Rice is more problematic than some other leftover foods as it may contain bacteria called Bacillus cereus, which survive some cooking processes.
This bacterium is often the cause of food poisoning from reheated or cooked rice. Food poisoning usually causes diarrhea and vomiting and can cause severe complications in people with other health issues.
If people do not follow food safety guidelines correctly, the bacteria may grow on leftover rice and make people sick. However, handling food correctly can prevent illness.
How to prepare, store, and reheat rice safely
If a person follows food safety guidelines, they can reheat rice without risk.
The United States Department of Agriculture (USDA) outline the safest ways to cook, store, and reheat food, including rice, properly.
Each of the following steps will ensure that reheated rice has a low risk of making people sick:
1. Wash hands well
Always wash hands thoroughly before preparing and cooking food. Keep utensils that have touched raw animal products separate.
2. Cook the rice properly
Serve rice immediately after cooking.
3. Cool the leftovers quickly
To further reduce bacteria growth, cool food quickly by:
- Dividing the food into shallow food containers and sealing them with a lid.
- Placing hot food directly into the fridge or freezer. Risottos or paellas will freeze better than plain rice.
- Do not leave rice or any hot food sitting out for more than 1 hour.
4. Store leftovers properly
The USDA recommend only storing leftovers for set periods:
- Dispose of fridge leftovers after 3 to 4 days.
- Dispose of freezer leftovers after 3 to 4 months.
Store foods at a safe temperature. According to the USDA, room temperature is 90°F, which is the ideal temperature for bacteria to grow. Bacteria grow rapidly between 40°F and 140°F.
- Store foods at 40°F and below. Make sure the fridge is at this temperature or lower.
- Throw away any leftovers kept at room temperature for over 2 hours.
When reheating rice, make sure it is piping hot throughout.
To microwave leftover rice:
- Open the storage container and remove the lid. For each cup of rice, add 1–2 tablespoons of water. Place the lid lightly back on top to allow the rice to re-steam.
- Place in the microwave and heat for 3–4 minutes, or until piping hot throughout.
- Make sure the internal temperature of the rice is at 165°F or higher. If unsure, use a food thermometer.
- Serve immediately.
To stir-fry leftover rice:
- Place the rice in a wok or sauté pan with your choice of oil.
- Turn the stove to medium heat, stirring the rice continuously. Make sure to break up the clumps of rice.
- Stir continuously to cover the rice evenly in oil.
- Use a thermometer to make sure internal temperature is at least 165°F.
- Serve immediately when piping hot.
To steam leftover rice:
- Place the rice in a saucepan with 1–2 tablespoons of butter or oil.
- Add 1–2 tablespoons of water for each cup of rice and bring to a simmer. Keep the lid on the saucepan.
- Stir occasionally. Once the water has boiled off, check that the internal temperature is above 165°F.
- Serve immediately if piping hot.
It is safe to eat the rice cold as long as it has been cooled and stored correctly. Do not leave reheated rice sitting on the counter.
Following these steps will reduce the risk of food poisoning. Do not reheat the rice more than once as this further increase the risk of food poisoning.
Early symptoms of food poisoning
Abdominal pain can be a symptom of food poisoning.
Food poisoning symptoms typically include:
- abdominal pain
The symptoms will come on quickly and should only last a short time. According to one report, there may be up to 84,000 cases of food poisoning caused by Bacillus cereus each year in the U.S.
Most people will recover quickly with no complications. Speak to a doctor if:
- symptoms persist longer than 48 hours
- symptoms worsen
- new symptoms appear
Reheating rice is safe when done correctly. It is essential to practice food safety and hygiene whenever cooking.
Following specific steps will reduce bacteria growth and limit the risk of food poisoning from eating reheated rice.