How Long Can Dairy and Eggs Sit Out Safely? Surprising Answers From Experts

If I am in the kitchen with you while you’re cooking, and I see you take milk out of the fridge, pour it, and leave it on the counter, that carton will not be there the next time you turn around. I will have dashed forward and put it back in the fridge. Same with butter and eggs. This can be annoying to people—my husband is often baffled at where his ingredients went. While I long believed I was some kind of food-safety fairy saving my family from getting poisoned, recently I wondered whether I was being maybe too cautious. So I dug into how long milk, butter, and eggs can actually stay out of the fridge before going bad. I learned a lot! Here’s what the experts said.

Milk

The FDA’s general rule for all perishable foods, including milk, is that they can stay out of the fridge for two hours, or one hour if the surrounding temperature is 90°F or higher. All due respect to the FDA, but that seems way too long to me. Milk? One to two hours? Did they mean to say “seconds”?

It is true, though, says dairy expert Nicole Martin. She explained to me that over time, at warmer temperatures, the bacteria in pasteurized milk multiply. It doesn’t happen right away, but it does happen more quickly the hotter it gets. “When milk temperature increases, the bacteria grow faster. There’s nothing magical about 90°F, but many types of bacteria grow very well at that temperature,” she said. “The recommendation to reduce the amount of time milk sits out at that temperature is simply to reduce the amount of bacterial growth that can occur.”

What’s more, leaving milk out for longer than the recommended time doesn’t necessarily cause instant spoilage. It just reduces the overall shelf life of the milk. “Let’s say you expect the milk to last another week based on the date stamped on the carton, but you leave the milk out of the fridge for three hours on a warm day,” Martin explained. “That milk may not make it another week before it starts to develop unpleasant odors or flavors.”

OK, so my milk carton is not going to turn into a bubbling cauldron of pathogens if my husband leaves it on the counter while he’s stirring the pancake batter. Still, even Martin says she’s diligent about keeping her milk cold. “Nobody in my house is allowed to leave the milk on the counter!” she told me. “Not because I worry about the safety of the milk, but because I know that keeping milk cold preserves the quality of the milk—my milk is going to taste great longer if I simply keep it cold.”

Bottom line: It’s best practice to keep your milk cold, but don’t panic if it stays out for a bit. “I always recommend using your senses,” Martin said. “Smell it and taste it—if you don’t notice any change in those aspects, go ahead and drink it.”

Eggs

The official guidance from the USDA is that eggs should not be left out of the fridge for more than two hours. The risk here is salmonella, according to Martin. In the U.S., unlike in many other countries, eggs are washed before being sold. The washing process removes the natural membrane that protects the eggs from bacteria, which is why our eggs need to be refrigerated. As with milk, “when temperatures are higher, bacteria grow faster” in eggs, Martin said.

So why do so many baking recipes call for room-temperature eggs? Is that safe? “It’s so the eggs mix and incorporate easily with other ingredients,” said Trung Vu, a baking expert at the Institute of Culinary Education. “For example, if eggs are too cold, it can cause softened butter to seize, meaning the butter will resolidify, and this could lead to lumps of butter in the dough.”

And it is safe, he added, because eggs will come to room temperature in about an hour, which is well within the recommended time limit.  “You can hasten the process by placing the eggs in a bowl of warm water, which will take about 15 minutes to bring to room temperature,” he said.

Setting my mind further at ease, both Martin and Vu told me that properly cooking the eggs will kill any salmonella that grows. “Cook eggs and products containing them to at least 160°F,” Vu said.

Bottom line: You can leave eggs out of the fridge for two hours, as long as you cook them thoroughly.

Butter

“They leave butter packets out at restaurants!” my husband once protested after I threw a stick of butter back into the fridge while he was cooking. “My grandmother always left out the butter dish! The texture is better if it’s soft and spreadable!” I told him that may be true, but it just felt dangerous to let a stick of butter hang out on the counter.

I hate to admit it, but my intuition was off. (This is why we must research facts, I guess.) Butter is an exception to the two-hour rule and can actually stay at room temperature for up to two days! Martin explained the science to me: “Butter is less perishable than milk because it doesn’t have as much water activity, which is a measure of how much water is available for microbes to use to grow,” she said. “Salted butter has even less water activity than unsalted butter, so microbes either won’t grow or won’t grow as quickly in salted butter.”

Whether salted or unsalted, the primary risk of leaving butter out too long is that it will smell and taste rancid, not that you’ll get sick from microbes, Martin added.

And echoing my husband, Vu said, “I like to let butter sit out to soften before cooking. Many restaurants and bakeries will leave butter to sit out overnight for use in the following day’s production. I’m OK baking with butter that’s been out of the refrigerator for a while.”

All right, but if we’re going to start leaving butter out in my house, it has to be in a pretty dish or something. A partially unwrapped stick of butter oozing into the counter still gives me the heebie-jeebies.

Bottom line: Butter can stay out for up to two days because it’s less perishable than other dairy products.