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I'm trying to figure out a convenient way to bring fresh rice for lunch. Cooking it the night before and leaving it in the fridge causes it to become dry and hard and unpleasant, and I've read that it's not safe to leave cooked rice out at room temperatures for long periods of time (such as overnight).

So I thought it would be nice if I could at least save myself the trouble of having to wash it in the morning. Would it be safe to wash it the night before, and cook it in the morning? If so, what storage methods should I use? Just leave it out on the countertop? Or should I leave it soaking in water? Or either dry or soaking in an air-tight container? Or should it be refrigerated? I'd also like to hear any methods anybody else has for having fresh rice at lunch!

I should mention I'm referring to short grain Japanese white rice. Thanks!

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  • Sounds like a recipe for mold to me, unless you have a means of drying it very thoroughly. Also have a look at our friend B.cereus, the critter responsible for "fried rice syndrome". The only reason these things don't grow on rice while it's in storage is because it's dry.
    – Aaronut
    Jan 14, 2014 at 1:00
  • You think it would cause an issue if left uncooked, merely washed and perhaps sitting in water, for no more than the 8 hours it takes me to sleep? And actually, that brings up a good side question: When is it safe to stick in the fridge? I know (or am under the impression) that sticking things that are still warm in the fridge is bad. But if it's dangerous to leave cooked rice out..? Or does the problem come from leaving cooked rice in a warmer environment than you'd have at room temp waiting for it to cool to refrigerate?
    – Fulluphigh
    Jan 14, 2014 at 2:49
  • Hot food in the fridge is pretty much fine: cooking.stackexchange.com/questions/8919/… (there's some disagreement there, but the summary is the worst that it can do is make your fridge work harder, and heat up what you put it next to).
    – Cascabel
    Jan 14, 2014 at 2:57
  • Leaving it at room temperature: generally, if you're worried about bacteria growing, 2-4 hours without refrigeration is enough to have potential worries. I'm not sure exactly how fast this particular bacteria grows, but I certainly wouldn't assume it's safe.
    – Cascabel
    Jan 14, 2014 at 2:59
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    @Fulluphigh Putting a large container of food straight in the fridge is a problem because it won't cool quick enough. E.g., if you throw a stockpot full of stock in the fridge, it'll take many hours to cool—you need to divide it into smaller containers or use an ice wand or bath to cool it. I suspect that's what you heard Ramsay complain about.
    – derobert
    Jan 14, 2014 at 19:21

2 Answers 2

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I did this in my restaurant for years, it really does work great. Make your rice in a huge batch, cook it as if you're planning to eat it then, but then let it cool until handlable. Once it is cool enough, bag it in individual servings and freeze it. Refrigerating cooked rice quickly ruins it, freezing it, however, works great. If your servings are fairly small, snack sized ziplocks work great for this, otherwise use sandwich sized. Make sure you press the air of the bags, I take all of the small bags and seal them together in gallon sized ziplocks to give them one more layer of protection in the freezer. Either with the rice solidly frozen, or at lunchtime (defrosted, cool rice), throw the baggie in the microwave. You don't even have to open the baggie, when it pops open that's a sign to check it. It may need a bit of a mix and a few more seconds in the microwave, or it may be done, it just needs to be heated through. The hot rice will be almost indistinguishable from freshly cooked. If you don't have a microwave, you can drop the sealed baggie into simmering water, or take the frozen or cool rice out of the bag and steam it to heat.

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  • I would never have thought that freezing would work better than refrigerating =o I'll definitely give this a shot.
    – Fulluphigh
    Jan 14, 2014 at 2:55
  • @Fulluphigh I'm glad to hear that. It really is a great solution to an age old problem.
    – Jolenealaska
    Jan 14, 2014 at 2:56
  • I boil rice, then immediately rinse it under a cold tap to wash off the starch and chill it down quickly, then straight into the fridge, in an airtight container. If it's cooled quickly, there is no time for bacteria to form before it's in the fridge and it reheats really quickly. I only use basmati rice, so I can't comment on the Japanese type. Jan 14, 2014 at 16:13
  • I had intended to experiment with this before marking it as the answer, and then forgot about it, haha. I suppose this isn't a direct answer the the question I asked, but it is a superb solution to my actual problem!
    – Fulluphigh
    May 30, 2014 at 18:01
  • @Fulluphigh Does that mean you've done it? You're right that my answer doesn't really address the question in your title, but it does address the question in the text, particularly the first paragraph :)
    – Jolenealaska
    May 30, 2014 at 22:21
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My understanding from now far-in-my-past food safety courses is that uncooked rice does not have the same risk of bacterial growth even if soaked in water at room temperature. However, after about 24 hours, it does start to do things that are reminiscent of sprouting (though white rice won't actually sprout), including grassy aromas.

Most Japanese families with automatic rice cookers who eat rice in the morning place washed rice in their rice cooker with the appropriate amount of water and set a timer. I doubt there are frequent occurrences of food-borne illness directly attributable to this method, but cooked rice left in the danger zone is known to be a great breeding ground for unpleasant micro-critters.

Typically the soaking time used in these situations is 6-12 hours.

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    I see, interesting. I hadn't considered the rice actually doing anything like sprouting =P I have read that cooked rice left at room temp is a bad idea, and obviously keeping it in the fridge makes it dried and bleh. I wish I had a rice cooker with a timer, but it's not a worthwhile investment for me at the moment. I suppose it's pretty unlikely to hurt me then. On the other hand, would keeping it warm in an insulated container for the ~4 hours between cooking and lunch pose an issue?
    – Fulluphigh
    Jan 14, 2014 at 2:51
  • @Fulluphigh if your insulated container can keep it above 140°F, then you're definitely OK—you can hold food at 140°F (actually 131°F but 140 gives a safety margin) forever. Well, from a safety standpoint; quality is an entirely different matter.
    – derobert
    Jan 14, 2014 at 19:25

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