Last Updated on March 2, 2023 by Practical Cooks
It may sound odd to wonder if you can put warm rice in the fridge. After all, it’s already cooked. What does it matter if it’s warm or not, right?
Well, when it comes to refrigerating warm rice, the concern is the fact that storing warm rice in a cold environment like a fridge may cause it to take longer to cool down.
This means any existing bacteria will have a longer time to stay active and spread than if the rice was cooled quicker before being placed into the fridge. In a way, refrigerating warm rice may lead to food poisoning later. Don’t put warm rice in the fridge to avoid such a possibility.
If you don’t believe us, that’s okay. We’re about to dive further into bacteria, why warm rice should avoid the fridge, what happens when you put warm rice in the fridge (hint, it’s not only bad for the rice), and how you should handle and store leftover rice.
Lastly, we’ll take a look at how long the rice can remain unrefrigerated before you need to consider tossing it out.
Rice and Bacteria
Rice grows close to the ground. As a result, rice is exposed to a bacteria called Bacillus cereus that’s commonly found in dirt. Bacillus cereus is also a common cause of food poisoning, with symptoms that can include diarrhea, nausea, and other abdominal discomfort.
When it comes to the cooking and storage of rice, it’s important to know Bacillus cereus can survive a wide range of temperatures. This makes its presence common in cooked and reheated rice dishes.
In dry, uncooked rice, any Bacillus cereus that may be present tends to be dormant. However, when water is added, the bacterial spores are activated. It’s only through the cooking process that bacteria dies, making your rice safe to eat. Temperatures above 165°F (74°C) are sufficient to kill the bacteria. That being said, Bacillus cereus can form spores that are heat-resistant and can survive the cooking process. This can, of course, cause food poisoning later.
So, the goal should be to thoroughly cook your rice and serve it hot. Hopefully, you won’t have any leftovers.
But what if you do?
What Refrigeration Does to Leftover Warm Rice
The concern with leftover cooked rice is usually how long it’s been sitting out. And this is a perfectly logical concern. Once any cooked food drops below 140°F, it enters the food safety “danger zone”. This means it’s reached an ideal temperature for bacteria to start growing, including any heat-resistant Bacillus cereus your leftovers may have.
So, you might think that refrigerating warm rice is the right thing to do, right? After all, you don’t want any surviving bacteria or new bacteria to take hold. If you cool it fast enough in the fridge, it’ll be fine.
Not so much. If you pack hot or warm rice into a storage container and place it in a fridge, the center of it will take longer to cool. You essentially risk storing your rice with active spores that have more time to spread before the cold finally calms them down.
Instead, it’s better to take leftover rice and spread it out on a baking sheet or other flat surface to allow it to cool faster. Then place it in an airtight container or two and place it in the fridge. This way, it will get colder even faster, keeping any bacteria present from spreading.
- Spread hot or warm rice on a flat surface
- Allow to cool for up to 15 – 30 minutes
- Place in airtight containers in the fridge
Are there Tips for Refrigerating Warm Rice?
Just because we don’t recommend refrigerating warm rice doesn’t mean you can’t refrigerate hot or warm rice. Yes, you may risk food poisoning as a result, but if there’s a good chance of leaving your rice out longer than it should, you may want to go ahead and refrigerate it warm.
Nothing is guaranteed, of course, but there is a way to refrigerate your rice while it’s still warm. The key is to break up the rice into smaller portions for storage. Instead of one big airtight container where the denser center will take longer to cool down, put your leftover rice in several containers.
This will ensure the rice cools faster, keeps bacteria inactive, and minimizes the potential for food poisoning later.
Breaking the rice up into smaller storage containers may be enough to cool the rice off on its own. However, if it’s still warm, more containers are better than just one or two.
What Else Does Warm Rice Affect?
Warm rice can also hurt the cooling system of your fridge. It’s not an immediate effect though. Essentially, the more often you place hot or warm food in the fridge, the harder it has to work to keep everything in the fridge cool. Over time, this can wear out your compressor and lead to costly repairs.
How Do You Reheat Rice?
Because rice may contain Bacillus cereus or other bacteria, it should be reheated thoroughly. This means you want to see steam coming off it when it’s done. Of course, you can also use a thermometer to make sure it reaches 165°F again.
You can reheat it in the microwave or on the stove. In either case, add a splash of water to help re-hydrate the rice.
Can You Use a Freezer?
Using a freezer is often better than using a fridge, especially if you cool down the rice immediately after cooking. The freezer will help preserve moisture and minimize drying and hardening.
How Long Do You Have to Store Cooked Rice?
Approximately 1 hour.
What Do You Do with Rice that’s Been Sitting for More than an Hour at Room Temperature?
Toss it to be safe. As they say: if in doubt, throw it out!