I threw out a perfectly good block of cheddar last year because the “sell by” date had passed. Almost four dollars, gone—on cheese that was completely, unambiguously fine. That was my wake-up call to actually figure out what these labels mean, because clearly I’d been operating on pure guesswork.
Here’s what most people never realize: the U.S. has no federal law forcing manufacturers to put expiration dates on most foods. Baby formula’s the big exception, but everything else? Those dates are voluntary. They’re about peak quality, not safety. And that distinction matters a whole lot more than your grocery store would like you to think.
“Sell By” Is Not an Expiration Date
Full stop. It just isn’t.
“Sell by” is a message aimed at the store, not at you. It tells retailers when to rotate product off the shelf so customers get it while it’s still at peak freshness. Milk with a “sell by” date is generally safe to drink 5-7 days after that date, per the USDA. Eggs? Up to 3-5 weeks past sell by, as long as they’ve been properly refrigerated.
So when you see that date creeping up in your fridge, don’t panic. You’ve almost certainly got more runway than you think.
“Best By” Means Best Quality, Not Last Day of Safety
This is the one that trips everybody up. “Best by” (sometimes printed as “best if used by”) is simply the manufacturer’s estimate of when the product will taste, smell, or perform at its absolute peak. After that date, quality might slip a little. Safety, though? Usually not a factor at all.
A bag of tortilla chips marked “best by June 2024” eaten in July 2024 might be slightly stale. But it won’t make you sick. Canned goods are the classic example—the USDA has documented canned foods that were safe and edible literal decades past their printed dates. A 2021 Iowa State University food science study confirmed that most shelf-stable foods stay safe well beyond their “best by” windows, even if flavor and texture slowly degrade.
“Use By” Is the One You Should Actually Take Seriously
Of all three labels, “use by” carries the most weight. You’ll typically find it on perishables—deli meats, fresh juices, certain dairy products—where the manufacturer is flagging a genuine safety concern, not just a minor quality issue. Personally, I don’t push it when cold cuts have a “use by” printed on them. That one I respect.
But even here, context isn’t irrelevant. A sealed, properly refrigerated product can sometimes squeak a day past “use by” without issue. An opened package? Honor that date fully.
The Foods Where You Really Shouldn’t Gamble
Some foods warrant real caution regardless of whatever label confusion surrounds them. Raw poultry and ground beef spoil fast—both can harbor salmonella or E. coli without any obvious smell to tip you off. Fresh shellfish. Unpasteurized cheeses. These aren’t “check the date and wing it” situations.
And look, if something smells wrong, looks slimy, or has mold creeping beyond a small spot on hard cheese—trust your senses. Your nose literally evolved to detect microbial danger. It’s surprisingly good at the job.
Bottom Line
Here’s the thing nobody else seems to say out loud: the real skill isn’t memorizing which dates matter most. It’s learning to use your senses as the primary tool and treating printed dates as backup signals. Most food waste in American households (ReFED estimated $1,500 per family annually in 2021) doesn’t come from eating expired food. It comes from tossing food that was never actually dangerous. So flip your default assumption. Instead of asking “is this still okay?” start asking “is there actual evidence this has gone bad?” That one mental shift could save you hundreds of dollars a year.
Frequently Asked Questions
Can you eat yogurt past its best by date?
Yes—typically 1-3 weeks past the printed date if it’s been sealed and kept cold. Just check for mold, off smells, or separation that seems excessive.
Is expired canned food dangerous?
Rarely. Unless the can is bulging, dented along a seam, or rusted, the date is a quality marker rather than a safety cliff.
Do frozen foods actually expire?
Technically no. Frozen food stays safe indefinitely. Quality degrades somewhere between 3-12 months depending on the item, but “expired” frozen peas won’t hurt you.
Why do stores still pull products at the sell by date?
Mostly liability and customer perception. Stores aren’t legally required to yank items at sell by, but most do anyway to avoid complaints and keep shoppers from losing trust.
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