What is fried rice syndrome?

In this brief guide, we will answer the question “What is fried rice syndrome?”, and tell you why it happens. We will also discuss how to avoid getting fried rice syndrome and how to manage fried rice syndrome. We will also mention how to tell when rice goes bad.

What is fried rice syndrome?

Fried rice syndrome is a type of food poisoning which is caused by Bacillus cereus. The symptoms of fried rice syndrome are nausea, vomiting, profuse watery diarrhea, and abdominal cramps.

It is caused when rice is allowed to sit at room temperature after boiling it. It can also be caused by eating leftover cooked rice.

What happens is that B. cereus is present in rice. Rice contains spores of this bacteria so when cooked rice is allowed to sit out for longer periods of time, the spores begin to grow. The bacteria produces toxins which are heat and acid resistant so reheating or cooking the rice will have no effect on the toxins.

When ingested, these toxins will cause the foodborne illness known as fried rice syndrome.

B. cereus produces two types of toxins. One type of toxin is produced in the small intestine when B. cereus is ingested and the 2nd type is pre-formed in the contaminated rice.

Why does fried rice syndrome happen?

Restaurants often boil a large amount of rice at once and then let it sit at room temperature for hours before they fry it (as per the customers’ needs). This sitting period allows the bacteria to grow and produce toxins. 

As told above, these toxins are heat resistant. So, frying the rice again does not guarantee that it is free from contamination.

How to avoid fried rice syndrome?

In order to avoid fried rice syndrome, it is advisable to boil only small amounts of rice and not let it sit out at room temperature for more than 2 hours.

Since it is important to cool down the boiled rice before frying to avoid sogginess, do so in shallow bowls to allow for quicker cooling.

It is also important to refrigerate rice in an airtight container. The temperature of the fridge should be under 40 degrees.

How to manage fried rice syndrome?

The body typically fights off the infection on its own within 24 hours. However, it is important to stay hydrated as dehydration is a complication of food poisoning.

Rest and avoid taking heavy foods until you feel better.

How do you know when Rice goes bad?

You can tell when the rice has gone bad by looking for signs of spoilage. Since raw rice has a longer shelf life than cooked rice, and their signs of spoilage also differ, let’s look at these signs separately for both of them. 

Raw rice

Raw rice will give off a rancid odor when it has gone bad because it has fats in it which will deteriorate overtime. Brown rice spoils faster than white rice due to its higher fat content.

Raw rice may also get infested with bugs which you can easily see crawling about in your rice. They appear blackish red in color. Now these bugs can be separated by soaking the rice in water but if you feel uncomfortable with the idea of bugs in your food, then it is better to throw the rice out.

Next, touch the rice. If it feels damp or oily, then it means that the oil in the rice grains has seeped out of them making the rice go bad.

Cooked rice

Cooked rice will also give off a bad smell when it has spoiled. The taste may also alter if it has spoiled. It should taste exactly like the way it did when it was cooked.

Cooked rice should also have a fluffy and airy texture. Spoiled rice, on the other hand, will be slimy and gooey to touch.

Look for any growth of mold or discolorations as well.

Learn more about shelf lives of rice here.

Other FAQs about Rice that you may be interested in.

Does rice have to be refrigerated?

Does rice have fat?

Does rice absorb water?


In this brief guide, we answered the question “What is fried rice syndrome?”, and told you why it happens. We also discussed how to avoid getting fried rice syndrome and how to manage fried rice syndrome. We also mentioned how to tell when rice goes bad.