[HN Gopher] The inventor of the automatic rice cooker
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The inventor of the automatic rice cooker
Author : jnord
Score : 71 points
Date : 2024-10-30 09:08 UTC (3 days ago)
(HTM) web link (spectrum.ieee.org)
(TXT) w3m dump (spectrum.ieee.org)
| AStonesThrow wrote:
| Technology Connections covered rice cookers:
| https://youtu.be/RSTNhvDGbYI?si=PxZYi4YYs9nixATv
| JoeDaDude wrote:
| Came here to point folk to this video. The article seems to
| gloss over a lot of how modern rice cookers actually work. It
| involves latent heat of water, magnetism, and the Curie point,
| as explained in your link.
| ChrisClark wrote:
| Always with the latent heat. :)
| ninalanyon wrote:
| Off topic but I can't let this go by:
|
| > yogurt requires a constant temperature over a specific length
| of time.
|
| No it doesn't. I make perfectly good yoghurt in an old glass
| vacuum flask by heating a litre of milk to 80 C, allowing it to
| cool to 50 C, adding 60 g of live yoghurt, pouring it into the
| vacuum flask, putting the lid on and leaving it overnight.
| profsummergig wrote:
| Is it necessary to heat it to 80c, can one heat it to 50c only,
| instead? Also, do you use a thermometer to measure the temps?
| toothrot wrote:
| 80c is a convenient temperature for activating naturally
| occuring enzimes in food for breaking down complex sugars.
| Similar, but food specific, holding temperatures are used for
| beer brewing, french fries, and other foods with complex
| sugars.
| hinkley wrote:
| In fermentation the initial heat is usually to harm any
| microbes other than your preferred ones so the selected
| microbes have time to make the environment inhospitable to
| other microbes before they can do the same to the selected
| microbes.
|
| Vinegar and alcohol in grape juice are two factions fighting
| for supremacy by trying to poison each other to death.
| eru wrote:
| Isn't vinegar made from alcohol? So it's more like an
| assembly line of sugar to alcohol to vinegar?
| perbu wrote:
| Both. They can make acetic acid from both sugar and
| ethanol.
| nsenifty wrote:
| Been making yogurt at home for years. I just heat milk to the
| point when it's just about to boil over. Never measured the
| actual temperature, but I'm pretty sure it's less than 100C.
| I just cool it until it's warm to touch (about 40-45C) before
| adding the culture (a spoonful of last day's yogurt), then
| leave it overnight in the oven with the pilot light on.
| Spooky23 wrote:
| You should follow the guidance and use a candy thermometer to
| kill the nasties.
|
| Once you make a few batches, you can usually eyeball it,
| different milks will act subtly different at temperature.
| Heating also changes how milk components can consumed by the
| cultures. I get milk from a farm that doesn't homogenize it
| the same way as store stuff - the skin develops on the
| surface sooner.
|
| Personally, I prefer to use a yogurt maker that keeps it at a
| consistent temperature. But you can make great yogurt in a
| variety of lower tech scenarios.
| fuzztester wrote:
| yes, and even in a no-tech scenario, as i said here:
|
| https://news.ycombinator.com/item?id=42029736
|
| :)
| dundercoder wrote:
| I find that the yogurt is thicker when I initially heat it
| higher. My understanding is it changes some of the proteins,
| resulting in a higher curd yield.
| fuzztester wrote:
| right, you don't need a constant temperature to make yogurt.
|
| in india, people don't even measure the temperatures as you
| mentioned.
|
| we just boil the milk (to sterilize it), let it cool some
| amount, put in the curd (indian english term for yogurt, dahi
| in hindi, thayir in tamil) starter (which is just curds from a
| previous batch), mix, and leave it covered for a while,
| typically overnight, anywhere in the house, or in a cooler or
| warmer part, depending upon your location and ambient
| temperature. the milk automatically sets, by the action of the
| bacteria, and becomes curd.
|
| nothing to it. even kids can make curd.
| GauntletWizard wrote:
| I loved my automatic rice cooker, but I have given it up for a
| new love - The Pressure Cooker, in my case from Instant Pot. It
| does as good or better of a job as my rice cooker, but about 33%
| faster, and has several other useful functions. It's better at
| steaming dumplings; With the trivet set they also sell that's
| perfectly sized I can make a meal's worth of dumplings in twenty
| minutes with zero effort. The Instant Pot recipe Pulled Pork is
| almost as good as my local BBQ place, and it cooks in an hour.
|
| On the other hand, one of my friends has a Zojirushi rice cooker,
| and swears by it. He describes making perfectly fluffy and
| buttery rice every time.
| ngneer wrote:
| This reads like an ad.
| imp0cat wrote:
| It's true though. Another great thing is that the IP will
| have regular white rice done much faster (~15 minutes for
| perfect rice).
| navigate8310 wrote:
| Zojorushi cookers are definitely the Bentley of rice cookers
| stephenr wrote:
| > He describes making perfectly fluffy and buttery rice
|
| If your rice is buttery I think they're doing something wrong.
| pessimizer wrote:
| What if you want rice with your dumplings or pulled pork...?
| nox101 wrote:
| Japan sells tons of pressure based rice cookers.
|
| https://www.amazon.co.jp/s?k=%E5%9C%A7%E5%8A%9B%E7%82%8A%E9%...
| hilux wrote:
| I enjoyed reading the story, AND for most Americans, an electric
| pressure cooker (e.g. Instant Pot) cooks rice perfectly (12
| minutes, 1:1 ratio of rice to water), rendering the rice cooker
| an unnecessary "single use device."
|
| Bonus: instead of rice, use chicken broth, previously made in the
| IP, and frozen.
|
| Bonus2: add some coconut milk. freeze the rest of the can in
| ziploc baggies.
| itchyjunk wrote:
| Hmm, if I use chicken broth instead of rice, isn't the end
| product just chicken soup instead of a rice dish? :D
| GordonS wrote:
| Not if all the liquid is absorbed. I cook rice like this on
| the stove all the time, and it's really tasty. Works well
| with various grains, pltho probably pearl barley is a
| favourite - cooked with good stock, it reminds me of risotto.
| Frenchgeek wrote:
| If between rice and water, you replace the rice with
| chicken broth, I'm pretty sure you don't get to cook much
| rice...
| Agingcoder wrote:
| If all of it is absorbed, then it's a risotto ( you just need
| onions and white wine as well...)
| walthamstow wrote:
| All absorbed? That's a pilaf, or a terrible risotto.
| internet101010 wrote:
| Yeah I use Instant Pot, sometimes replacing water with broth or
| if I am feeling fancy I'll add some saffron. Good to go.
| hollerith wrote:
| I like to prepare my rice as if were pasta (i.e., tons of
| water, which gets drained and discarded at the end) to reduce
| the arsenic by half.
| ngneer wrote:
| Being a single use device has its benefits. Rice cookers are
| lighter weight than an instant pot and have a single button,
| making them extremely easy to operate. I find this is very
| helpful to me when cooking.
| eru wrote:
| You can get some very fancy rice cookers in Asia, with lots
| of buttons. Some of them really do produce a better end
| result.
| VeejayRampay wrote:
| they really do, perfect rice everytime if you wash when
| necessary and use the proper rice to water ratios
| manbash wrote:
| I sometimes indulge in doing the KFC chicken rice cooker hack
| recipe. Look it up if you haven't yet.
| Dwedit wrote:
| I get bad results when cooking Calrose rice in an Instant pot,
| and much better results when using a rice cooker.
|
| (Rice Cooker calrose recipe: Weigh the rice. 1.1 times the mass
| of the rice is the amount of water you need.)
| mcshicks wrote:
| I use a pot in a pot for 12 minutes and it's ok. I use those
| stacking metal pots you can get at an Indian food market. I
| also have an old rice cooker. The convience of the instant
| pot is I can set a 30 minute delay to soak the rice. The
| newer rice cooker my mother in law has in Japan does the
| delay and has lines on the inside of the non stick pot to
| measure the water so it makes pretty good rice every time.
| hedgehog wrote:
| Pot in a pot also minimizes cleanup, I'm a big fan but few
| people seem to use that method.
| pessimizer wrote:
| What if you're using the instant pot for something else (like
| beans, or maybe the entire rest of your dish) while you're
| cooking rice? A rice cooker is the _best_ single use device
| because 1) you 're probably having rice with 25-100% of your
| meals, and 2) set-it-and-forget-it; you can completely ignore
| it until you're ready to eat.
| fuzztester wrote:
| any downsides to using a rice cooker? never used one before,
| and I am thinking of buying one.
| ngneer wrote:
| This is known as bang-bang control, a very basic form of negative
| feedback.
|
| The key insight, which may not be emphasized enough in the
| article, is that the vessel can only rise to above 100C once all
| the water has changed phase (boiled).
|
| I think this is the same principle explaining why beach popsicle
| vendors can carry many items on a hot summer day without them all
| melting right away. There is insulation, for sure, but in
| addition the temperature of what is effectively a large volume
| ice cube block must rise above 0C before the popsicles can begin
| to change phase (melt).
|
| In the rice cooker, this property is harnessed while a
| "bimetallic switch measured the temperature in the external pot".
| The bimetallic component means that one metal heats and expands
| faster than the other, eventually breaking the circuit.
|
| If memory serves, this same trick is used in older car model turn
| signal lights, to produce the periodic on/off switching.
|
| I am not asian but enjoy my rice cooker every day. I love simple
| robust engineering.
| l33t7332273 wrote:
| I think the popsicle example may be backwards - they must
| change phase before they can begin to rise above 0 degrees, and
| the phase change is a tipping point that takes a ton of energy
| Etheryte wrote:
| The same bimetallic break was used in old circuit breakers. You
| would literally have to wait for the metal to cool down before
| the connection could be restored. Not sure if it's still used
| or we use something fancier these days?
| delsarto wrote:
| My washing machine door works like that; BigClive has a great
| teardown which was quite helpful to explain to me why I
| couldn't open the door!
| https://youtu.be/PIm7q_U3UEM?si=K6wUtHJe2Jm8tW6M
| praptak wrote:
| Modern circuit breakers are much fancier. They break not only
| when the current reaches a threshold but also when the
| currents passing in both directions (i.e. also back through
| the ground wire) are unequal. This prevents things like
| grounding through someone's body.
| schiffern wrote:
| > Modern circuit breakers are much fancier. They break...
| when the currents passing in both directions [is] unequal
|
| What you're describing is properly called GFCI[0] -- which
| in some countries is referred to as an RCD[1] -- not just a
| standard circuit breaker.
|
| You _can_ get devices which fit into a standard circuit
| breaker slot which perform both functions. However a
| conventional circuit breaker (which are still widely
| available) doesn 't do any of that.
|
| [0] Ground Fault Circuit Interruptor
|
| [1] Residual Current Device
| Buttons840 wrote:
| > The bimetallic component means that one metal heats and
| expands faster than the other, eventually breaking the circuit.
|
| I thought the circuit that powers the cooking was broken
| because, when the water has boiled away, heat rises and a
| magnet holding the circuit closed is weakened by the heat,
| which allows a spring to pull the magnet away and break the
| heating circuit. (Magnets are weaker when hot.)
| dmoy wrote:
| Thermostats also used to use the bimetal trick
| fallinditch wrote:
| Using a rice cooker is not the healthiest method due to the
| arsenic and other carcinogenic substance that rice plants can
| contain.
|
| Dr Michael Mosley studied the science of this for his BBC program
| Trust Me I'm A Doctor [1]. The advice is to soak rice overnight,
| parboil and discard the water, change water and bring back to
| boil again and change water again, etc.
|
| [1]
| https://www.bbc.co.uk/programmes/articles/2F1MDzyW55pg97Tdpp...
| tomohelix wrote:
| It is funny to me that any time an article or claims regarding
| rice being unhealthy appear, it would be from some far West
| country whose diet barely contains any rice. Meanwhile, Asian
| countries whose populace exclusively eat rice every day,
| multiple times, in humongous amounts, consistently rank higher
| in life expectancy than a Western country with the same level
| of development.
|
| I am not saying rice is the only reason. My point is if rice is
| so bad, we would not see Japan or Korea or Singapore dominate
| the life expectancy charts. Compared to the extremely greasy
| and highly processed food being sold widely in the US for
| example, rice is extremely healthy.
| hedgehog wrote:
| Arsenic content is also highly variable depending on where
| the rice was grown.
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