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Is It OK to Put Warm Leftovers in the Fridge? The Answer Is Not What You’d Expect

published Oct 10, 2024
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Credit: Meghan Splawn

Anyone who has cooked a big holiday meal or celebratory feast knows that the aftermath can be daunting. No one wants to be wasteful and toss it all, but when faced with a myriad of bowls, pots, and platters of leftovers, some cooled down and some still hot, it can be hard to navigate not just the best way to tackle it all, but the safest. Even dinner leftovers can be confusing. Should you let them cool to room temperature before refrigerating or stick them in right away? 

Food safety has been thrust back into the spotlight recently after content on social media surrounding rice, specifically reheated rice, went viral. The topic spurred a flurry of opinions, videos, and articles debating both sides. But is rice any different than a big pot of beef chili or a roast turkey? Not really. “Ricegate” is actually an issue of proper food handling and food storage, and those best practices are largely the same regardless of the food in question.  

I consider myself pretty savvy when it comes to food safety. When I worked as a line cook at a highly respected Manhattan restaurant or on massive television productions like Iron Chef America, food safety was of the utmost importance. But there, I had the benefit of a bottomless industrial ice machine, powerful walk-in refrigerators, and all the large pans and storage containers of every size and material anyone could need for quickly cooling down hot foods. Now, as I work from home, my ice cube trays yield minimal cooling power, and just leaving things to cool on their own goes against what I know. So, is there another way? I wondered, can you put hot food in the fridge? 

To fully understand the answer to that question and the science behind it, I spoke to Dr. Benjamin Chapman, a food safety specialist, professor, and department head of Agricultural and Human Sciences at North Carolina State University. Dr. Chapman’s knowledge blew my misconceptions out of the water and has changed how I tackle food storage at home for good. 

So, Can You Put Hot Food in the Fridge?

YES! Not only can you put hot food in the fridge, but you should, as long as you do so correctly. In matters of food safety, cooling food down quickly is the name of the game. To be clear, we are not talking about baked goods like loaves of bread, cookies, or cakes. We are talking about cooked foods, like meat, grains, or vegetables, which start hot and cool after cooking. 

Dr. Chapman shares that many of us grew up thinking, “Oh gosh, we couldn’t put the turkey in the refrigerator right away because it’s a food safety issue, and it’s totally not. [The] goal is always to chill as quickly as you can.” Getting cooked food into the refrigerator as soon as possible, whether fully cooled or not, is the best way to prevent food spoilage and an environment for foodborne illnesses to grow.

What Is the “Danger Zone”?

The danger zone is a term used to describe a range of temperatures, between 40°F and 140°F according to the FDA and the USDA, where, over time, cooked food can grow bacteria. Dr. Chapman clarifies that the danger zone is the most ideal setting for most of the pathogens that we worry about to grow.” The significance of the danger zone is that it helps dictate how long you can leave cooked food unrefrigerated since it is the combination of temperature and time that can cause food to become risky or unsafe to eat. 

Dr. Chapman also points out that there are variables regarding the danger zone and that “it’s not magic. It’s not like you get to 42°F, and all of a sudden, bacteria grows at the same rate as it does at 110°F. … Between 90°F and 110°F is way more dangerous than 43°F or 48°F because it’s the ideal temperature for most pathogens associated with the gastrointestinal tract to grow.” 

How Long Should You Let Food Cool Before Refrigerating?

There is no need to cool cooked food before refrigerating, so long as it is stored correctly. Yes, really. Dr. Chapman explains that “it’s a myth. A pervasive myth.” The idea that food needs to cool first has been handed down from generation to generation but is based on outdated technology. Dr. Chapman elaborates, “Refrigerators work different now than they did back then. Our refrigerators maintain a constant temperature where refrigerators of like three generations ago would cycle. They would get warm, the condenser would kick on, and it would cool the temperature down again. And if you put hot food into like a 1950s refrigerator, you have the ability, especially if there is a lot of it, to mess with the condenser and essentially break your refrigerator.”

Rather than considering how long to wait until putting your food away, be proactive and focus on minimizing how long the food sits out and the best way to store it. Does this mean you should rush through meals or place hot pots directly into the refrigerator? No. While the temperature of cooked food is important, time is also a major factor. Dr. Chapman notes that “even the bacteria that we think about being linked to [leftover] pasta or rice, it takes some time for that bacteria to even recognize that it’s in the right environment to grow.” The FDA and the USDA recommend keeping food at room temperature for up to two hours, and only half that if the ambient temperature is 90°F or above.  

How to Properly Store Food

The type of food you are working with will help dictate the best way to properly store it, but one universal consideration is speed. You want to cool food down as quickly as possible to avoid the growth of bacteria so when packing up cooked food, think about how you can help that process along. A little bit of planning will make this process infinitely easier. Stock up on different sizes and shapes of containers and reusable storage bags, and note whether they are freezer-safe if storing in the freezer is part of the plan. If food is correctly cooked and cooled down, leftovers, from rice to chicken, will be safe to eat.

For thick foods, like mashed potatoes or a hearty stew, Dr. Chapman advises that when you pack up, “you don’t want [the food] any thicker than 2 inches of density because the more dense it is, the harder it is to cool the center of that food.” Food storage bags can be a great option because you can press the contents flat, creating more surface area to cool the food quickly. Foods that can’t be easily stored in bags, like brothy soups, should be divided between smaller containers, and the shallower, the better. Even something brothy, “If it’s in a large enough container, that center of that container may take hours and hours to get below 41 degrees,” Dr. Chapman explains.

If the food is still steaming, leave the lid or covering open just a touch so that the heat can escape and the cool air of the refrigerator can circulate into the hot food. For large cuts of meat, like a roast turkey or ham, it is best to carve the meat first versus putting the whole thing in the refrigerator.

What NOT to Do

  • Do not put large hot pots of food or cuts of meat in the fridge: So, you made a huge pot of chili for a party the next day, and it would be so easy to just put the pot in the fridge instead of portioning it out. How bad can it be? Dr. Chapman explains that it can be very bad. “What happens is that you have all these gas formers and spoilage microorganisms … in the middle of that pot, and they are not going to get cool enough, quick enough, and so you end up leading to terrible situations or just terrible smelling, just awful, gas forming in the refrigerator.” Similarly, roasts that have not been broken down or carved into smaller pieces will hold the heat for a long time and not create any space for air to circulate and cool the food in a timely manner. 
  • Do not tightly seal containers of hot food: Dr. Chapman shares that there has been recent data proving that in the question of covered versus uncovered food in the refrigerator, “uncovered matters. It allows for the steam and the heated air that’s right above the food to escape into a larger container.” Leave one corner of the lid ajar until the food has cooled, and then fully seal the container. 
  • Do not pack dense foods in tall, deep containers: The thicker and denser the food, the less air can circulate to cool it down, and this is especially true if it’s packed into a large, tall container. If you do not have a shallow storage container or bag, spread it in a thinner layer in a bowl or on a rimmed baking sheet until cool, then pack it away.
  • Do not use the wrong packaging if freezing or overfill the containers: When choosing storage containers, the material, glass versus plastic, doesn’t matter unless you want to put the hot food directly into the freezer. Dr. Chapman recommends that since glass is more rigid and “water expands when it’s frozen, it could certainly lead to shattering the glass if it’s not glass that rated for freezers.” Additionally, leave room at the top of the container for the food to expand and opt for a lid with some flexibility so that when the food is frozen, it doesn’t crack the lid or push it off the container. 
  • Do not forget about your food: It happens. Time slips away, or there is a miscommunication, and suddenly, you are faced with food that has been out for 8 to 12 hours. Maybe you forgot because you were waiting for the food to cool before putting it away. In this case, caution is the best call. It’s better to toss the food than risk illness. Dr. Chapman reminds us that “the best practice is getting it into the fridge as fast as possible. So if it’s not going to be consumed, and you know that, then let’s get it cooled down.” 

This article originally published on The Kitchn. See it there: Is It OK to Put Warm Leftovers in the Fridge? The Answer Is Not What You’d Expect