How Long Can You Keep Rice in a Rice Cooker?

Rice is a fantastic staple food that goes with just about everything from sushi to curry. Jam-packed with nutritional properties along with energy that can power anyone, child and adult, for their entire day, it’s no surprise that billions feast on rice on a daily basis. Likewise, its simple yet quick cooking process further boosts its popularity. But here’s the problem: we live busy lives and sometimes can forget to properly store our unfinished rice once we’re done eating. Instead of scooping out the remains and storing them in the fridge, rice is left to its own devices in the cooker. This leads us to ask the seminal question: how long can rice be kept in the cooker? 

Unfortunately, there is no one-size-fits-all answer to this. How long it can be kept depends on a variety of factors including what kind of rice you’ve cooked and whether you included anything extra like vinegar. But generally the consensus is this: don’t eat rice that’s been left in the cooker overnight! Unless, you want to fall sick that is.

How long can rice be kept in the cooker if the ‘warm’ setting is used?

Once a batch of rice has been cooked, it should be able to remain in the cooker for a few hours at most if you toggle on the keep warm button (some sources say that 12 hours is the upper limit before you should dump the rice). We personally don’t suggest more than a couple hours. The problem is once rice cools from its cooking temperature, bacteria in the air will begin to work its way to the rice, eventually rendering the rice dangerous to consume.

Think about it: a warm rice cooker that’s moist makes for the perfect breeding ground for nasty bacteria. Even beyond a safety standpoint, rice left in the cooker will also start to dry out and will almost certainly make for an unpleasant eating experience! It’ll even start to taste blander than usual as all of its natural sugars will have been lost. 

However, if your rice cooker does not come with a keep warm setting and you’ve stored your rice overnight in a room with warm ambient temperature, we strongly recommend getting rid of all the rice and that you cook up a new batch for your next meal. 

What are some signs that my rice has gone bad?

Surprisingly, you may find it harder to tell when rice has gone bad compared to other foods such as dairy-based foods. If your rice has been sitting in the cooker for over a day, even if it looks normal and smells normal, we highly suggest you throw it away – spoilage isn’t always obvious here.

On the other hand, if you start to notice odd smells, excessively hard and dry grains, or discoloration, these are telltale signs that your rice has spoilt and is rife with unwanted germs. Rice is unfortunately, thanks to its high starch content, the perfect breeding ground for all kinds of bacteria so to preserve the health of yourself and your household, always be vigilant! 

What’s the ideal way to store my rice after cooking?

Once you’ve finished eating, gather any remaining rice and store them in separate, airtight containers. Before sealing them, do let them cool off for a little while to prevent sogginess and to ensure that they don’t bring up the overall temperature of your fridge. Once done, simply store them in your fridge and reheat them once you’re ready for your next meal. Just make sure that your fridge is at temperatures below 40 degrees F. 

Now to speed up the cooling process and to minimize the time bacteria can develop, we recommend spreading out your leftover rice on a clean tray to ensure it cools as fast as it can. Once cool, immediately transfer your rice to clean, airtight containers and store them in the fridge.

You should be able to store your cooked rice for up to four days following this method though you might find your rice a little harder than normal the next day (tip: using a day’s old rice is perfect for making fried rice)! Now if you’re storing brown rice, you should remember than because of its bran layer, it will not last as long as white rice, both cooked and raw. Assume that they’ll last for up to two days at maximum. 

Will brown rice and vinegar rice last longer than white rice?

Unfortunately, we don’t think so. Brown rice in general because of its bran layer and natural oil content, tends to also come with a shorter lifespan than their white rice counterparts. Likewise, once cooked, you should assume that everything that we’ve said about white rice equally applies to brown rice. 

When it comes to vinegar rice (i.e. the rice you’d use for sushi), there isn’t any general consensus on this yet. While in general, vinegar should have some antibacterial properties, it isn’t perfect as a disinfectant. Disinfectants are only effective if they can kill 99.9% of dangerous bacteria which unfortunately vinegar does not achieve. Likewise, vinegar doesn’t work against all kinds of germs. With this said, we strongly recommend you also assume that whatever applies to white rice also applies to vinegar rice. 

How many times can I reheat my cool rice?

For virtually any type of rice regardless of color, know that you should only reheat it once. Anymore and you’ll risk poisoning your stomach. 

There’s no singular best way to reheat your rice. You can reheat it however you like via the stove, oven, or even microwave. Just ensure that the temperatures you use are high. However on matters of taste, you should add around 2 tablespoons of clean water (you can also use butter or oil depending on your taste) for each cup of rice you reheat. Stored rice tends to dry out so the added moisture will ensure that the rice becomes as fluffy as possible.