A can of beans that rolled to the back of the pantry shelf tends to resurface at the worst time, usually when a recipe is half started. Four problems decide whether that can goes into the pot or into the trash.
Ohio State University Extension lists four can problems that call for tossing the can: bulging, dents on the side seam or rim seams, leaking, and rust. The advice comes from a pantry clean-out column by Melinda Hill, an OSU Extension family and consumer sciences educator in Wayne County, dated April 19, 2016. Other extension services have repeated the same warnings since.
Bulging Lids Mean the Food Is Spoiled
The first problem is the easiest to see. According to OSU Extension’s Wayne County column, “If cans are bulging, the food inside is spoiled and they should be discarded.”
A swollen can does not need a taste test or a second opinion. Clemson University’s Home and Garden Information Center calls a bulging lid or a leaking can a sign of spoilage in its factsheet on handling canned goods, which was updated June 12, 2024. It adds that spoiled food should be discarded without tasting.
The same advice applies to a can that spurts liquid when it is opened or smells wrong. Pantry staples have changed over the decades, as a list of foods from the ’60s that boomers loved shows, but a swollen can has never been one worth keeping. Anyone who keeps a stock of canned goods may also find a few best practices for seasonal storage useful when the pantry is overflowing.
Seam Dents Let Air In
The second problem is the one most shoppers misjudge. OSU Extension says cans with dents in the side seam or the rim seams should be discarded, because a dent there can let in air and harmful bacteria.
Not every dent is a problem. The University of Nebraska-Lincoln’s food safety FAQ, reviewed and updated in 2022, says a small dent on an otherwise sound can is fine, but it tells readers to discard any can with a deep dent, meaning one a finger can lie in, and any can with a deep dent on a seam.
The two sources point the same way. A shallow dent in the middle of the can is a cosmetic issue, while a dent along a seam is a reason to toss it.
Seam dents are easy to miss in a crowded cabinet. A set of clever storage hacks to maximize every inch of space can give cans enough room to be turned and checked, and a list of things that do not belong on a kitchen counter is a good prompt to keep spare cans in the pantry, not by the stove.
Leaking Cans Do Not Belong in the Pantry
The third problem is a can that leaks. OSU’s column says to discard cans that leak, and Washington State University’s Food Safety in a Minute series says the same in episode 058, where the guidance reads, “Discard cans which are bulging, rusted, leaking, or badly dented.” The WSU page carries no publication date.
A leak means the seal has failed or the can has been damaged, and a sticky ring on a shelf is often the first clue.
The kitchen has other trouble spots. A list of things never to store under the kitchen sink is a reminder that moisture and cans do not mix.
Rust Is the Fourth Warning
The fourth problem is rust. OSU Extension says not to use food from rusty cans, and Clemson notes that rust may cause leaks and spoilage, which is why it says to keep cans dry.
UNL draws a useful line here. It says to discard heavily rusted cans, which can have tiny holes that let bacteria in, while surface rust that rubs off with a finger or a paper towel is not serious. If there is rust on the inside of an opened can, UNL says not to eat the food.
The four problems add up to a simple pantry routine: look at the lid, the seams, the sides and the bottom before opening any can. A can that fails any one of the four goes in the trash.
Where the Shelf Sits Matters Too
Heat makes things worse. OSU says storage above 70 degrees F shortens shelf life and cans should never be kept above 95 degrees F, such as in a shed or garage. Clemson puts the best range at 50 to 70 degrees F and says storage time drops sharply above 75 degrees F.
Clemson also gives shelf-life ranges for unopened cans in a cool, dry pantry: 12 to 18 months for high-acid foods such as tomatoes and juices, and 2 to 5 years for low-acid foods such as meat, poultry, beans and corn.
The tin can has a long history. According to Wikipedia’s entry on canning, Frenchman Nicolas Appert began sealing food in glass jars around 1809, Peter Durand patented the tin can idea in 1810, and the 1860s brought machine-made steel cans that cut cooking time from about six hours to roughly thirty minutes.
The cans in a modern pantry are descendants of those early designs, and they can sit there for years. One thing has not changed since then: a can that bulges, has a seam dent, leaks or rusts is not worth keeping.
The OSU column is from 2016 and the WSU episode is undated, but the guidance has stayed consistent across sources that were updated as recently as 2022 and 2024.
This article was produced with AI assistance and edited for accuracy against the sources linked above.
Image: Sun Ladder – CC BY-SA 3.0/Wikimedia Commons
