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Comment by slillibri | Hacker News Reader

I love my Zojirushi fuzzy logic rice cooker, mainly for the keep-warm. I can put several cups into the cooker and eat off it for several days. Also, yes my cooker has a Scorch setting.

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And don’t forget the value add of it playing Twinkle Twinkle Little Star when the rice is ready. At least that’s what mine does, lol.

Are you sure about that? Mine plays Twinkle Twinkle Little Star when you turn the rice cooker on. It plays a different tune when the rice is ready. ;-)

Hah! Well, point taken :)

However, I have always been told not to keep rice in the rice cooker for days at a time, for health reasons. If it's warm, I'd imagine it's an even better environment for bacterial/spore growth.

I believe it is kept at a high enough temp that bacteria cannot survive.

> However, I have always been told not to keep rice in the rice cooker for days at a time, for health reasons. If it's warm, I'd imagine it's an even better environment for bacterial/spore growth.

IIRC, the reason Zojirushi gives for not keeping rice warm for too long is that it will get yellow and hard. I don't think they mentioned food safety concerns. Mine does have a small vent hole, so I guess the moisture must escape eventually.

An entire continent full of kitchens keeps rice in cookers/warmers for days at a time. There us just no there there.

Watch out for Bacillus cereus

Thanks for that tidbit, I had to look it up. This wiki page (https://en.wikipedia.org/wiki/Bacillus_cereus) says, "Germination and growth generally occur between 10 °C and 50 °C, though some strains can grow at low temperatures". I just measured the rice in my Zojirushi cooker, and it read 70 °C.

But presumably the GP isn't keeping the rice cooker on keep warm for days. All the moisture would be lost. Safer to refrigerate cooked rice.

Whether they are or not: it is absolutely something that is fairly commonly done. Sealed cookers can do it pretty well, the rice is essentially fine for that long (safety aside).

I think that's exactly what GP is doing

Keep warm settings on rice cookers keep the rice above 60C to avoid bacterial or fungal growth.

I use the keep warm setting on a rice cooker for another reason: To make black garlic. Take 20 bulbs of good quality garlic, put it in the rice cooker, set it on "keep warm" (NOT cook!) for two weeks without opening the lid. Note the rice cooker will be useless for anything else after this because you'll never get rid of the ingrained garlic smell.

Do you leave it on 'keep warm' for days?

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