish hue. You will know the difference. 

6. Exploding cans

The can probably won’t explode when in the cabinet (although it is possible). However, if you open the can and things explode or are projected out of the can, that’s a sign that something was wrong. Sometimes the can may even be bulged.

You may hear a popping noise or food come out quickly when you open the can; in any case, it is not a good sign for the tuna. 

Clean up the clutter and throw it all away. The tuna is bad, something in the canning process was not effective.

7. Corrosion on the can

If you notice corrosion or rust on the can, it’s probably better to be safe than sorry. Corrosion can cause puncture-sized holes to appear on the surface of your can. These holes are relatively small and you may not even be able to see them.

It is better not to risk it. If you notice that your tuna can is showing signs of corrosion, it means that air and possibly even moisture can get to the food in the can and you should throw it away. 

8. Dented and damaged cans

We’re not saying you can’t eat food that’s in a dented can. Many grocery stores reduce the cost of damaged cans because the expiration date could be negatively affected by the damage.

A dent, specifically a dent in the lid of the can, could mean that the can’s pressurization has been released and you don’t even know it . In this case, bacteria can build up in the food, causing salmonella and other nasty things you don’t want to eat.

If you notice a dent in the top of the can, we recommend that you throw it away. 

9. Take a sample

If all else fails and nothing seems out of the ordinary about your tuna, take a small bite. If the tuna doesn’t taste good or tastes weird, we wouldn’t risk it. 

When it comes to food, especially canned food, it’s better to throw it away than risk getting very sick. Tuna is cheap and it is not worth risking your health just to save a can of tuna.

Related questions

We hope you find this guide on the 9 best ways to tell if canned tuna is bad for you a useful resource in understanding whether or not you should eat that tuna.

We invite you to take a look at the following question and answer section for additional information that may be valuable to you.

How is canned tuna stored correctly?

The best way to store any canned product is out of direct sunlight and heat. Store canned tuna in cool, dry places. Pantries or cabinets with closing doors are the best storage places for canned tuna and other canned goods.

Is it necessary to refrigerate canned tuna?

It is not necessary to store canned tuna in the refrigerator until after opening the can. Canned goods usually do not need refrigeration when unopened.

However, once the tuna can is opened, the tuna remains should be stored in the refrigerator or thrown away.