Can Leftover Rice Lead to Food Poisoning?

Leftovers are the ultimate in convenience, making meal prep feel like a breeze. But while reheating most dishes is no big deal, rice is one food you can't afford to let slide. It’s one of the few exceptions that can cause trouble.

We often overlook the dangers in the kitchen, but rice? That tiny grain may seem harmless, but it can wreak havoc on your digestive system. What might seem like a harmless box of fried rice can lead to food poisoning within 30 minutes to 6 hours, with symptoms so severe that some describe it as the worst foodborne illness they’ve had. You could be stuck in discomfort for anywhere from 24 hours to a whole week. It’s safe to say, avoid it if you can.

Why Does Rice Cause Food Poisoning?

Uncooked rice can contain Bacillus Cereus spores, a harmful bacteria linked to food poisoning. These resilient spores can survive cooking, and if rice is left out at room temperature (especially in the “danger zone” of 40°F to 140°F, with 100°F being especially risky), they can turn into bacteria. The bacteria grow rapidly, producing toxins that make you sick. And unfortunately, these toxins stay even after reheating.

Bacillus Cereus originates in soil, but it can also be found in water, plants, and even the digestive tracts of some animals. Essentially, any grain-based food can harbor it — pasta, noodles, couscous, farro, and others. This food poisoning is often associated with 'fried rice syndrome' because rice is particularly susceptible. Why? Rice grows directly in the soil and undergoes minimal processing before being cooked, unlike wheat products. This means rice may contain higher levels of the bacteria, making it riskier when left out in the temperature danger zone.

How to Avoid Food Poisoning From Leftover Rice

Contrary to common belief, the danger doesn’t lie in reheating rice but rather in how it's stored after cooking.

The key is to refrigerate cooked rice within an hour to prevent bacteria from growing. Speed up the cooling process by spreading the rice out in smaller containers, placing them in ice baths, or laying it flat on trays. If you're in a rush, simply pop the hot rice straight into the fridge.

To store it safely, transfer the rice into shallow dishes and leave the lid off until it cools. Once cooled, cover it and store for up to four days. Unfortunately, rice is not one of those leftovers you can casually eat a week later and assume it's still good.

Other considerations to keep in mind include:

• When you've ordered rice via takeout, be extra aware. You don't know exactly how long it's been sitting out in the first place, i.e., how long it's taken to get to you. Your best bet is to get it into airtight containers and into the fridge as soon as it arrives (after dishing up your current meal, of course), just to ensure it's safe to eat the following day.
• Only ever reheat your rice once. If there are multiple portions, dish up what you're about to eat for reheating and leave the rest in the fridge. Never reheat the whole batch and move the leftovers to the fridge for a second time. 

The Bottom Line

Personally, unless I'm making something like a casserole or a one-pot meal, I prefer to cook just the amount of rice I need for that meal. I’ll prepare extra protein and vegetables for leftovers, but I always make fresh rice each time. Rice is just too easy to cook, and the risk of food poisoning isn't worth it.