You’ve just unearthed a long-forgotten box of spaghetti from the back of your pantry that looks normal, smells normal, and has no sign of mold. According to the “use by” date, however, it expired three weeks ago. Worried that the pasta is harboring some invisible but hazardous bacteria, you mutter “Better safe than sorry,” and chuck it in the garbage can.
Similar scenes play out all over the nation on a daily basis, as we try our best to decipher the safety messages printed on food products. Part of the reason we end up trashing so much perfectly edible food is because we misinterpret what those dates actually mean. The “sell by” date, for one, is listed so retailers know how long they can keep a product on their shelves while it’s still top-notch quality. Robert Brackett, a food science expert and member of the Institute of Food Technologists, tells Mental Floss that choosing a package with the latest “sell by” date can help you ensure that you’re getting the freshest version available, but you definitely don’t have to throw it out right after that date. And though the “best if used by” date is for consumers, it’s also mainly about the quality. “The quality will be best if used by the date,” Brackett explains, “but will probably be acceptable for some time after.”
The “use by” date is slightly more direct. According to Brackett, the manufacturer “may not guarantee quality or freshness afterward,” and “nutrients listed on the Nutrition Facts panel may not be accurate after the ‘use by’ date due to natural degradation.” But even if a certain food has lost freshness and/or nutritional value after its “use by” date, that doesn’t necessarily mean it will make you sick. It might even taste completely fine, too.
Unfortunately, there aren’t exactly hard-and-fast rules for how long foods can safely be eaten after their so-called expiration dates. That said, plenty of products don’t have to be tossed as soon as the “use by” date is a red X on your desk calendar. “A good rule of thumb is: The more perishable the food is, the sooner after the date that it should be used,” Brackett says. “For example, one may be able to consume cereal for a month after the date, whereas milk will need to be consumed within a week or two.” In general, your senses can often help you decide. If the sight, smell, texture, or taste of something doesn’t seem right, go ahead and throw it away without feeling guilty.
Below are some guidelines from Brackett for 10 types of food you can safely feast on after their “Use by” dates.
Refrigerated eggs are safe to eat after the expiration date, and bad ones usually emit a rotten odor, even when cooked. Deciding when to trash them partially depends on what you’re planning to use them for. “The functional quality of eggs (such as whipability, etc.) diminishes as the eggs get older,” Brackett says.
Like eggs, milk is also safe to consume past its “use by” date as long as it’s been refrigerated. Brackett says (harmless) microorganisms might make it sour or bitter, so trust your senses.
4. Hard Cheese
According to Brackett, the ripening process for a hard cheese—“especially a hard grating cheese such as Parmesan”—can keep going for years after its expiration date. You can still eat it, but the texture and flavor will change as it ages.
If your yogurt doesn’t taste unusually sour and it doesn’t have any mold on it, it should be safe after its “use by” date.
6. Dried Pasta
Pasta could potentially last years as long as it’s kept dry, while exposure to moisture can cause mold to grow. Even if it’s still technically safe to eat, the flavor and odor will eventually diminish enough that you probably won’t want to.
7. Canned Goods
Canned goods can also last for years, and the expiration dates are mainly so you know when the flavor and nutritional quality will start to decline. If the can is swollen, however, you should throw it out—that can indicate spoilage.
8. Frozen Food
The key here is to keep foods “continuously frozen.” If your freezer breaks or your power goes out, for example, frozen foods can thaw and start to spoil before they get re-frozen. But even if a product has been kept frozen, freezer burn—which is essentially dehydration—or rancidity can diminish flavor and make you decide to throw it out anyway.
If you ever managed to make your Halloween candy last until next year’s haul, you might already know that old chocolate isn’t quite as tasty—but it isn’t harmful. The white, powdery film you sometimes see on a piece of chocolate is safe to eat, too. It’s either “sugar bloom,” which happens when the sugar absorbs excess moisture, or “fat bloom,” which occurs when the fat collects on the surface.
10. Dried Herbs and Spices
You don’t have to throw out your oregano flakes as soon as they expire, but they will eventually—as you can probably guess—lose their seasoning potency after a while.