Yes, uncooked rice can make you sick. Raw rice commonly carries spores of a bacterium called Bacillus cereus, which can cause food poisoning. Eating raw, dry rice also poses digestive and dental risks on its own. But the most common way rice causes illness isn’t from eating it raw. It’s from cooking rice, leaving it out too long, and then eating it later.
The Bacterium That Lives in Rice
Bacillus cereus is a spore-forming bacterium found naturally in soil, and it frequently ends up on grains like rice. What makes it unusual is that these spores are extremely tough. They survive boiling, microwaving, and frying. In small numbers, the spores are harmless. The problem starts when they’re given the right conditions to multiply.
When cooked rice sits at room temperature, the spores wake up, begin reproducing, and release toxins. Rice is especially hospitable because each grain is tiny, creating a large total surface area with more places for bacteria to grow. The CDC estimates B. cereus causes roughly 63,400 cases of food poisoning per year in the United States.
Two Types of Illness, Two Timelines
B. cereus produces two different kinds of toxins, and each causes a distinct illness.
The emetic (vomiting) type hits fast. Nausea and vomiting begin within 30 minutes to 6 hours of eating contaminated rice or starchy foods. This form is caused by a toxin called cereulide, which is heat-resistant, meaning reheating your leftovers won’t destroy it once it’s been produced.
The diarrheal type takes longer to appear, usually 6 to 15 hours after eating. It causes watery diarrhea, abdominal cramps, and pain. Nausea and vomiting are uncommon with this form. Both types are typically self-limiting, with symptoms resolving within 24 hours. Hospitalizations are rare but do occur, with the CDC recording about 20 per year in the U.S.
Why “Fried Rice Syndrome” Got Its Name
This illness is sometimes called “fried rice syndrome” because the way people traditionally make fried rice creates ideal conditions for B. cereus. The typical process involves cooking a batch of rice, leaving it on the counter to cool (sometimes for hours), then frying it later. During that time at room temperature, the spores multiply and produce toxins. Even when the rice is stir-fried at high heat afterward, the toxins survive.
The same thing happens with pasta salads, leftover rice dishes, and any starchy food that sits out too long before being refrigerated. The cooking itself isn’t the problem. The gap between cooking and refrigerating is.
Risks of Eating Raw, Dry Rice
Some people eat small amounts of uncooked rice as a habit or craving (sometimes linked to a condition called pica). Dry, raw rice poses its own set of problems beyond bacteria. It contains lectins, proteins that can irritate the lining of your digestive tract and interfere with nutrient absorption. Raw rice is also very hard to digest, which can cause bloating, stomach pain, and cramping.
Chewing uncooked grains can crack or chip teeth over time. There’s also potential exposure to heavy metals like arsenic, which concentrates in rice and is more bioavailable when the grain hasn’t been cooked and rinsed. Children and pregnant women face higher risks from all of these effects.
How to Store Rice Safely
The key rule is simple: don’t leave cooked rice at room temperature for more than two hours. If the room is above 90°F, that window shrinks to one hour. Bacteria multiply fastest in the “danger zone” between 40°F and 140°F, and room temperature sits right in the middle of that range.
To cool rice quickly, spread it in a shallow container rather than leaving it in a deep pot. Get it into the refrigerator (at or below 40°F) within that two-hour window. When reheating, bring it to steaming hot throughout. But remember: reheating kills living bacteria, not the toxins they’ve already produced. If the rice sat out too long before refrigerating, no amount of reheating will make it safe.
For uncooked rice, store it in a cool, dry place. Wash your hands before handling food, and rinse rice before cooking to reduce surface contaminants. These steps won’t eliminate B. cereus spores entirely, but they keep the numbers low enough that your body handles them without trouble.