Is It Safe to Refrigerate Hot Food? Here's What Food Safety Experts Say

Whether you're saving leftovers or prepping meals, storing food in the refrigerator is an inevitable part of cooking. When the time comes, you might wonder if you can put hot food in the refrigerator, as many home chefs always let it cool on the counter first. The reason? It's thought that refrigerating hot food is unsafe, but the myth is up for debate. In fact, waiting too long to refrigerate food can promote the growth of harmful germs, potentially leading to foodborne illness. That being said, how do you refrigerate hot food correctly? We spoke to food safety experts, and they shared the best methods, plus how each one can keep food safe.

Why You Should Avoid Cooling Food at Room Temperature

Due to the belief that it's unsafe to put hot food in the refrigerator, it's common practice to let food slowly cool at room temperature. However, this is not recommended. That's because the food won't cool quickly enough to prevent bacterial growth, says Vanessa Coffman, Ph.D., program director at Stop Foodborne Illness. She explains further: "Foodborne bacteria can double in number every 20 minutes when food is left in the temperature danger zone between 40 and 140 degrees Fahrenheit." Thus, to stay safe, food should cool to 70 degrees within two hours, then to 41 degrees Fahrenheit or lower within the next four hours (but the faster, the better), says Coffman.

Depending on the type of food and the temperature in your kitchen, it might be able to reach 70 degrees Fahrenheit within two hours on the counter, notes Coffman. "But reaching the final safe temperature of 41 degrees at room temperature is virtually impossible, unless your kitchen doubles as a walk-in refrigerator," she says. 

Why You Should Never Put Hot Food Straight into the Refrigerator

Putting a pot of hot food straight into the fridge can also pose a safety risk, as the food may not cool evenly in the vessel. If this happens, illness-causing bacteria may grow and flourish in warmer parts of the food, potentially making you sick when you eat it. Similarly, big portions of hot dishes can increase the temperature of your fridge, rendering other food unsafe.

The Right Way to Store Hot Food in the Fridge

Before putting hot food in the fridge, you'll need to quickly cool the food using a safe method. Here are some options food safety experts use:

Divide Food Into Smaller Portions

One approach is to split the food into multiple smaller containers. "Dividing the food into smaller portions increases the surface areas of the food, allowing the heat to release into the surrounding area more quickly," explains food scientist and food consultant Bryan Quoc Le, Ph.D. The smaller volumes also mean the food won't insulate itself as well, allowing the center of each container will cool down more quickly, he adds. "This keeps food safe because it gets out of the danger zone sooner," says Le. 

For best results, use metal or glass containers rather than plastic ones. Metal conducts heat better than plastic, which can make the cooling process more effective, says Coffman. Meanwhile, glass is heat resistant and lacks the risk of microplastics leaching into the food, notes Le.

Chill Food in an Ice Bath

You can also place hot food in an ice bath before storing it in the refrigerator. This will significantly lower the temperature of the food, helping it move quickly through the temperature danger zone. 

Here's how to do it, according to Coffman:

1. Fill a clean sink or large pot with ice water. Use enough water so that it fully comes up the sides of the food container, but doesn't spill in.
2. Place the container of hot food in the sink or pot.
3. Stir the food frequently.
4. Use a clean food thermometer to check the internal temperature of the food. It should cool to 70 degrees Fahrenheit within two hours. You'll likely need to refresh the cold water and ice.
5. Once the food reaches 70 degrees, transfer it to the refrigerator to finish cooling to 40 degrees or below.
   

"It's important to note that this method works better on some foods than others," shares Le. "For example, pieces of cut-up meat in a container don't transfer their heat as well as a liquid gravy that fully conforms to the container, thereby transferring heat better via the container's walls," he explains.

Other Ways

For soups, stews, or other liquids, you can add ice to help lower the temperature safely and quickly, says Coffman. You can also stir food frequently to release trapped heat, she adds.

Can You Put Hot Food in the Freezer?

You may be tempted to place hot food directly in the freezer to rapidly cool it, but this is not recommended. The practice can raise the temperature inside the freezer, causing nearby frozen foods to thaw, explains Coffman. 

How to Cool Food Before Freezing

Start by properly cooling the food using one of the methods listed above. Once the food has reached 40 degrees Fahrenheit, it can be transferred to the freezer.

How Long Can You Leave Food Unrefrigerated

If cooked food must be kept at room temperature for any reason, never leave it for more than two hours. This is the maximum time food can stay in the temperature danger zone. This timeframe is shortened to one hour on hot days (i.e., 90 degrees or above), according to the experts at the USDA.