Does Unopened Cereal Ever Go Bad?

In a pinch, you may want to reach for the long-forgotten, unopened box of cereal at the back of your pantry. But how old is too old when it comes to the beloved breakfast staple? According to the U.S. Department of Agriculture (USDA), "most shelf-stable foods are safe indefinitely" — long past the date on the package. However, that doesn't mean the cereal will still taste as great as the day you bought it. "You'll know when you open the package if the food has lost quality," noted the agency.

The likelihood of spoilage also depends on the type of cereal in question. "Cereals with [more] fat are more prone to rancidity," explained Sharon Palmer, RDN, who spoke with the "Today" show. These higher-fat cereals typically include varieties that contain nuts, oils, or whole grains. As time goes on, cereals, especially fortified ones, are also prone to losing some of their nutritional value, as reported by Livestrong.com. While these cereals may not provide the optimal breakfast experience, they will still be "technically safe to eat," said the website.

Most sources agree: An unopened box of cereal will last far longer than its best-by date. But if that's the case, what purpose do best-by dates serve? According to Time, the best-by date is used by manufacturers to gauge a product's freshness. In other words, the date isn't an expiration date, though many people will equate the two in their minds.

This confusion prompts consumers to throw away items earlier than necessary and leads to significant food waste. As a 2013 study from the ​​Natural Resources Defense Council and Harvard Law School's Food Law and Policy Clinic explained, "An estimated 40% of food in the United States goes uneaten, and according to even the most conservative estimates, Americans waste 160 billion pounds of food each year."

With that in mind, you may wish to maximize the lifespan of your recently-purchased box of cereal — and luckily, there are actions you can take to keep it as fresh as possible. Per the "Today" show, cereal should be kept in a place that "minimizes exposure to air, heat and light," such as a "dry, closed pantry." Keeping your cereal sealed and away from moisture is also key to ensuring its freshness.