Tuna is a great source of protein, easy to prepare in a variety of ways and a good source of your daily omega-3s, so it’s not surprising that it’s in pantries everywhere.
But what to do if a can gets opened and then left out overnight? What if the fresh tuna was left in a grocery bag overnight?
Fresh or canned tuna that has been opened and left to sit out overnight should not be eaten. The USDA puts tuna solidly in the “danger zone” after two hours of sitting in room temperature environments.
How can you identify if your tuna has gone bad if it has been sitting out for just a bit? What should you be looking for? What are the risks of consuming tuna that’s gone bad? Continue reading as we’ll cover all of these topics.
How Long Can Tuna Be Left Out Before Going Bad?
Tuna comes in a few different forms so we’ll break it down here to be clear about the kind of tuna you’re wondering about. There’s fresh tuna – skipjack (most common), albacore, yellowfin, and bigeye; and there’s canned tuna–albacore and chunk light.
Canned tuna of either variety that has not been opened can sit on your pantry shelf for years and still be safe to consume.
If you’re hoping to make some tuna salad and wondering about a closed can that you found deep on the pantry shelf, chances are very good that you’ve purchased and brought it home within its safety window. Bon Appetit.
If you’ve opened the can of tuna and left it out, it’s an immediate game-changer. Canned tuna that has been opened should not be eaten if it has been sitting out of cold storage for more than two hours.
It’s worth noting here that it’s important to pay attention to your environment. If it’s a hotter-than-average day, shorten that window of time and eat the leftover tuna in under an hour or, get it into the fridge.
If tonight is homemade sushi night and you came home from the market with a fresh, sushi-grade tuna steak and forgot to put it in the fridge, proceed carefully.
The USDA gives it two hours before you should throw it away; but with raw fish, you want to be careful and shorten that window if it’s warmer than average in the area you left it sitting out.
As with most perishable foods, the general rule of thumb is to eat it immediately or get it into cold storage in under two hours. As always, err on the side of caution.
How to Tell If Tuna Has Gone Bad
The good news is that tuna will be very honest with you and let you know immediately if it should be eaten or thrown out. There are three ways to get a good sense of how safe it is to eat: check the smell, the color, and its packaging.
Because tuna is a pungent fish, the fact that it has an odor is not enough to tell you if it’s gone bad. The smell will be strong even if it’s fine to eat, but it should be a fresh and clean smell, whether it’s from the butcher or the can. If it has an unappetizing odor or makes you turn away when you smell it, it has gone bad.
When you’re buying fresh or frozen tuna, the color of the steak is something to pay attention to. The fat content in different kinds of tuna determines how red or pink the flesh is, and further processing of frozen steaks uses methods to keep the red and pink hues from turning an unappetizing shade of brown.
If you notice browning around the bone in the tuna steak, beware: that is a sign that it has not been properly stored during the transport or grocery storage process.
If there is any indication of darker brown, black or green–in fresh OR canned tuna, discard it immediately.
Finally, check the packaging for two important pieces of information to see if your tuna is bad. One, look for the sell-by date on canned or frozen tuna. If you’re within a reasonable timeframe of that date, you should be good to go.
Two, when it comes to canned tuna, look for any bulges or openings at the seams of the can itself. If you find any abnormalities on the can (other than dents from transport or falling off your pantry shelf), throw the can away, as it’s a sign that the tuna is bad and that is just not worth the risk of food poisoning.
Can Eating Bad Tuna Make You Sick?
Eating bad food of any kind can make you sick and tuna is no exception. If you know it’s been out longer than is safe or you’re taking a risk on a questionable can of tuna, you risk food poisoning.
Symptoms of food poisoning from bad fish can range from minor stomach discomfort to major cramping, diarrhea and vomiting. More extreme cases of these symptoms can lead to dehydration which is a serious health concern for which you should seek medical help.
If you’ve made a delicious tuna salad and forgot to get it into the fridge, it’s hard to resist the temptation to eat the leftovers – we get it. But given the discomfort caused by eating bad food, you’d be wise to consider the consequence and play it safe.
How Should Tuna Be Stored?
Tuna salad can make for great meals for days to come, so be sure to get it wrapped up and stored properly so you can enjoy your leftovers in sandwiches or salads!
If you’ve opened the can of tuna and mixed it with vinegar or mayonnaise and made your favorite tuna salad recipe, eat what you want, and then put the rest in a tightly sealed container or bag and refrigerate.
Tuna salad can also be frozen if you don’t think you’ll want your leftovers in the next day or two. Place it all into a resealable bag or storage container (leaving a bit of room for the freezing process to expand the food), and store it in your freezer for up to five days.
If you’re going with the freezing option, but want to make the thawing and serving step easier, pack your leftover tuna salad into individual serving sizes before you freeze. Then, just take them out as needed and enjoy them for up to five days.
If your eyes were bigger than your stomach for sushi night and you want to save the fresh, raw tuna for a salad tomorrow, be sure your refrigerator is set at 39F or lower, wrap the leftovers tightly in plastic wrap and a resealable bag or storage container and enjoy for up to two days.
Do not refreeze fresh tuna that you bought at the store as it was flash-frozen for its initial transport and you don’t want to refreeze fish. Similarly, if you thawed your tuna at home, do not refreeze. Refrigeration is the way to go if you have any leftover fresh tuna.
How Long Does Canned Tuna Last at Room Temperature?
We all love having it on hand for quick lunches, high-protein additions to salads, and kid-friendly meals, but how long can it sit on that pantry shelf and really still be okay to eat?
The canning process for tuna seals the fish off from any potential bacterial growth and creates an environment for the food that makes it safe to sit on your shelf for approximately four years. The exception, of course, is if you see any bulges or broken seams in the can; if so, throw it away.
Once you’ve opened the can, it will only be good to eat for approximately two hours when left at room temperature.
Since it’s the canning process that preserves the meat– and not any smoking or salting or otherwise preserving the actual fish itself–it will begin to grow harmful bacteria within two hours of an average temperature day.
If it’s hotter than 90F/32C, you should not keep tuna out of cold storage for more than an hour and still hope to eat it.
Whether it’s a tuna salad recipe handed down from a great-grandmother or an experiment hosting a homemade sushi dinner party, tuna can be a family and crowd pleaser. Make the most of this great food and your efforts by getting leftovers properly stored away so you can enjoy them again the next day!