But while you’re opening it, you see
the date stamped on the top and recoil. The soup expired two months ago! Or did it? When it comes to canned
foods — and a lot of foods in general — it turns out many
consumers aren’t always sure what those stamped dates actually mean.

Sell by dates and best by dates are
not actually mandated by the Food and Drug Administration (FDA). Unless it’s
for infant formula, the dates on packages are voluntarily provided by the
manufacturers. Stores can even sell products that are weeks or months “past”
their dates.

So, what do the numbers on the cans
really mean? TODAY Food reached out to the Canned Food Alliance, whose
spokesperson pointed us to their basic guide referencing expiration dates. According to their
guidelines, canned food (when kept at relatively stable temperatures) will remain
at peak quality for at least two years after it’s been processed. They note
that while food in cans “retains its safety and nutritional value well
beyond two years,” its color and texture may change after that time. Many
factors affect how long a food will stay edible in the can, but food kept at
“moderate temperatures [75 degrees or below]” may last indefinitely.

Does that mean you should be eating
food out of a can found on the Titanic? Probably not.

Ron Giles, Quality Assurance Director
of Goya Foods, Inc. says
the canned food industry prefers to use “best by” dates as opposed to
expiration dates.

“Canned foods do not expire on a
certain date,” explains Giles. “One cannot say that the canned food is good on
one day and not good the next day. Canned foods are under a vacuum. The absence
of oxygen helps to extend the shelf life of canned foods.”

A “best by” date, on the
other hand, indicates when a consumer may notice a decrease in quality. For
example, the food’s color, texture or flavor may not be optimal. NBC nutrition
consultant and registered dietician Bonnie Taub-Dix, author of “Read It Before
You Eat It
,” said that there may also be a decrease in
nutritional value.

But even then, it takes years for
that to happen. Goya canned beans, for example, have a best by date of three to
five years from the day of production. Goya — which is one of the world’s
largest food processing companies — determines a product’s shelf life by taking into account several
factors. In addition to looking at industry standards and doing internal
evaluations, the company uses insight from packaging material suppliers.

So which older canned food is safer
to eat? In general, foods that are more acidic will actually expire sooner.
Foods with a more basic pH level will last longer than most canned vegetables
and fruits. This means good old Spam may actually outlive those canned peaches.

But storage quality is really the
biggest determinant of canned food safety.

“When I think ‘zombie apocalypse
bunker’ I think canned food!” says Emily Peterson, Chef Instructor at the Institute of Culinary Education.
“Can something meant to feed us ‘forever’ in case of emergency ever really
expire?” Peterson doesn’t tell her culinary students to focus on the dates on

“I’m more concerned about the state
of the can itself. Is it swollen? That’s a definite no-go. Is it dented or
rusted? Throw it away.”

The problem with cans that are in less-than-perfect condition
(think dents, dings and swollen areas) is that the hermetic seal and protective
lining inside can be broken. Cans are coated with an interior lining that
prevents the can’s metal from coming in direct contact with its contents. If
the outside of the can is dented, there’s a good chance the interior lining is
compromised as well.

Usually, this results in the can
rusting or swelling up as the food reacts with the steel, tin or aluminum in
the can. Bacteria can also grow and release gases that make the can bulge.
(Botulism is a concern for goods improperly canned at home, but it’s not a concern
for commercially canned food.)

If the can looks fine but you’re
still uncomfortable with it being past the best by date, donate it to a food
pantry. Many food pantries accept, or will properly dispose of, expired goods.
To avoid getting into a tricky situation in the first place, implement the
first in, first out rule. “When storing your canned goods, newer items should
go towards the back while older items should be towards the front of cabinets
or pantries for easier access,” says Mandy Enright, a registered dietician based in New Jersey.

If the can looks fine and you want to
go for it, no problem. Just get a good whiff first. If something doesn’t smell
right and it doesn’t look right, don’t eat it or serve it.

“Remember that even without a
pickup line, every food in the supermarket gets a date,” says Taub-Dix.
“These dates help consumers choose the freshest and safest foods
available. The bottom line, though, is … when in doubt, throw it out!”