Do you like to eat rice? Do you sometimes keep it in the fridge and eat it later? Me too! These are very common, relevant things about us. Unfortunately, there has been a small panic on social media lately, worrying about how dangerous it is to eat rice for a few days. These warnings are somewhat exaggerated, but there is some truth to them (ha!). ）。
I will start with the conclusion, and then we can understand why this is the case. Those who say never save leftovers, or those who imply that reheated rice can easily kill you, are either misleading themselves or overexaggerating.
As long as the reheated rice doesn't stay in the danger zone for too long, you can safely eat it. The danger zone is 40 to 140 degrees Fahrenheit, which is warmer than the refrigerator but lower than the cooking temperature. Two hours is considered a safe time limit, and honestly, you should follow this rule for all cooked perishable foods.
If your rice gets from the rice cooker (or stovetop) to the fridge during this time, then you won't be taking any huge risks. This way your rice will last for days, just like your other leftovers. But if you are used to leaving rice on the counter for hours while eating dinner, cleaning up, distractions, ......Oh, how long has that been? And then, yes, you should throw away that rice.
All food poisoning is caused by microorganisms such as bacteria or the toxins they produce. While there are many different bacteria that can grow on rice, the most worrying is Bacillus cereus (Bacillus cereus for short). By the way, this is the "waxy" in "cereals" - although it lives in the soil and can be found in almost any food, it is best known for being found in cereals such as rice.
Like any bacteria, Bacillus cereus can exist in the form of bacterial cells that live on nutrients and moisture from food. So far, nothing special. But Bacillus cereus is one of the few spores-producing foodborne bacteria, and you can think of them as eggs that contain the next generation. The spores are heat-resistant, so if you kill the adult worms by cooking the food, the spores will still be there. In fact, the cooling process after cooking prompts them to sprout, so they start growing immediately.
When Bacillus cereus grows, they produce so-called emetic toxins: a toxin that makes people vomit. This toxin is responsible for the so-called "fried rice syndrome" or "rehot rice syndrome", which people blame on leftovers.
To recap, the main difference between Bacillus cereus and most other food poisoning bacteria is that heat does not destroy the toxins that cause vomiting. Usually, if you reheat leftovers to 165 degrees (or "until steaming" or "until piping hot"), you're good to go. Bacillus cereus will laugh in the face of a good microwave. The way to prevent Bacillus cereus from making you sick is to stop it from growing, not letting it grow, and then remember to kill it.
Food poisoning caused by Bacillus cereus in leftover rice may make you vomit, but it is unlikely to have more serious consequences. Typical Bacillus cereus vomiting lasts less than 24 hours and is accompanied by nausea, vomiting, and stomach cramps. It's not fun, and I don't recommend it. But the dire warnings about how leftover rice can lead to people being hospitalized are somewhat exaggerated.
Bacillus cereus can cause two forms of food poisoning: one caused by rice and starchy foods, which we are talking about here; The other is diarrhea, which is more commonly seen in meat, vegetables, and dairy products.
All things considered, the Centers for Disease Control and Prevention estimates that between 2000 and 2008, there were an average of 63,000 cases of Bacillus cereus food poisoning each year, with 20 hospitalizations** and 0 deaths. As a result, one-third of 1% of cases require hospitalization**, but no one dies. This doesn't mean death is impossible, it's just that TikTok's dire warnings are missing a lot of perspective.
Bacillus cereus can cause severe illness and death, but it does not exist in a foodborne form. The National Institutes of Health (NIH) provides physicians with a publication describing the different types of Bacillus cereus infections and their complications and risk factors. Adverse cases have been linked to trauma, intravenous drug use, and bacteria infected with medical devices such as central venous catheters and pacemakers. (Keep in mind that this is a common soil bacterium, so people get the disease through infected wounds.) Bacillus cereus infections are related to the eyes, or start in the eyes and then spread to other parts of the body. body, these often occur after an eye injury. Medically significant: Yes. Refrigerated rice waiting for you in a bowl: None.
We've mentioned earlier that it's safe to reheat (or eat cold) rice as long as it's handled properly in the first place. Let's take a look at the details.
By the way: while I'd love to be your go-to for understanding the science behind the rumors you may hear online**, keep in mind that the USDA has a wealth of food safety resources online, as do many agencies' collaborative extensions. University. These are all better than TikTok, blogging, or even the main **better**. Food safety professionals understand these because it's their job.
Let's take a look at the publication published by the USDA and the University of Florida Institute of Food and Agricultural Sciences on the prevention of foodborne illness caused by Bacillus cereus. Did it say to throw away your rice? No! It says:
Heating (i.e., cooking) to 145°F (63°C) and reheating to 165°F (74°C) for 15 seconds will disrupt vegetative (actively growing) cells.They don't give a specific length of time that counts as "quick" cooling, but elsewhere they cite regulations that stipulate that food should not be left out for more than two hours.Once cooked, the rapid cooling of the product will prevent any of the spores present from germinating. However, please note that food is not safe to eat if toxins have been formed.
Keep hot foods above 57°C (135°F) and cold foods below 5°C (41°F) to prevent the formation of spores. Refrigerate leftovers properly by cooling quickly to 41°F (5°C) or lower. Make sure the remaining containers are not stacked on top of each other; This will allow enough airflow around the food and ensure rapid cooling.
The "warm" setting of a rice cooker is usually around 150 degrees Fahrenheit, which means that, as disgusting as it may seem, it may be okay to eat rice that has been sitting in it for hours. But if you do this regularly, you may want to use a thermometer to make sure that the rice cooker actually keeps the rice hot enough to stay out of the danger zone.
How long can rice be stored in the fridge if handled properly at first? There is no specific recommendation for rice here, but for general cooked food, it is limited to 7 days if it is consistently below 41 degrees. (Your fridge temperature should be well below 41 degrees, both to keep the food safe and because the colder the food, the longer it lasts.) Since 32 degrees is already icing, anywhere is perfect around 30 degrees. The 7-day guidelines apply to establishments such as restaurants; The recommendation for the general public is three to four days, which is three to four days.
For reasons I don't quite understand, *** from the UK such as the message from the NHS) tends to recommend that the rice be stored in the fridge for no more than a day. But American sources agree with the University of Florida. A food safety expert at the University of Wisconsin-Madison says properly handled leftover rice can last for three to five days (noting that cold rice salad is one of her favorite lunches). The University of California, in their own rice safety publication, agrees, also recommending three to five days. I would stick to their advice, not TikTok's, and continue to eat the leftover rice.