Regular yogurt doesn't last long out of the fridge. According to the US Department of Agriculture, you should really throw out yogurt if it's been sitting out at room temperature for longer than two hours. But what about yogurt that you've carefully kept in your fridge that happens to be past its sell-by date? Can you eat expired yogurt, or, at least, yogurt that's outlasted its listed expiration date?
The short answer is basically yes. You can eat yogurt past its "expiration" date or, at least, the sell-by date that's listed on the yogurt's packaging. As Chris Bernstein of the USDA's Food Safety and Inspection Service explains in a video posted to the USDA's YouTube account, "Many products might have a sell-by date of, say, April 1. But they could be good in your pantry for another 12 or 18 months, and by throwing those out, what you're doing is contributing to food waste in the United States."
The listed sell-by date is usually guidance for stores more so than for consumers. While conventional yogurt isn't going to last in your fridge for a year, yogurt is generally safe to eat for up to two weeks after you bought it, according to the USDA's FreshKeeper app. That holds true even if the date range extends past the listed sell-by date. So if you bought yogurt on April 1, and the sell-by date is April 2, you can still eat that yogurt until April 15 or so.
You should still be on the lookout for the signs of spoiled yogurt, though. By far the easiest way to tell if your yogurt has gone bad is if you see mold. But the other signs of yogurt spoilage are, admittedly, a little less obvious. As Jeanne Goldberg, a professor at Tufts University's Friedman School of Nutrition Science and Policy, told the school's alumni magazine, it's because "Taste and smell are not reliable indicators of food safety. Some bacteria that cause food-borne illness do not have off-flavors associated with them."
Keeping track of the amount of time that yogurt's been in your fridge is the best way to avoid eating yogurt that's gone bad. If it's two weeks after the sell-by date, you should probably toss that container. You can also make sure your yogurt lasts as long as possible by storing it correctly: Always in your fridge and always in a container with a sealable lid. And remember that unopened containers of yogurt are more likely to last past the sell-by date than those you've already opened and resealed. Because even though you can eat expired yogurt, you shouldn't eat spoiled yogurt.