It’s easy to throw some food on the counter after getting back from the grocery store, telling yourself you’ll put it away, only to get distracted and forget for a while. But when it comes to perishable foods like tuna, the timeline is a bit more strict. So, how long can tuna be left out?
According to the USDA and FDA, tuna, and all seafood, shouldn’t be left out at room temperature for more than 2 hours. This applies to both fresh and opened canned tuna. This is due to the fact that fish will face rampant bacterial growth in warmer temperatures.
There are two key types of tuna that we’ll discuss in this article: canned tuna and fresh tuna.
Canned tuna is less expensive than fresh tuna and much easier to use as it’s already cooked. Whereas fresh tuna has a higher price tag and needs cooking (most of the time, as it can be eaten raw in dishes like sushi). We’ll dive into both in this article in order to share information that will keep you safe!
We cover the following items in this post:
- The Results of Leaving Tuna in Room Temperature
- How to Store Tuna Properly
- How to Tell if Tuna Has Gone Bad
- Does It Matter if It’s Cooked Tuna or Raw Tuna?
- Final Thoughts on the Shelf Life of Tuna
The Results of Leaving Tuna in Room Temperature
Leaving tuna — fresh or canned — at room temperature (between 40 and 140 degrees Fahrenheit) can lead to the overgrowth of unhealthy bacteria, which may lead to food poisoning.
If you’re in a hotter climate then over an hour at 90°F will cause the growth of bad bacteria. If consumed, this bacteria growth can lead to food poisoning, which comes with some unpleasant symptoms. These symptoms include an upset stomach, diarrhea, nausea, cramps, a fever, and vomiting.
If you’re unable to keep the fish refrigerated, then there are a few alternative options.
- You can serve the tuna on a tray with ice. This will keep the temperature cooler and prevent the overgrowth of bacteria.
- For transportation, you can pack the food into a cool bag with ice. This is a handy tip for the summer months when transporting food back from the supermarket.
Remember that the warmer the temperature, the higher chance of food spoilage.
How to Store Tuna Properly
Food safety is highly dependent upon storing tuna correctly. Once the tuna is opened, you have a few options on how to store it.
- You can refrigerate it. This is ideal if you’ll be eating the fish within 3-5 days.
- You can freeze it for future use. This is ideal if you know you won’t get to the tuna within a few days, but want to store it for a future meal.
We go into more detail on both options below, in addition to the recommended supplies to maintain the food quality.
Pro Tip: If you’re unsure of when you plan on eating the tuna, it’s always better to freeze it rather than put it in the fridge.
Tuna can be refrigerated for 3-5 days in an airtight container or covered in plastic wrap.
- My favorite airtight container is a glass container. They’re easy to clean, don’t retain any smell, and do a good job preserving food.
- Plastic containers work well too.
- An aluminum foil cover can work as well, but the seal isn’t as tight as the other options we’ve mentioned. Do your best to wrap the container tightly with the foil.
Pro tip: For those who may use casserole dishes at times for storage, I sometimes place a tight layer of plastic wrap over the food, and then the casserole cover on top of that. It provides a little more assurance.
Tuna can be frozen in its raw state, within a meal, or from a can. Note that you can’t freeze canned tuna in a can, it must be transferred to a plastic container.
I’d recommend freezing fresh tuna in individual portions, so you can defrost exactly what you need. Although you can safely refreeze fish, there is always a risk of losing quality when doing so.
Use a freezer bag, and do your best to squeeze out as much air as possible, as this helps with limiting freezer burn. Ensure the fish is sealed in the bag tightly.
When freezing anything it’s best to ensure it’s placed into something clean and then frozen in a clean freezer. If the freezer is dirty, then there’s the risk of bad bacteria being transferred onto the fish which can then multiply during the thawing process.
And finally, don’t forget to label it with the name and date. Tuna should only be frozen for up to 3 months.
How do you Defrost Tuna?
To defrost the tuna, remove it from the freezer and place it in the fridge to thaw. This will typically take a couple of hours for a small portion, but longer for larger portions. These times also depend on your fridge temperature. Make sure it’s thawed through before cooking.
We recommend putting it in the fridge the night before you need it to ensure it thaws properly.
Some additional tips:
- Don’t microwave the tuna to thaw it faster. This can unevenly cook the fish and degrade its texture.
- Don’t leave the fish out at room temperature — even though it’s frozen. I know we covered this earlier, but some people assume because the fish is frozen, bacteria may not grow on it. That is a bad assumption, and you should always avoid this method.
How to Tell if Tuna Has Gone Bad
The easiest way to tell if tuna has gone bad is through the smell. If there is a bad fishy or sour odor, then that’s a sign that the fish isn’t fresh.
There are a couple of other things to look out for with fresh tuna:
- The tuna flesh should be red and spring back when pressed.
- There should be no discolored parts, darkening, or drying around the edges.
An opened can of tuna is on the clock as soon as you remove the cover. You can tell the fish in a can of tuna has gone bad if:
- The expiration date has passed
- The tuna smells extra fishy
- The can is damaged and possibly leaking
- The fish has spots or discoloration
On the other hand, unopened cans of tuna should generally be safe to eat as long as the expiration date hasn’t passed. They can be left at room temperature as long as they’re sealed.
Don’t take any risks with tuna if you’re unsure of its quality. As we noted above, you can get some tough foodborne illnesses from spoiled tuna, like salmonella. Always err on the side of caution and opt to trash tuna you’re unsure about.
Does It Matter if It’s Cooked Tuna or Raw Tuna?
Once the can is open, the answer is no. Both are to be treated as highly perishable options that can make you sick if safe food storage practices aren’t followed.
Final Thoughts on the Shelf Life of Tuna
Perishable foods like tuna can quickly reach a “danger zone” if left out for more than 2 hours. If consumed after that window, they can leave you very sick and create a negative association with the food.
Tuna is too good to let that happen. So, do your best to properly store tuna depending on when you need it, and be vigilant whenever you have seafood out at room temperature.
We’ve put together some helpful tips on what to do if you’ve eaten spoiled seafood in case you find that helpful!
Frequently Asked Questions (FAQs)
How Long Can a Tuna Sandwich Be Left Out?
A tuna fish sandwich shouldn’t be left out for more than two hours. This is due to the risk of bacteria growth when left at room temperature for too long.
How Long Can Tuna Salad Be Left Out?
You shouldn’t leave tuna salad unrefrigerated for more than two hours. You’ll know the tuna salad is bad if it smells unpleasant, or if it has changed colors or grown mold. Unexpected spots are always a bad sign.
Does Canned Tuna go Bad?
Yes, it does. Once opened, it should be treated the same as any other type of tuna and stored appropriately.
Can You Freeze Tuna Mayo? (Tuna mixed with Mayonnaise)
Mayo doesn’t freeze well, so this dish won’t freeze well. It’s better to freeze the tuna separately, thaw it, and then add the mayo.