You spoon half a can of diced tomatoes into dinner and pause with the rest in your hand. Do you need to find a storage container, or can you cover the can and put it in the refrigerator?
Yes. The USDA says you can refrigerate unused food in the original can. Transferring it to a clean, covered glass or food-grade plastic container is usually the better choice for flavor and convenience. What matters most for safety is getting the food cold promptly and using it within the recommended time.
If you already put half a can of beans in the refrigerator last night, you don’t have to throw them out simply because they’re still in the can. Check when you opened it and how long it sat out. You can transfer the beans now if you like, but changing containers won’t give them extra days.
What changes when you open the can?
An unopened, shelf-stable can is a sealed package designed for pantry storage. Once you open it, that seal is gone. The food can come into contact with your hands, utensils, and kitchen surfaces. A lid or wrap can protect it in the refrigerator, but it can’t turn the opened can back into a shelf-stable package.
That’s why putting the rest of the can back in the cupboard is the mistake to avoid. The same food that could sit unopened on a shelf now needs refrigeration. This applies to the tomatoes you’ll use tomorrow, the chickpeas you opened for a salad, and the peaches you plan to have with breakfast.
Some cans need refrigeration even before opening. Certain canned hams and seafood products carry a “Keep Refrigerated” label. Follow those instructions from the time you bring the product home. A metal can by itself doesn’t tell you whether the food belongs in the pantry.
Why transferring the food is often worth it
A container with a fitted lid is easier to close than a can with a partly detached metal top. It’s also easier to label, easier to scoop from, and less likely to spill when someone reaches past it. If the food came in a small can, a short container may make it easier to use the last spoonful without reaching near a sharp rim.
There’s a quality reason, too. The USDA recommends glass or food-grade plastic to help preserve flavor. Acidic foods such as tomatoes and pineapple can interact with the metal in a can and discolor or corrode its lining. You don’t need to figure out what lining your particular can has: if you have a clean container handy, transferring the food is a straightforward choice.
Glass and food-grade plastic both work. Use the one that fits the amount you’re saving and has a lid you can close securely. A small jar might be handy for a few tablespoons of tomato paste; a wider container might be easier for half a can of beans. The container doesn’t need to be fancy, and transferring the food doesn’t extend its refrigerator life.
How long do opened canned foods keep?
The USDA gives different refrigerator windows for common low-acid and high-acid canned foods. These are storage categories, not a test you can perform by tasting the food. Keep your refrigerator at 40°F or below, and follow the product label if it gives a shorter time or special instructions.
| What you opened | Examples | General USDA refrigerator guidance after opening |
|---|---|---|
| Low-acid canned foods | Beans, corn, peas, tuna, canned chicken, gravy, and many soups or stews | 3 to 4 days |
| High-acid canned foods | Plain canned tomato products, canned fruit and juice, pickles, and sauerkraut | 5 to 7 days |
You may also see a USDA answer that says to use opened canned food within four days. That’s a simple, conservative rule if you don’t want to sort foods by category. The USDA’s more detailed storage guidance gives the longer window for high-acid products. If you’re unsure which category applies, stick with the shorter window or check the label. A stew that contains tomatoes, for example, shouldn’t automatically get the same storage time as a can of plain diced tomatoes.
Count from the day you opened the can. The printed date on the package isn’t a timer for the food after opening. And if you opened the beans on Monday and moved them to a glass container on Wednesday, Monday is still the date to write on the lid.
The table is for ordinary opened canned foods. Products with their own handling directions, such as infant formula, need to be stored according to those directions.
The easiest way to save the unused half
Put the portion you’re saving away while you’re preparing the meal. That’s easier than trying to remember, after dinner, whether you opened the can an hour ago or much earlier.
- Take out what you need with a clean utensil. If you taste the food as you cook, use a separate spoon for tasting.
- Cover the unused portion. Transfer it to a clean container with a lid, or cover the original can securely if you’re keeping it there. Handle the cut edge carefully.
- Mark the opening date. A piece of tape with “black beans — Monday” is more useful than trying to recognize the contents later.
- Refrigerate it promptly. For perishables, the limit is two hours out of refrigeration, or one hour when the air temperature is above 90°F. Don’t use that time as a reason to leave the food out.
If you’re saving the dish you cooked, rather than the unused portion from the can, use the cooked-leftover guidance. For example, plain canned tomatoes may fall in the longer storage category, but the pot of chili you made with them is a cooked leftover. Divide a large batch into shallow containers, refrigerate promptly, and use it within three to four days or freeze it.
Should you keep the liquid?
That depends on what you want to make next. If the recipe called for drained chickpeas and you already drained the whole can, store the remaining chickpeas in a covered container. If you’re saving diced tomatoes for soup, keeping the juice gives you the option to use it. Peaches can stay with their juice or syrup if that’s how you like to serve them.
The key is that draining doesn’t make the food shelf-stable, and leaving it submerged doesn’t give it extra refrigerator days. Store the food promptly either way. For products with specific directions about storage in their original liquid, follow the label.
Freeze what you won’t use soon
If you open a can of tomato paste for one tablespoon and don’t have a plan for the rest, the freezer may be more useful than the refrigerator. Transfer the extra to a freezer-safe container and divide it into amounts you’ll actually use. A few small portions let you take out enough for one recipe without thawing the whole batch. The same idea works for beans you plan to add to soup or chili.
Label the portions with the food and date, and keep the freezer at 0°F or below. Freeze the food while it’s still within its refrigerator window and has been handled safely. Freezing can save food you aren’t ready to use; it can’t make food safe again after it sat out too long. Expect some foods to soften or otherwise change texture after thawing. If texture matters for a salad or snack, you may prefer to use the refrigerated portion first.
When the can itself is a reason to discard the food
An ordinary can you opened for dinner is different from a can that was bulging, leaking, or badly dented before you opened it. Don’t use food from those containers. Also discard the contents if liquid spurts out on opening or the food looks or smells spoiled. Transferring suspicious food to glass won’t make it safe.
A normal smell isn’t proof of safety, either. That matters if you can’t remember when the can was opened, or if you find it on the counter the next morning. Don’t taste questionable food to decide whether to keep it. Make the decision based on the condition of the can and what you know about the food’s storage. If it exceeded the time limit, throw it away.
These storage tips are for commercially canned food. If you’re opening a jar of home-canned vegetables or another home-preserved food, the way it was canned matters too. Refrigeration after opening doesn’t correct an unsafe canning process.
Three everyday examples
Half a can of tuna after lunch. Put the unused tuna in a small covered container, date it, and refrigerate it promptly. Plan to use it within three to four days. If you leave it in the covered can instead, the storage window is the same. What you want to avoid is forgetting it on the counter while you finish lunch and move on to something else.
Half a can of plain crushed tomatoes after making sauce. Keep the unused tomatoes separate from the cooked sauce and mark the date you opened them. Plain canned tomato products fall in the USDA’s high-acid category, with a general window of five to seven days. If the label calls for less time, use the shorter limit. If you rarely cook with tomatoes twice in a week, freezing the unused portion may fit your routine better.
A can of corn you opened yesterday and refrigerated in the can. If you chilled it promptly and kept it cold, the can isn’t a reason to discard it. Put it in a covered container today if that makes it easier to use. Keep yesterday’s date on the label. If you discover it was left out overnight instead, discard it, even if you had already transferred it to glass.
The next time you use half a can, cover the rest, refrigerate it promptly, and mark the opening date. The original can is acceptable for short refrigerated storage. A clean container with a fitted lid makes the food easier to protect, label, and use.
For more practical kitchen advice, see whether steaming food really needs to cool completely before refrigerating. And for other everyday mysteries, check out a UV test of handwashing methods and the three kinds of haze that can cloud your glasses.
