Is It Safe To Eat Leftover Rice? Let's Find Out

8 min read
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Feb 13, 2024
Is It Safe To Eat Leftover Rice? Let's Find Out
Rice should be cooked to a safe temperature, but that doesn't mean you have to discard any leftovers.
Are you a fan of rice? Do you ever store it in the refrigerator to consume later? Also me! Those are highly relatable and prevalent characteristics of us.
Regrettably, there has recently been a mini-pandemic regarding the dangers of eating rice that is several days old on social media. Though exaggerated, there is a modicum of truth to the warnings.

Absolutely, it is okay to eat reheated rice

I'll begin with the conclusion before delving into the reasons for it. Those who advise against reheating leftover rice or who suggest that doing so can quickly lead to death are either grossly uninformed or grossly exaggerated.
As long as the rice never remained in the danger zone for an extended period of time, you can consume it warm. 40 to 140 degrees Fahrenheit, or warmer than a refrigerator but lower than cooking temperatures, is considered the danger zone. Sincerely, you should be adhering to the safe time restriction of two hours for all of your cooked, perishable meals.
You're not taking any big chances if your rice made it from the cooktop to the refrigerator in that amount of time. Then, just like with other leftovers, your rice will keep for several days.
However, how long has it been OK to leave rice on the counter for hours while you eat supper, tidy up, or become distracted? Then it's true that you ought to discard that rice.

How rice can cause food poisoning

All cases of food poisoning are brought on by toxins produced by microbes like bacteria. Although a wide variety of microorganisms can thrive on rice, Bacillus cereus, or B. cereus for short, is the one that raises the greatest concerns.
That's "cereus" as in "cereal," by the way; while it may wind up in almost any food and lives in the soil, it's most known for hanging out in grains like rice.
B. cereus, like all bacteria, can exist as individual cells that feed on the moisture and nutrients found in food. Nothing noteworthy thus far. However, B. cereus is one of the few foodborne bacteria that produces spores, which are similar to eggs in that they carry the progeny.
Because the spores are heat-resistant, they persist even after boiling the food and killing off the adults. In actuality, they will start growing immediately since the cooling process that follows frying causes them to germinate.
Additionally, the B. cereus bacteria have the ability to create an emetic toxin, which is a poison that causes vomiting, while they are growing. The so-called "fried rice syndrome" or "reheated rice syndrome," which some people attribute to leftover rice, is caused by this toxin.
In short, the primary distinction between B. cereus and the majority of other food poisoning bacteria is that heat does not eliminate the toxin that causes vomiting.
Reheating leftovers to 165 degrees, also known as "til steaming" or "until piping hot," usually works well. In the face of a good microwaving, B. cereus chuckles. Preventing B. cereus growth and remembering to eliminate it are the best ways to ensure that it does not cause illness.

But can’t B. cereus kill you? 

Although food poisoning from B. cereus on leftover rice can cause vomiting, more serious complications are quite unlikely to occur. The symptoms of emetic B. cereus usually include nausea, vomiting, and cramping in the stomach, and they usually last for less than a day.
I advise against purchasing it because it's not enjoyable. However, the alarming claims that eating leftover rice puts people in the hospital are exaggerated.
B. cereus can cause two different types of food poisoning: the sort we are talking about here, which is caused by starchy foods like rice, and a diarrheal variety that is more frequently caused by meat, vegetables, and dairy products.
Combining the two, the CDC calculates that there were, on average, 63,000 instances of B. cereus food poisoning annually between 2000 and 2008, resulting in 20 hospital admissions and no fatalities.
Thus, a third of one percent of instances required hospital care, but no one died. This does not imply that fatalities from this are improbable, only that TikTok's grave warnings lack a great deal of context.
B. cereus is not foodborne, yet it can cause severe sickness and even death. The various forms of B. cereus infections, as well as their consequences and risk factors, are described in this publication from the NIH for medical professionals.
The germs that cause the worst cases are linked to intravenous drug use, traumatic injuries, and medical devices like pacemakers and central lines. (Keep in mind that patients are contracting this type of the disease through infected wounds, as this is a common soil bacterium.) B. cereus infections typically occur after eye injuries and are linked to the eyes or start there before spreading to other parts of the body.
Yes, it is significant from a medical standpoint. Not sitting there in chilled rice bowls waiting for you.

The exact steps you should take to properly store and reheat rice

As previously indicated, rice can be safely reheated or eaten cold as long as it was prepared correctly. Let's review the specifics.
By the way, as much as I enjoy being your go-to resource for learning the science behind the rumors you may come across online, keep in mind that the USDA and many university cooperative extensions have a wealth of information about food safety available on their websites.
Compared to blogs, TikTok, or even big media institutions, these are far superior sources. As it is their job, food safety professionals are knowledgeable about this.
Now let's examine this paper on reducing foodborne illness caused by Bacillus cereus that was published by the USDA and the Institute of Food and Agricultural Sciences at the University of Florida. Does it advise discarding your rice? Not at all! It states:

Cooking or heating to a temperature of at least 145ºF (63ºC) and then warming for 15 seconds to 165ºF (74ºC) will kill the vegetative (actively developing) cells. Once cooked, the product cools quickly enough to stop any remaining spores from sprouting. It should be noted, nevertheless, that once poisons have created, they cannot be eliminated from food.
To stop the production of spores, keep hot foods above 135ºF (57ºC) and cold foods below 41ºF (5ºC). To adequately refrigerate leftovers, quickly cool them down to 41ºF (5ºC) or lower. To guarantee proper ventilation around the meal and quick cooling, make sure leftover containers are not stacked closely together.

Although they don't specify how long constitutes "rapid" cooling, they do cite rules stating that food shouldn't be left out for longer than two hours in other places.
Given that the temperature of a rice cooker set to "warm" is typically around 150 degrees Fahrenheit, eating rice that has been in there for hours is often acceptable, despite how disgusting this may seem.
To make certain that your rice cooker is indeed keeping the rice hot enough to stay out of the danger zone, you might want to use a thermometer if you do this frequently.
And if you treated the rice correctly at first, how long can you keep it in the refrigerator? Although there isn't a precise guideline for rice here, in general, cooked food can be kept for up to seven days if the temperature has remained below 41 degrees. (You should keep food in your refrigerator much below 41 degrees Celsius to ensure its safety and because cold food keeps better).
Anywhere in the mid-thirties would be ideal, as 32 is freezing.) For establishments such as restaurants, the seven-day rule applies; for the general public, three to four days is the recommended duration.
For reasons I don't fully understand, UK sources (such as this one from the NHS) frequently advise refrigerating rice for no longer than one day. However, American sources concur with the University of Florida.
A food safety specialist from the University of Wisconsin-Madison states that leftover rice may be stored properly for three to five days. She also mentions that one of her favorite lunches is cold rice salad.
In their own rice safety report, the University of California concurs and suggests a duration of three to five days. I will continue to eat my leftover rice and heed their counsel rather than that of the TikToks.

Frequently asked question

Is it safe to eat reheated rice?

Yes, it is safe to eat reheated rice as long as it was stored and reheated properly.

What are the risks of eating reheated rice?

Reheated rice can harbor Bacillus cereus bacteria, which can produce toxins that cause vomiting and diarrhea. However, these risks are minimized with proper handling.

How long can I store cooked rice in the refrigerator?

American sources generally recommend storing cooked rice for 3-5 days in the refrigerator, while UK sources recommend 1 day.

How should I cool cooked rice before storing it?

Cool the rice as quickly as possible, within 2 hours, by spreading it out in shallow containers or dividing it into smaller portions.

What temperature should I reheat rice to?

Reheat rice to an internal temperature of 165°F (74°C) throughout. Use a food thermometer to ensure safe reheating.

Can I reheat rice multiple times?

It's best to reheat rice only once to minimize the risk of bacterial growth.

Is it safe to leave rice out at room temperature for several hours?

No, it is not safe to leave cooked rice out at room temperature for more than 2 hours. This is when bacteria can grow rapidly and pose a food safety risk.

Where can I find more reliable information about food safety?

USDA, university cooperative extensions, and reputable food safety organizations are excellent sources for accurate information.

Is it true that eating leftover rice can kill you?

No, the claims about leftover rice causing death are greatly exaggerated. While B. cereus can cause food poisoning, serious complications are very rare.

Is rice cooker "warm" mode safe for storing rice?

It depends on the specific rice cooker. Most warm settings maintain rice around 150°F, which might be acceptable for a few hours, but use a thermometer to be sure.

Can I eat cold rice salad?

Yes, as long as the rice was cooked and stored properly, it is safe to eat cold.

I enjoy learning about food safety, are there other resources you recommend?

Yes, websites of USDA, university cooperative extensions, and reputable food safety organizations offer reliable and science-backed information.
Additional sources like University of Florida Health (UF) and University of California provide more accurate information.
Remember, these sources are often more trustworthy than blogs, social media, or even some media reports.