Most of us have less-than-perfect habits when it comes to storing food — especially when it comes to canned foods. After all, it's easy to toss a can of chickpeas into the refrigerator with some plastic wrap over it until you decide you want to use the rest.
But after years of hearing that refrigerating food in cans isn't a best practice, it's time to find out if doing so is safe once and for all.
Can You Store Food in Open Tin Cans?
According to the USDA Shelf-Stable Food Safety report, it is completely safe to refrigerate unused leftover food in its can. However, both the USDA and Gitanjali Kundu, assistant professor of biology at Brookdale Community College in Lincroft, New Jersey, agree that transferring the leftover food to a glass or plastic storage container can help preserve the food's quality and flavor.
Since exposing the food to oxygen also exposes it to bacteria and microorganisms in the air, Kundu recommends always sealing your containers. If you don't, you could risk exposing your leftovers to airborne germs, some of which might make you sick, she says. "There's [also the] potential decomposition of the food, which may cause health risks."
Read more: The Danger in Eating Too Much Canned Tuna
There are also concerns about BPA in cans, she adds, which may "leach out from the aluminum and tin." BPA, a coating that lines the inside of many cans, is thought to mimic estrogen and may be linked to "cancer development and progression," according to a January 2015 study published in Medicine, although more research is needed in humans. That said, you may want to opt for canned foods that clearly state "BPA-free" when possible.
How Long Can Food Stay Fresh in a Can?
The type of food you've got in that open can can help determine how long you can leave it in the fridge. Highly concentrated canned products, like condensed milk, often stay safe to consume longer than less concentrated foods, like chicken broth, Kundu says, adding that soft canned cheeses like mozzarella will spoil more quickly than black beans, which will keep longer.
All in all, Kundu suggests avoiding putting an open can in the fridge. "You should put the food in a glass or plastic container and put a tight lid on it [to prevent] microorganisms [from] entering," Kundu advises. Consider investing in a Pyrex glass storage set. Or, if you insist on keeping your food in its can, cover it tightly when putting it in the refrigerator; these plastic can lids can help.
Is Canned Food Even Healthy?
Refrigerated or not, keep in mind canned goods often come with a serious side of salt. "Many times, canned foods contain preservatives, and some are stored in saline environments that are very salty," Kundu says, easily pushing you toward your recommended sodium intake for the day.
A quick rinse under lukewarm water can help remove some of the added salt from canned foods, Kundu says.
Of course, if something in the canning process itself unintentionally goes wrong, your food could pose a danger too. "Sometimes, bacterial cells may slowly grow if the process of canning or sterilization didn't go well," Kundu says. The Food and Drug Administration (FDA) warns to look out for damaged cans, as they can harbor contaminants such as Clostridium botulinum, which can cause botulism.