Expiration Dates Tend To Be Loose Recommendations, but These Are the Foods You Shouldn’t Keep Past Due

POV: You’re ready to dig into a big ol’ tub of hummus, and though you could’ve sworn you purchased the item less than a week ago, you’re distraught to find that the expiration date has long come and gone. Sigh.

Before you head straight to the trash bin with your doomed container of roasted red pepper hummus, keep in mind that expiration dates actually tend to be recommendations, rather than hard-and-fast deadlines.

To learn more about what the slightly rubbed-off dates stamped on the side of your hummus container (etc. etc.) really mean, we spoke with Francisco Diez-Gonzalez, PhD, director at the Center of Food Safety at the University of Georgia, who shed light on how to approach these foods. According to the expert, in most instances, foods are more than likely safe to consume after their expiration—however, there are certain foods that should be approached with more scrutiny. More ahead on interpreting expiration dates and the foods more prone to spoilage that aren’t worth risking eating past their date.

A deep dive explanation of what expiration dates really mean

According to Dr. Diez-Gonzalez, a food safety expert and professor, expiration dates aren’t as precise or as stringently applied you likely assume. “Expiration dates mean that a company can guarantee the full quality of the product if it’s consumed within that period of time. It doesn’t necessarily mean that the product is going to go bad the moment that the expiration date passes,” Dr. Diez-Gonzalez says. Basically, they aren’t a hard deadline for when the food will spoil. Rather, most best-by dates indicate a product’s estimated peak quality.

From a consumer perspective, this is important for several reasons. “If a product goes bad before the expiration date, the consumer can claim a refund,” Dr. Diez-Gonzalez says. However, he notes that if a customer consumes the product beyond the expiration date, a company has a valid case as to why it may not be liable in the event that someone becomes ill. What’s more, Dr. Diez-Gonzalez emphasizes that expiration dates are not based on safety measures (aka, whether a product can make you sick or not) but rather on the guaranteed quality of a product until a certain point in time (aka, whether a product is going to taste good or not).

According to the professor, this tends to be the number one misconception when interpreting expiration dates. “Products aren’t going to be unsafe the moment an expiration date passes, which is a very common misconception. The way companies determine these expiration dates is often somewhat of a guessing game,” Dr. Diez-Gonzalez says. Although mathematical models or trial-and-error experiments may be associated with determining an appropriate expiration date for a product, several factors can alter these estimations, which is important to keep in mind. Namely, environmental factors—like how this product was stored and at what temperature or if there was a risk of contamination once the product was opened—which can make expiration dates irrelevant altogether in terms of food safety for a consumer.

“Products aren’t going to be unsafe the moment an expiration date passes, which is a very common misconception. The way companies determine these expiration dates is often somewhat of a guessing game.”—Francisco Diez-Gonzalez, PhD

The foods a food safety expert advises against keeping past due

While yes, expiration dates tend to be loose recommendations, Dr. Diez-Gonzalez does note a few categories of foods he highly advises against keeping past due. At the top of the list are refrigerated foods, especially milk, cheese (mainly soft, fresh cheese), raw vegetables that require refrigeration, prepared foods, raw or thawed meat (which should be consumed within three to five days of the packaging date), and bagged lettuce—all of which are subject to spoiling very quickly.

At the top of the list are refrigerated foods, especially milk, cheese (mainly soft, fresh cheese), raw vegetables that require refrigeration, prepared foods, raw or thawed meat (which should be consumed within three to five days of the packaging date), and bagged lettuce—all of which are subject to spoiling very quickly.

Conversely, Dr. Diez-Gonzalez also says that some foods might have an expiration date months and months ahead yet may spoil before even reaching that designated date. “If a product is unopened, its characteristics will remain intact and not be subjected to external contamination. However, the moment you open a product—especially refrigerated ones or ones that require refrigeration upon opening—it’ll begin to spoil faster because it’s been introduced to external contamination at that point. For example, if you dip a spoon into a jar of tomato sauce and refrigerate it, you’ve contaminated the product,” Dr. Diez-Gonzalez says. Similarly, he strongly advises against drinking directly from a jug of milk or juice—despite what you may have seen in the movies—as the thousands of bacteria that live in your mouth can be transferred into the container and accelerate its spoilage.

That said, how quickly a product spoils can also depend on its packaging and ingredients. Dr. Diez-Gonzalez notes that some products are designed to maintain freshness for as long as possible in mind or have characteristics that help naturally prolong their preservation. “Ketchup—or fermented foods like pickles or sauerkraut—are an excellent example because of their high acidity, which makes them more resistant to spoilage or the growth of harmful microorganisms. Products like ketchup, mustard, and mayonnaise are made with highly acidic vinegar that helps prevent microbial growth,” he says. Still, they can spoil. As a rule of thumb, he recommends keeping products like these condiments no longer than a few months once opened—even if their expiration date is years ahead.

On the flip side, Dr. Diez-Gonzalez notes that unopened frozen foods (packaged in a sterile, food-safe facility) that have not been thawed and refrozen are much more flexible regarding expiration dates. However, their flavor may diminish over time.