Users on TikTok and X (formerly Twitter) are freaking out over reheated rice.
Concerns over leftover rice first blew up in late 2023 and has since taken off again in February as users are scared of getting food poisoning from the meal.
A TikTok video from a second-year medical student showed how the user can't "comfortably" reheat rice again being in her field. Recipe website Food52's food editor Em Ziemski later explained why there was this fear, calling it "Reheated Rice Syndrome." So what is it, exactly?
Reheated Rice Syndrome or Fried Rice Syndrome refers to food poisoning you get from Bacillus cereus, a bacteria that grows on your rice. Ziemski added that hospital workers have said this type of food poisoning is "the worst they've ever seen."
How can you get sick from reheated rice?
Leftover rice, when left out for too long can have Bacillus cereus, or B. cereus, form on it.
According to registered nutritionist-dietitian (RND) Genesis Rivera, who topped the ND board exams in November 2023, B. cereus is a spore-forming bacteria that's heat resistant and thrives in the damp environment of rice. This bacteria is also found in soil and comes in contact with potatoes, root crops, and starchy food.
B. cereus causes two types of food poisoning, diarrheal and emetic (vomiting). And because the bacteria is heat-resistant, it can still be there even when you reheat your food, as per the Cleveland Clinic.
"Kapag ang bacteria, spore-forming, talagang heat resistant siya, mahirap siyang patayin," he told PhilSTAR L!fe.
Kathryn Gino, also an RND, added that in food safety there's what they call a temperature danger zone (TDZ) for your dishes, which is from 4.4 to 60 degrees Celsius. "When leftover rice is left under this condition, bacteria such as B. cereus multiply fast which can compromise food safety," she told L!fe.
To avoid B. cereus from forming, both RNDs said that leftover rice should only be left out for two hours at room temperature.
"Di kasi pwedeng lumagpas ng two hours yung rice sa room temperature. As much as possible kung alam nating di natin mauubos yung rice or feeling natin na kailangan pa siyang gamitin the next day, kailangan [ilagay sa refrigerator] within two hours," Rivera explained.
Avoiding reheated rice syndrome
In addition to the two-hour rule, leftover rice should be stored properly in your refrigerator to keep it away from any bacteria.
Rivera told L!fe that your fridge should be below 5 degrees Celsius and should be kept in clean containers and handled with sanitized hands.
When you reheat your rice, you should let it reach 74 degrees Celsius whether in the microwave or on the stove.
"It really boils down to the food safety practices kasi kailangan din malinis yung kamay, malinis yung pinaglalagyan ng kanin, yung ref para siguradong pwede pang kainin yung leftover rice," he said.
If stored properly, your leftover rice can last a couple of days, according to Gino.
"Under ideal conditions, leftover food in the fridge usually lasts three to four days," she said.
Rivera added that rice can even last up to six months if frozen. "Lagyan lang ng tubig at siguraduhin na aabot ng 74 degrees celsius," he advised as rice goes through retrogradation, a process where it loses its flavor and begins hardening.
So is it safe to eat your leftover rice?
It really depends on how you store it, according to the nutritionists. If you follow the protocols they gave above, and store and heat them at the right temperatures, it should be safe to eat.
As a spore-forming bacteria, B. cereus isn't visible to the naked eye and can only be seen through a microscope so there's really no physical way to tell if your rice has been compromised.
But as Rivera said, when it comes to food safety, "When in doubt, throw it out."
"Mahirap kasi yung kutuban. As much as possible, hanggang two hours, four hours lang at follow ang storing protocol. Pero pag duda, itapon."
PhilSTAR L!fe has also reached out to the Department of Agriculture regarding fried rice syndrome.