The battle to invent the automatic rice cooker • Hacker News Board

Re: The battle to invent the automatic rice cooker

#81

Post by kijin » Sat, Aug 01, 2020, 3:43 PM UTC

Torkel wrote: post #70

cycrutchfield wrote: post #16

Earlier quoted context omitted.

IMO the Korean brands are the market leaders. Check out Cuckoo

We have a cuckoo rice cooker in Sweden (purchased in Korea). It is great! Our cuckoo is a preassure cooker, and the rice it makes is the best I’ve had. We currently live in Tokyo, and the Panasonic we got here is not as good as the cuckoo. Maybe because the power here is weaker?

The Japanese Kamado referred to in the article is related to Korean Gamasot [1][2], with one crucial difference. The Korean version has a heavy, close-fitting, holeless iron lid that helps maintain a higher-than-atmospheric pressure inside the cooking vessel.

Higher pressure = higher boiling point = higher cooking temperature = different taste.

Korean rice cookers modeled after the Gamasot are basically autoclaves. The good ones maintain a pressure of about 2 atm and a cooking temperature of 120C. Unpressurized rice cookers are more common in Japan, and Japanese people are more used to the texture of rice cooked at 100C. Your sushi probably won't taste right if you cook the rice at 120C.

[1] https://en.wikipedia.org/wiki/Kamado

[2] https://en.wikipedia.org/wiki/Gamasot

Re: The battle to invent the automatic rice cooker

#82

Post by yissp » Sat, Aug 01, 2020, 4:00 PM UTC

gbear605 wrote: post #78

throw0101a wrote: post #68

Earlier quoted context omitted.

> When the water is gone the temperature of the pot starts to rise. Water-to-rice ratios are important. America's Test Kitchen has a good video on the topic, especially if you're using a pot and not a rice cooker: * https://www.youtube.com/watch?v=JOOSikanIlI * https://www.youtube.com/watch?v=DJFU7ezipbg The rice actually only 'needs' a 1:1 ratio, but you need to put in extra to deal with evaporation; brown rice need…

The traditional method in a lot of Asia (per what I’ve read online) is to put a finger on top of the rice pointing down, so that your fingernail is touching the rice, and to fill water up to your knuckle.

Wouldn't this result in different amounts of water depending on the dimensions of the pot?

Re: The battle to invent the automatic rice cooker

#83

Post by blntechie » Sat, Aug 01, 2020, 4:10 PM UTC

Electric rice cookers are pretty uncommon in South Asian countries. Reasons could have been due to the electricity availability and affordability initially.

But it has not caught on even now. I have seen electric rice cookers in minuscule number of households. Based on interactions, it’s more to do with people not liking the taste of the cooked rice. I always found this funny as older generation used to complain about the same about pressure cooked and stove top cooked rice instead of the wood fired stove cooked rice but everyone have accepted it now.

Re: The battle to invent the automatic rice cooker

#84

Post by MHordecki » Sat, Aug 01, 2020, 4:10 PM UTC

ginko wrote: post #56

ffggvv wrote: post #45

Earlier quoted context omitted.

i’m no rice expert but i really don’t think you need a special cooker for brown rice in my experience. just a different ratio of water to rice. it isn’t special

Brown rice takes significantly longer to cook, so the rice cooker might not be programmed to do that.

Why would the rice cooker need to be programmed for it, though? For any given quantity of rice, the two variables during cooking is the amount of water and the power of the heating element[1].

It is known that brown rice requires a different ratio of water, but this is something that can be replicated with any method. Does the special brown rice setting change the heat output of the rice cooker?

[1]: Fancy rice cookers use non-constant power, or so I've heard. Not sure how much it influences the taste, though.

Re: The battle to invent the automatic rice cooker

#85

Post by tzs » Sat, Aug 01, 2020, 4:31 PM UTC

yissp wrote: post #82

gbear605 wrote: post #78

Earlier quoted context omitted.

The traditional method in a lot of Asia (per what I’ve read online) is to put a finger on top of the rice pointing down, so that your fingernail is touching the rice, and to fill water up to your knuckle.

Wouldn't this result in different amounts of water depending on the dimensions of the pot?

Evaporation rate should be proportional to surface area, so the volume of extra water you need to add to make up for that should also be proportional to the surface area too. Adding extra water to a fixed depth accomplishes that.

This is assuming a pot with straight sides, at least above the lowest water level during cooking.

Re: The battle to invent the automatic rice cooker

#86

Post by throwaway_pdp09 » Sat, Aug 01, 2020, 4:37 PM UTC

jrootabega wrote: post #31

spaceflunky wrote: post #14

The science behind a rice cooker is fascinatingly clever, yet painfully simple. In short, boiling water temperature plateaus due to the latent heat of vaporization. When the water is gone the temperature of the pot starts to rise. The rice cooker uses this principle to control the switch. The switch is held by magnet. When the pot finishes boiling the heat rises and exceeds the curie point of the magnet, which means…

It's not the magnet's curie point; it's the curie point of the metal the magnet sticks to. And I guess it's not really the curie point, just the point where the force becomes weaker than the spring

That sounds wrong. From wiki "In physics and materials science, the Curie temperature (TC), or Curie point, is the temperature above which certain materials lose their permanent magnetic properties". What you're saying is that metals stop being attracted to magnets above a certain, rather low temperature. Possible but very hard for me to imagine.

Re: The battle to invent the automatic rice cooker

#87

Post by wil421 » Sat, Aug 01, 2020, 4:39 PM UTC

Bayart wrote: post #34

ThePhysicist wrote: post #10

For people that regularly eat rice, buying a decent rice cooker is really a no-brainer. Cooking rice in a pan is possible and you can obtain good results if you're careful and turn the heat down at the right moment before the rice starts to stick to the bottom of the pan and burn, it's easy to miss though. A rice cooker makes this process so much easier though: Put in the rice, the adequate amount of water, press a b…

>Zojirushi seems to be the market leader these days They also make the best insulated bottles. It's completely besides the point but I felt compelled to talk about it, a good bottle is a game changer when you're drinking tea or coffee at your desk all day long.

I appreciate the comment and I’ll look into one.

Re: The battle to invent the automatic rice cooker

#88

Post by rootsudo » Sat, Aug 01, 2020, 4:40 PM UTC

ThePhysicist wrote: post #10

For people that regularly eat rice, buying a decent rice cooker is really a no-brainer. Cooking rice in a pan is possible and you can obtain good results if you're careful and turn the heat down at the right moment before the rice starts to stick to the bottom of the pan and burn, it's easy to miss though. A rice cooker makes this process so much easier though: Put in the rice, the adequate amount of water, press a b…

Xiaomi rice cooker is the best, I own a few and it really is great. The pot is not thin steel.

I miss my old Panasonic copper rice cooker that I had in Japan. :( Gave it away.

Re: The battle to invent the automatic rice cooker

#89

Post by amluto » Sat, Aug 01, 2020, 4:50 PM UTC

throwaway_pdp09 wrote: post #86

jrootabega wrote: post #31

Earlier quoted context omitted.

It's not the magnet's curie point; it's the curie point of the metal the magnet sticks to. And I guess it's not really the curie point, just the point where the force becomes weaker than the spring

That sounds wrong. From wiki "In physics and materials science, the Curie temperature (TC), or Curie point, is the temperature above which certain materials lose their permanent magnetic properties". What you're saying is that metals stop being attracted to magnets above a certain, rather low temperature. Possible but very hard for me to imagine.

If you take a permanent magnet, heat it above the Curie point, then cool it again, it’s no longer magnetized. So you would have a one-use rice cooker.

Magnets stick well to ferromagnetic materials. If you heat a ferromagnetic object, e.g. a piece of steel, above Tc, it stops being a ferromagnet and magnets will stick to it much less firmly. And, when you cool it, it will once again be ferromagnetic.

Re: The battle to invent the automatic rice cooker

#90

Post by zeroimpl » Sat, Aug 01, 2020, 4:52 PM UTC

grenoire wrote: post #53

I don't quite get why people think that pot rice on the stove is somehow difficult. Measure your rice and water, and set up a timer. That's it. We've been cooking rice for millennia in this way, a rice cooker is just plastic waste in the end.

100%. The proper measuring of ingredients and timing is all that's required.

Take a look at the first line of the article:

    Cooking rice on a stovetop can be fraught. Add too much water and you end up with porridge.

Then take a look at this line shortly afterwards:

    These devices can seem all-knowing. So long as you add water and rice in the right proportions, it’s nearly impossible to mess up

So in other words, the device doesn't actually solve the most important problem... The timing isn't particularly important, as long as you remember to turn down the heat as soon as it starts boiling.