From the New York Times, January 24, 2023
The Food Expiration Dates You Should Actually Follow
The first thing you should know? The dates, as we know them, have nothing to do with safety. J. Kenji López-Alt explains.
Have you been reacquainting yourself with the forgotten spices and fusty beans from the depths of your pantry? How fusty is too fusty? When is the right time to throw something out? And what about fresh ingredients? If I’m trying to keep supermarket trips to a minimum, how long can my eggs, dairy and produce keep?
Here’s the first thing you should know: Expiration dates are not expiration dates.
Food product dating, as the U.S. Department of Agriculture calls it, is completely voluntary for all products (with the exception of baby food, more on that later). Not only that, but it has nothing to do with safety. It acts solely as the manufacturer’s best guess as to when its product will no longer be at peak quality, whatever that means. Food manufacturers also tend to be rather conservative with those dates, knowing that not all of us keep our pantries dark and open our refrigerators as minimally as necessary. (I, for one, would never leave the fridge door open for minutes at a time as I contemplate what to snack on.)
Let’s start with the things you definitely don’t have to worry about. Vinegars, honey, vanilla or other extracts, sugar, salt, corn syrup and molasses will last virtually forever with little change in quality. Regular steel-cut or rolled oats will last for a year or so before they start to go rancid, but parcooked oats (or instant oats) can last nearly forever. (Same with grits versus instant grits.)
White flour is almost certainly fine to use, no matter its age. Whole-wheat and other whole-grain flours can acquire a metallic or soapy odor within a few months. This whiter-equals-longer rule of thumb is true for nonground grains as well. Refined white rice, for example, will last for years, while brown rice will last only for months.
This is because unrefined grains contain fats, and fats are the first thing to go off when it comes to dry pantry staples. Tree nuts, typically high in fat, will go rancid within a few months in the pantry. (Store them in the freezer to extend that to a few years.)
Shelf-stable supermarket breads made with oils (and preservatives) can stay soft for weeks in the fridge, but the lean, crusty sourdough from the corner bakery will be stale by the next day and probably start to mold before the week is up. (I slice and freeze my fancy bread, taking it out a slice at a time to toast.)
Dried beans and lentils will remain safe to eat for years after purchase, but they’ll become tougher and take longer to cook as time goes on. If you aren’t sure how old your dried beans are, avoid using them in recipes that include acidic ingredients like molasses or tomatoes. Acid can drastically increase the length of time it takes beans to soften.
We all make fun of our parents for using spices that expired in the 1980s, but, other than losing potency, there’s nothing criminal in using them (unless you consider flavorless chicken paprikash a crime).
What about canned and jarred goods?
As a rule, metal lasts longer than glass, which lasts longer than plastic.
So long as there is no outward sign of spoilage (such as bulging or rust), or visible spoilage when you open it (such as cloudiness, moldiness or rotten smells), your canned fruits, vegetables and meats will remain as delicious and palatable as the day you bought them for years (or in the case of, say, Vienna sausages at least as good as they were to begin with). The little button on the top of jarred goods, which will bulge if there has been significant bacterial action inside the jar, is still the best way to tell if the contents are going to be all right to eat. Depending on storage, that could be a year or a decade. Similarly, cans of soda will keep their fizz for years, glass bottles for up to a year and plastic bottles for a few months. (Most plastics are gas-permeable.)
Oils, even rancidity-prone unrefined oils, stored in sealed cans are nearly indestructible (as evidenced by the two-gallon tin of roasted sesame oil that I’ve been working through since 2006). Oils in sealed glass bottles, less so. Oil in open containers can vary greatly in shelf life, but all will last longer if you don’t keep them near or above your stovetop, where heat can get to them.
How do you tell if your oil is good? The same way you would with most foods: Follow your nose. Old oil will start to develop metallic, soapy or in some cases — such as with canola oil — fishy smells. Don’t trust your nose? Put a drop on your fingertip and squeeze it. Rancid oil will feel tacky as opposed to slick.
Also from the oil-and-vinegar aisle: Salad dressings will last for months or over a year in the fridge, especially if they come in bottles with narrow squeeze openings (as opposed to open-mouthed jars).
Mustard lasts forever. Ketchup will start to turn color before the year is out, but will still remain palatable. Contrary to popular belief, mayonnaise has an exceptionally long shelf life, especially when it doesn’t contain ingredients like fresh lemon juice or garlic. (High concentrations of fat, salt and acid are all enemies of bacteria and mold.)
The international aisle is a den of long-lasting sauces, pickles and condiments. I’ve yet to find the quality inflection point for oyster sauce, pickled chiles, chile sauces (like sambal oelek or Sriracha), fermented bean sauces (like hoisin or Sichuan broad-bean chile paste) or fish sauce. Soy sauce has a reputation for longevity, but I keep mine in the refrigerator to fend off the fishy aromas that can start to develop after a few months in the pantry.
We all know what a rotten egg smells like, right? Why else would it be a benchmark for describing so many other bad smells? But how many times have you actually smelled one: Once? Twice? Never? Probably never, at least according to the impromptu poll I conducted on Twitter. That’s because it takes a long time for eggs to go bad.
How long? The Julian date printed on each carton (that’s the three-digit number ranging from 001 for Jan. 1 to 365 for Dec. 31) represents the date the eggs were packed, which, in most parts of the country, can be up to 30 days after the egg was actually laid. The sell-by stamp can be another 30 days after the pack date.
That’s 60 full days! But odds are good that they’ll still be palatable for several weeks longer than that.
We’ve all accidentally poured some clumpy spoiled milk into our cereal bowls. It seems as if our milk is perfectly fine, until it’s suddenly not. How does it go bad overnight? The truth is, it doesn’t. From the moment you open a carton of milk, bacteria start to digest lactose (milk sugars), and produce acidic byproducts. Once its pH hits 4.6, that’s when casein (milk protein) clumps.
Want longer-lasting milk? Look for “ultrahigh temperature,” or “UHT,” on the label. Milk in these cartons has been pasteurized at high temperatures (275 degrees Fahrenheit: hot enough to destroy not only viruses and bacteria, but bacterial spores as well), then aseptically pumped and sealed into cartons. Most organic milk brands undergo UHT. (Bonus: In the blind taste tests I’ve conducted, most people preferred the sweeter flavor of UHT milk.)
And as for baby food — the only food with federally mandated use-by dating — that expiration date represents the latest date that the manufacturer can guarantee that the food contains not less of each nutrient than what is printed on the label, or, in the case of formula, that it can still pass through an ordinary rubber nipple.
Rest assured that, if there’s a zombie apocalypse, you’ll still be able to eat the baby food and gain some nutritional benefit.