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The inventor of the automatic rice cooker (ieee.org)
240 points by jnord 31 days ago | hide | past | favorite | 214 comments



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.


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


If they used dry ice, you would have 3-ish phase changes...

2-ish phase changes when dry ice sublimates, then later for the ice in ice cream


Interesting tidbit: It was Sony who actually tried to build the first rice cooker, but they failed so badly that they gave up and pivoted to radios [0]

[0] https://onefromnippon.com/rice-cookers/


One thing this article completely glossed over is that most rice cookers you find these days don't have an outer water reservoir that boils away like the one described in the article (until reading this I thought of those as "Taiwanese style rice cookers" because the only ones I had seen like this were from Taiwan).

There is a difference between waiting for one cup in the outer reservoir to boil completely away for 20 minutes, and waiting for the rice+water mixture to come to a certain temperature.

Edit: I ended up down a rabbit hole about why Taiwanese rice cookers more commonly use indirect heat and found this great article:

https://www.taiwangazette.org/news/2021/10/23/thinking-outsi...


Interesting, so in Taiwan at 110V a Tatung won't have the lid rattle around like mine does at 115-120V in the US?


Tatung even makes rice cookers with stainless steel bowls!


For those in the U.S., Aroma and Elite also make stainless steel inner pots.


That's what I use.


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?


Bimetallic strips are still used these days, but it is often not the only trigger.

The bimetallic strip is for overcurrent protection over a period of time. For example, if you are running an appliance using a constant 15A on a 10A breaker. The breaker will pop, but not instantly, and I guess you may have to wait a bit for the metal to cool down, though it never happened to me.

But there is also a short-circuit protection, it uses a solenoid to quickly trip the breaker when the current is way over its rating. The fancier types (with GFCI) also pop if the return current is not the same as the input current, this is to prevent electrocution.


It'll trip if you're drawing 10a sustained, you really can only draw 80% sustained to avoid a nuisance trip.


Looking at the curves published here[1], no breaker should trip with a current draw under its rating, the tolerance goes the other way. For example, after 1h, at 30°C, a breaker should not trip if the current is less than 113% of its rating, and it should trip if it is more than 145%.

[1] https://www.tekdok.dk/files/CA908024E_Trip_curve_2021.pdf


Interesting, I've certainly had nuisance trips at <100% looking at https://www.ece.uprm.edu/~lorama/Square%20D%20CB%20Curves.pd... page 36 you can see even at the rated 25c ambient it goes below 1 (though not as low as 0.9, much less 0.8 rule of thumb).

I haven't given it a lot of research because NEC requires 125% (1/.8) for continuous loads (for conductor protection).

Perhaps my experience was hot ambient/panel.


This depends on the country you're in. As far as I understand breakers here are rated for 100% the rating they are labeled as.


Fun fact, breakers get more sensitive during heat waves. Annoying when it happens.


Maybe it is an unintended but actually beneficial effect.

The problem with drawing too much current is that things can overheat, and it is more of a problem during heat waves as well.


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


Here's that same YouTube link, but without the tracking parameter linking you to everyone who clicks on it:

https://youtu.be/PIm7q_U3UEM


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.


  > 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


In fact in the US, especially residential, GFCI circuit breakers are not terribly common for 120V circuits, people much prefer and are used to having the GFCI in the outlet, which can of course protect multiple conventional outlets downstream.

But, what is quite common in the last 30 years are AFCIs, arc fault interruptors which are code for pretty much all living area branch circuits (just not bathrooms). These are built in to the circuit breaker. You can get dual GFCI/AFCI breakers, but these tend to be expensive and not commonly used. Nobody wants to have go down to the basement just because of a ground fault in the kitchen. Also the propensity for GFCIs to nuisance trip increases with the length of the branch circuit. There’s also cases where they are specifically disallowed.


GFCI outlets also seem to wear out eventually, whether they trip a bunch or not. Lately everyone I know that's sold a house has had to replace one or more of them due to them failing to work during inspections.

Part of the issue with "not terribly common" is that no one ever retrofits these things into older houses and new houses only get them where code requires it since it's an increased cost.


When I mentioned not terribly common I was speaking specifically of GFCI breakers in the breaker panel box as opposed to GFCI in the receptacle. Even in a retrofit or remodel it isn't common to put GFCI in the panel box for the reasons noted. There aren't 240V receptacles widely available with GFCI so these tend to use the breakers.

They should of course be added to any kitchens or bathrooms. It's cheap insurance.


You can get devices which fit into a standard circuit breaker slot which perform both functions

in the UK such a device is called an "RCBO" aka "Residual Current Breaker with Over-Current (protection)"

good summary here from schneider

https://eshop.se.com/in/blog/post/what-is-the-difference-bet...


Yep I thought my house has that until I tested cheap LED dome light from Aliexpress. It had an exposed screw and I was bare feet in garage (concrete floor). Lesson learned.


> (i.e. also back through the ground wire) are unequal.

You mean neutral or return wire. No current should be normally passing through the ground wire. In fact in the US at least, GFCIs can be used on grandfathered ungrounded outlets. When you buy GFCI outlets they come with little stickers: “No Equipment Ground” to affix on the outlet in that case.


They're still built that way: it has the benefit of properly handling slightly over current for a short period vs massively over-current: the former is permitted and necessary for many loads.


My late model Subaru uses this cheap solution for the protection of the infotainment system. If it trips I need to wait for it to cool down for about an hour.


I assume electric water kettles as well, which shutoff shortly after the water starts boiling.


> 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.)


I'm getting multiple downvotes here. Am I wrong? What am I missing?


No idea. You are correct - that's exactly how many rice cookers work.

Technology Connections: https://youtu.be/RSTNhvDGbYI


I came to post this video! But I think it's clear that this isn't the design being describe in the original article: that mentions a double-boiler, which is not in evidence here and TC even mentions the double-boiler aspect of earlier designs at around 9:30 in the video. He also says that he was only able to trace the origin of this design back to the '70s.

So it's possible that earlier designs didn't use magnetism, and the magnet-based design was a simplification of earlier water-boiling-at-100c-based designs.


> I'm getting multiple downvotes here. Am I wrong? What am I missing?

I wouldn't have downvoted you for it, but it sounds like you missed this from the article:

> While the rice cooked in the inset pot, a bimetallic switch measured the temperature in the external pot.

While more modern rice cookers may use curie point magnetic switches, that's not what the original rice cooker used.


The user did not "miss this". They've reacted to it by saying that they have thought rice cookers work differently. Which indeed many of them do.


They replied to a comment about the bimetalic switch in this cooker with "I thought the circuit that powers the cooking was …".

While both you and they are correct that more modern devices work that way, that's not how this one works.

It's possible that they didn't miss that fact, but their comment reads as being a direct response to the discussion of the control circuit of the first rice cooker.


What’s with so many Asian rice cookers advertising “fuzzy logic” and now “neuro fuzzy logic”? Is that just a meaningless buzzword? Or is it something actually useful?


Both. Almost everything today uses some form of it. I think the term stuck with rice cookers because they were advertised that way as an advancement from the binary type cooker described in the article. In that sense, it's a buzzword of sorts. There's a lot of examples of that, like it still being called Unleaded Gas despite it having been so by default for how many decades?

Is it useful? Hard for me to answer - I don't like rice, but most of my family does. They all swear by their Zojirushis and Tigers, so I have to imagine it provides a better cook than the old style.


> There's a lot of examples of that, like it still being called Unleaded Gas despite it having been so by default for how many decades?

Depending on where you live, about 0.35 decades?

> On 30 August 2021 the United Nations Environment Programme announced that leaded gasoline had been eliminated. The final stocks of the product were used up in Algeria, which had continued to produce leaded gasoline until July 2021.

- https://en.wikipedia.org/wiki/Tetraethyllead#Modern_findings


That's interesting, but obviously they meant 'in places where it has been banned a long time', there being countries where that's not the case doesn't stop it being an example of this, that terminology/marketing sticks around outliving a point it might've been making.

The EU (incl. UK at the time) banned it 2.4 decades ago.


> On 30 August 2021 the United Nations Environment Programme announced that leaded gasoline had been eliminated.

Basic availability of leaded is unrelated to how long unleaded has been the default.


Nah. They've had a long time to perfect rice cookers. The $40 Walmart one works fine. If it turns out you use it a lot and you really want the nicer one, then spend the money for it. But honestly the cheap one is fine.


Rice cookers are still a bit of a novelty in Western countries but in Asia they are ubiquitous. It's like microwaves: expensive in the 80s now they are mass produced and sold for 80 dollars.


I find the nicer ones tend to do a more consistent and better job. With the cheap ones the bottom is often drier than the top. Timers are great and so are modes for different types of rice.


I had a $15 Aldi one that worked fine. I'm sure the high end ones are better in some ways, but it's sorta like drip coffee pots, there is only so much you can improve upon.


Zojirushi offers a wide range of rice cookers. We just have the basic one and it works well, but they have higher end ones that cost 4x the price that we bought ours, I’m not sure if the rice is actually better in the higher ends Zojirushis. They even have cheaper ones that use fuzzy logic, it looks more like an economy thing over the traditional non stick pressure based rice cookers.



I guess to me that feels basic? Is it really something worth advertising?


It's typical for 50+ year old technology to be considered basic. Especially by those who may not remember the before times.


This same mechanism is how a dryer knows when the clothes are dry.


>This same mechanism is how a dryer knows when the clothes are dry.

I've never had a dryer where that feature actually worked. My newer samsung claims to have that, but the drying time still seems to just use the timer (even when using the sensor setting) and they clothes are almost never 100% dry when the timer runs out. I suspect maybe it'd work if the clothes got dry before the timer ran out, but the timer settings always seem to be just short of how long it'd take to dry a load.


Usually for me it struggles if I'm mixing types of cloth. If there's one pair of denim jeans it'll stop when everything else is dry, but the denim isn't.


Heat pump driers are known not dry clothes 100% too.


Do the InstantPot has this basic control circuit which even the cheapest rice cooker has. I ambnot finding clear information on this online.


From my experience operating it I reckon it does the following: after you fill it and start, it starts heating and measures the time it takes to reach 100°C. This allows it (in the rice program) to figure out the amount of mass present and adjust the simmering time under pressure accordingly.

Using the same trick (in alll programs) it figures out overfilling and aborts for safety reasons.

Edit: I think the only sensor needed is a temperature sensor.


If it had a temperature sensor it could just figure out when the temperature starts rising above the boiling point of water.


No it doesn't. Still prefer my instant pot though because it is so much faster and can make much larger volumes of rice


> 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).

hopefully the "large volume ice cube" is something like a saturated salt or sugar solution so that the ambient temperature it tries to hold is colder than the melting point of the popsicles.


There are also neuro-fuzzy control based devices [Slide #4]

https://users.ece.cmu.edu/~koopman/lectures/ece348/22_contro...


Can one make towel rack/drier using same way?


Thermostats also used to use the bimetal trick


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.


There other inaccuracies. To give just one example:

>One of the key differences between the Japanese and Chinese rice cooker is that the latter has a glass lid, which Chinese cooks demanded so they could see when to add sausage.

The average Chinese rice cooker looks exactly like the Japanese ones. Cookers with glass lids exist but are uncommon in China. In fact if anything, I've most often come across those glass lid ones in the West, not in East Asia. Also the sausage part is so random, lol.

The article is badly researched. A couple of years ago I'd have said I'm shocked a university professor wrote this, but frankly at this point it's to be expected.


IEEE spectrum has gone way downhill, there’s literally no fact checking beyond brief google searches at all for most articles nowadays.


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.


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?


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.


Isn't vinegar made from alcohol? So it's more like an assembly line of sugar to alcohol to vinegar?


Both. They can make acetic acid from both sugar and ethanol.


Acetate from glucose requires oxygen


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.


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.


>the oven with the pilot light on.

Those still exist, or do you just mean the interior light bulb?


Pilot light surely means it's a gas oven.


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.


It's pasteurisation, your 50C-only yoghurt would potentially not last as long; possibly even succumb to unwanted bacteria before (or the wanted be outcompeted by the unwanted) turning to yoghurt.

I don't measure it to 80C, just heat milk until it breaks then switch off and let it cool. I didn't have a thermometer when I first made it, but now I might measure that it had cooled enough. I wouldn't say it has to be as hot as 50C, you just probably don't want it hotter, so if you're making it without just let it cool to tepid, feeling warm to the touch, then add whatever you're using. Cheese similar, just more specific cultures.

(And I suppose if you really get into it, the specific temps and holding them thing is a lot more true for cheeses - or rather for different types - than it is for yoghurt.)


The gallon milk jug we get in the USA, does that need to be pasteurized too? I'd assume they're already pasteurized.


Fair point, I suppose if it's freshly opened and poured straight into a vessel out of a (not-eco) dishwasher cycle then it probably is a redundant step. Any relaxation from that doesn't mean it's definitely going to be an issue, just increasing the likelihood, or increasing the bacteria competition, it's not black and white.


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.


Also noteworthy but little-known is that unprocessed milk from a farm has up to 5% fat - you can't buy milk with that much fat in a supermarket.


If you happen to be in the UK - Graham's Dairy milk (sold in supermarkets) is 5%. But you're right that 'whole milk' is 3.5% or greater, typically 3.7% for supermarket own brand. Gold top or Jersey is 5%.


I'm in Germany. "Full fat" is 3,5%, sometimes premium milk has 3,8% and I think that's the highest I have seen. When I was little, we had milk from a farm in the village and I sometimes went to fetch it.


I just add heavy cream to the milk for yogurt, has the same effect and is delicious.


In Finland they sell some small portion-bowls with a thin solidified cream layer on top. It's not yoghurt but something we Swedes call "Långfil" [1]. It has a very funny consistency, it doesn't stick to the spoon as normal youghurt and is very delicious!

[1] https://sv.wikipedia.org/wiki/L%C3%A5ngfil


yes, and even in a no-tech scenario, as i said here:

https://news.ycombinator.com/item?id=42029736

:)


A vacuum flask keeps the temp pretty consistent for a long time though. I doubt anyone thinks it needs to be perfectly consistent, just within the range that the bacteria can survive.


If by consistent you mean within 20 K of the starting temperature.


Technology Connections covered rice cookers: https://youtu.be/RSTNhvDGbYI?si=PxZYi4YYs9nixATv


Technology Connections is generally awesome, but this particular video was even more fascinating than its usual.

Instead of a bimetallic switch like discussed earlier in this same HN thread, there's a lump of metal in contact with the pot, which stops being responsive to a magnet at a certain temperature (past its curie point) and that's what triggers the switch from "cook" to "keep warm" (and yes, of course it all works due to the huge latent heat of water).

So they came up with an alloy whose curie point is just above water's boiling point, and thanks to that, the circuit, nah, the whole thing is comically simple - just a shunt, a spring, a big resistor and the heating element (and ok a led or 2). The weight of the pot is also acting against the spring, ensuring you can't actually select "cook" if the pot isn't there. This is so brilliant.


That's an excellent video. Before watching it I didn't realize there were so much physics involved in making the rick cookers.


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.


Always with the latent heat. :)



8 names doesn't disprove "it isn't often".

"It isn't often" doesn't mean "it has never happened".

If anything, only listing 8 only proves their point. To disprove their point you'd need to list hundreds of housewives. Possibly thousands given the number of patents out there.


Entire books have been filled with home remedies, sewing ideas, and cooking methods. You could, perhaps, cite the editors of those books, but the "individual housewives" who contributed them would not have traceable identities.

The ideas and methods were shared among communities, church groups, in schools, and handed down in families. Often by oral tradition and by illiterate people.

In modern times, you could check the archives of Heloise, and magazines such as Good Housekeeping and Sunset. Columnists would usually receive hints and tips from readers, and give credit at that point.


>Entire books have been filled with home remedies, sewing ideas, and cooking methods. You could, perhaps, cite the editors of those books, but the "individual housewives" who contributed them would not have traceable identities.

Those sorts of things aren't usually traceable when men invent them either though, it's basically unrelated to the larger subject of women not getting credit for inventions in science.


Define often...

This feels like an argument only for the sake of hearing one's self out loud, a poor man's denying the antecedent fallacy.


Fumiko Minami(三並風美子)'s knowledge and contribution to the development of the rice cooker is greatly appreciated, but she is rarely mentioned in Japan. I think it deserves more attention.


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.


> He describes making perfectly fluffy and buttery rice

If your rice is buttery I think they're doing something wrong.


Yeah, buttery seems at odds with fluffy, unless you're describing a croissant.


The #1 Zojirushi product is the hot water dispenser. Doesn't matter if 120V heats slowly if you've always got it ready.


My parents had a traditional pressure cooker that was both intimidating (they convinced me it could blow up any moment) and useless for recipes when I asked them how to cook things. "Oh, just cook it for two whistles" Two what?

Instant Pot was sooo much easier. Safety interlock, unambiguous timer, much better.


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%...


What if you want rice with your dumplings or pulled pork...?


This reads like an ad.


Zojorushi cookers are definitely the Bentley of rice cookers


It's true though. Another great thing is that the IP will have regular white rice done much faster (~15 minutes for perfect rice).


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.


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.


You can get some very fancy rice cookers in Asia, with lots of buttons. Some of them really do produce a better end result.


I use a Zojirushi NS-LAC05. (I believe the current version of this model is the NS-LHC05.)

https://www.zojirushi.com/app/category/rice-cookers

It makes great rice consistently and easily.

The only quirk is that their "cup" measure is 1 gou (一合枡), which is just over 3/4 of a US cup. It's just a cultural thing, but the adaptation I had to make was real — I got this rice cooker as a hand-me-down from an Asian friend, and it didn't include the OEM 1-gou cup. It took a bit before I figured out how to get the proportions right.

The results are better than what my parents used to get with their old Black and Decker RC400. It's possible that there was user error involved with the RC400, which I recall burning on the bottom. I've never burnt any rice with the Zojirushi, and I'm not even sure how I could go about it if I wanted to. Certainly the Zojirushi produces better rice than I used to make cooking it on the stovetop in an ordinary pot.

I'd like to know just how the Zojirushi gets such great results. My guess is that it's some combination of good temperature measurement and even heat application to ensure that their well-researched cooking formulas get accurately applied.


Thanks for reminding me - I also used to own a Zojirushi, and all the conversions were a lot more headache than I've had with my Instant Pot. I had to write down all the calculations on a 3x5 card, and then try not to lose that, or get it wet in the kitchen!


I just take a 1-US-cup measuring cup and fill it 3/4 full for each "cup" that the Zojirushi wants. Like a "heaping cup" in reverse.


>I just take a 1-US-cup measuring cup and fill it 3/4 full for each "cup" that the Zojirushi wants.

I thought 3/4 was one of the 'normal' measuring cups in a set, but just googled it and I guess it's not.


The way I think about the Zoji cup is that one cup of dry rice makes one (US) cup when cooked. In other words, cooked rice is 33% more by volume than dry rice.


My mother's measure, from an old college cookbook: "One cup of rice make three cups of RICE". (With eyes springing wide open and fingers splaying outwards at "RICE", followed by a hearty giggle).

Our measures are way off from each other. Yours sounds like the "rice made for sumo wrestlers" I remember from an old story, where rice was made with progressively less water over time to toughen up the trainees.


I was surprised at the rice cooker section at Yodobashi Camera in Tokyo Akaba that they were serving samples of cooked rice from each of the many, many models they sell. My American senses failed to detect any difference. And yes, that was only one of the multitude of surprises in that wonderland of a store.


they really do, perfect rice everytime if you wash when necessary and use the proper rice to water ratios


Tastes and has the texture of Chinese restaurant rice. I use mine 3+ days a week. Worth it if you eat that much.


It's funny, because here in Singapore the gold standard for rice would be Japanese and Korean restaurants. The various Chinese cuisines aren't really all that renowned for their rice. (Just like eg the English technically have bread in their cuisine, but it's nothing to write home about.)


I can't say I know the difference, but I imagine the Japanese and Korean rices aren't like the 'boil in a bag' stuff Americans eat at home that I'm comparing it too.


Oh, approximately no one uses boil-in-the-bag rice in Singapore. Neither at home nor in a restaurant, even at the low end.

The various Chinese cuisines have serviceable rice, it's just that the premium stuff tends to be Japanese and Korean. (But it's not just a single 'quality' dimension. They differ in kind, too.)

Btw, you should try Nasi Lemak. It's a dish that has its rice in coconut milk. Very tasty.

https://en.wikipedia.org/wiki/Nasi_lemak


I only press one button ("Pressure") when cooking rice in my Instant Pot.

It remembers the last several settings I've used - one of those is 12:00 for rice.

If you don't have a pressure cooker, that's fine. But for those who DO already own a pressure cooker, I'm not sure how the lighter weight of the rice cooker is relevant. A single-use device takes up more room in the kitchen, and the accumulation of these devices just adds to our environmental disaster.


I do have both and still prefer the rice cooker for rice cooking. The lighter weight helps me move it around the kitchen as needed. I also like that it is easier to put in the dishwasher and that I never have to futz with the rubber seal or the hard to clean yet easy to lose pin and other small parts in the instant pot. It is always a chore for me to clean. The steps needed remind me of (not unhappy) times in the army having to assemble and disassemble an assault rifle.


If I making rice in the instant pot I can't use the instant pot to make actual food.

Also that 12 minutes is not inclusive of the 10 minutes it takes to get up to pressure, and the instant pot cannot keep rice warm throughout the day.


>Also that 12 minutes is not inclusive of the 10 minutes it takes to get up to pressure

This is a huge downside that people always neglect to mention with instant pots. Probably not a big deal with rice, since the other methods also take ~20 minutes total, but for larger meals, that extra time is a lot more than it takes for rice, and the slow release at the end is also somewhat necessary for other foods that don't completely cook during the short time that's recommended. Things like roast and such aren't 'done' just because everything is up to a reasonable temperature, that extra cooking that's done during the slow cooling of the release helps flavors develop.


How about soups? If a soup has multiple steps, you can easily end up paying the cost of building up temp and releasing twice.

Of course for bone broth, you are still savings many many hours, but the math isn't as simple as "bones 25 minutes, release, potatoes 5 minutes, release, carrots 3 minutes, release."


> If a soup has multiple steps, you can easily end up paying the cost of building up temp and releasing twice.

I think most people tend to avoid dishes that have multiple steps for that reasons. Generally the most you see is sauteing in the bottom of the pot before deglazing and adding more ingredients and bringing it up to pressure. Although I'm sure some people get fancier with them. At that point though, you probably aren't saving time or effort over just cooking normally.


So much arguing. Don't worry - I'm not going to confiscate or outlaw your rice cooker!

> If I making rice in the instant pot I can't use the instant pot to make actual food.

I'll just correct this one misinformation. You absolutely can cook multiple dishes at once - I've done it, google: 'pot in pot' - assuming they can tolerate roughly similar cooking times.


> I'll just correct this one misinformation. You absolutely can cook multiple dishes at once - I've done it, google: 'pot in pot' - assuming they can tolerate roughly similar cooking times.

I have the OG Instant Pot, it is too small for multiple dishes. Especially if I am making a bone broth soup + rice!

Honestly I am trying to think of a dish I've ever made in my instant pot that hasn't occupied a majority of the interior volume...


Our Zojirushi (NP-RC05, it's over 10 years old now) is actually advertised as pressure cooking the rice to make it taste better, so I guess the two devices are merging. And it has 8 buttons (you can select the rice type)


Also only needing to make single "cup"(rice measuring) is better for my use case. It takes longer, but I feel it is simpler process.


I cook one cup of rice in my Instant Pot all the time.


Hmm, if I use chicken broth instead of rice, isn't the end product just chicken soup instead of a rice dish? :D


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.


If between rice and water, you replace the rice with chicken broth, I'm pretty sure you don't get to cook much rice...


If all of it is absorbed, then it’s a risotto ( you just need onions and white wine as well…)


All absorbed? That's a pilaf, or a terrible risotto.


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.)


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.


Pot in a pot also minimizes cleanup, I'm a big fan but few people seem to use that method.


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.


You can solve this placing a trivet in the pot with your rice in a bowl on top. I do this when im in a hurry and need to rustle up ruce and lentils on the double. Lentils, stock, trivet, bowl, rice, water, done.


any downsides to using a rice cooker? never used one before, and I am thinking of buying one.


It takes up counter/kitchen space, and if you leave rice in it too long, it go bad and disgusting (so don't do that). It makes rice, and for me, I cook chicken and vegetables in it, just put it on top of the rice, for single pot meals. It comes down to how often you eat rice. It makes it way easier, since you set it and forget it (just don't forget too long).

Importantly though, they've had decades to refine the design, so the cheap one from Walmart does just fine, no need to buy a $100 Japanese one if you're exploring if you even want a rice cooker.


thanks.


To be clear, "too long" is more than 24 hours.

Feel free to make rice the night before if you have dinner plans the next day, it'll work out fine in a good quality Japanese rice cooker!


got it, thanks.


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.


>I like to prepare my rice as if were pasta (i.e., tons of water, which gets drained and discarded at the end)

It's funny how upset some people get by that method.


I love my InstantPot, but never use it for rice. The few times I've tried, I haven't liked the results. Boiled/steamed on the stove ftw. :)

Now soups, veggies, artichokes, enchiladas, ... For those things, the instant pot is awesome. =)


The simple rice cooker can cook rice till all water is absorbed. Can Instant Pot do that? I think the Instant Pot cooks till the timer runs out, not till when the water is all absorbed into the rice.


If you measure the right amount of water (not optional with either solution), 12 minutes should do the trick. And you can just let it sit on the keep warm setting for some time and it will continue to absorb whatever water is left in the pot.

I actually got an instant pot recently but I haven't tried the rice cooking setting yet for the simple reason that I use the instant pot for cooking sauces and other things that would go with the rice. Also cooking rice on the stove isn't actually that hard. I don't see how this saves me time or effort. Just measure out the quantities carefully and you should be fine.

Anyway, I need less carbs in my life; not more. One reason I got the Instant Pot is cooking lentils and beans becomes really easy with it. Also am making lots of tasty meat stews. Works great for that.


Nope, it's a pressure cooker, the cooking vessel is air-tight.

My favourite recipe is to use 1:1 rice to water ratio and the adjust the time depending on the rice. For example, white rice takes 5 minutes, basmati 6, brown 30(!). When it'đ finished, wait at least 10 minutes before opening the lid, let the pressure drop naturally.


I sometimes indulge in doing the KFC chicken rice cooker hack recipe. Look it up if you haven't yet.


I do a 1:1 ratio, but only let mine run for 3 minutes for white rice, 20 minutes for brown rice.


Yeah I use Instant Pot, sometimes replacing water with broth or if I am feeling fancy I'll add some saffron. Good to go.


A few people mentioning pressure cookers as an alternative. A heavy claypot is the ideal manual alternative for those with a gas stove.

Probably the most popular is “kamadosan”. It makes beautiful rice and you have control over it so eg it is easy to create a crust on the bottom if you like.

Unfortunately I have an induction stove now so a bit hard to use, but I occasionally cook rice on a small charcoal stove when enjoying the slow life.

Review: https://thejapanesefoodlab.com/kamado-san/ Recipes: https://toirokitchen.com/blogs/recipes


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...


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.


My ancestors ate a diet heavy in meat, butter and cheese starting about 7,000 years ago. They weren't the first to keep sheep and cattle for food, but they were the first farmers to do so. They're usually called the Germanic peoples, which by the way make up about half the ancestry of modern-day Italians, Spaniards and Scots -- and a larger fraction of the ancestry of the other Western European countries modulo Ireland.

So, I don't think the experience of people whose ancestors have been heavily reliant on rice for the last 4 or 5,000 years and until recently didn't have much access to meat is particularly informative for what I should eat.


  >claims regarding rice being unhealthy
The claim isn't that rice is unhealthy. The claim is that rice can potentially contain high levels of arsenic, which is easily avoidable by modifying the cooking method slightly.

As you say, measurable health effects from arsenic are confounded by the alternatives being largely "greasy and highly processed."

https://www.youtube.com/watch?v=EIM_zjCmQ5Y


Well having to soak the rice overnight and reboil it multiple times doesn't seem like an easy method to me.

Also saying rice is filled with arsenic and warn against eating it multiple times a day is not that different from saying it is unhealthy. It almost sounds like fear mongering to me considering how the Asians seem to be doing fine so far and it is the cultures that don't eat enough rice or carbs that struggle with being healthy.


  >Well having to soak the rice overnight and reboil it multiple times doesn't seem like an easy method to me.
Yeah, I'm not sure that's really necessary. Other sources say that simply boiling in lots of water (like pasta) and discarding the excess water is enough.

  >It almost sounds like fear mongering to me 
I don't mind, because that's an unrealistic and over-broad standard for speech.

I don't care what it "almost (!!) sounds like," especially after I took care to disabuse the reader of that exact misunderstanding. I care what it is.

Truth > Optics / PR

You can't stop telling the truth just because some people might possibly misinterpret your words (which, spoiler alert, people can always do that), or else you literally can't ever say anything.


Arsenic content is also highly variable depending on where the rice was grown.


Could be simultaneously unhealthy for Westerners and fine for East Asians.

Per the Lindy effect, we should all be eating foods that we're adapted to eating. You are likely adapted to a food if you and your ancestors have been eating it for thousands of years. The longer the better.

East Asians seem adapted to rice and its arsenic content. Northern Europeans, maybe not so much. The former has had thousands of years to adapt and select for rice-eating. The latter, again, not nearly as long. Another example: dairy. East Asians can't digest it, Northern Europeans can.


I don't normally bother to soak rice overnight. I believe you can get rid of most arsenic etc by changing the water once or twice during the boil. A final rinse in hot water before serving is good.

I mostly eat long brain brown rice which contains more contaminants in the bran and so this purification method is important to reduce one's intake of bad s*t.

Eating organic rice is good but doesn't mean it's uncontaminated.


Could you buy organic rice instead?


Organic rice still has arsenic. The arsenic is not coming from pesticides, but from the soil and water, which naturally carry some arsenic.


I found the ratio of rice and water to be the main issue - and the rice cooker didn't fix that. I stumbled upon a recipe with a different approach that I use now.

Take plenty of water and get it to a boil. Add any amount of rice to the boiling water, and let it boil for 8 minutes. Then drain the water, remove the pot from the stove and put the lid on for a few minutes. Reduces the need for measuring quantities.


I just use the included rice cup and fill to the correct line in the rice cooker pot...


I always use a ratio of water to rice (by weight) of 4 to 1 (e.g. 500 g of water for 125 g of rice).

I cook the rice in a microwave oven in a covered glass vessel (preventing the escape of water) and it is very good with this ratio.

For most other cereals that are either coarsely ground or whole grains, e.g. cornflour, semolina or wheat grains, the same 4 to 1 by weight ratio works fine when boiled in a closed vessel.

Most other kinds of starchy seeds absorb less water when boiled, so the ratio must be lower.

I assume that a dedicated rice cooker is useful only for those with numerous family members, who might want to cook large quantities of rice at the same time.

For smaller quantities, e.g. suitable for a couple of people, a microwave oven is very fast and reproducible, so there is no need for dedicated equipment.


What wattage is your microwave on?


It is controllable, but for rice and other cereals I use the maximum of 1000 W. Small powers are needed for things like meat or eggs, but very seldom for vegetables.

The time depends on the quantity. For around 125 g of rice + 500 g of water, the time is between 12 and 15 minutes.

An advantage of using a microwave oven is that no stirring is needed during cooking, unlike when boiling rice or other cereals on a traditional stove.


> Small powers are needed for things like meat or eggs, but very seldom for vegetables.

I understand why you would use low power for eggs, but meat? I always applied power in proportion to the product's water content, as it has high specific heat and absorbs microwaves readily. Meat is largely water so high power it is.


This may depend on the kind of meat. I cook mostly turkey, chicken or fish.

At high powers over 500 W my meat would explode.

Moreover, when cooking meat at a lower power for a longer time (e.g. up to between 20 and 30 minutes), the cooked meat is much more tender than when cooked faster.

If I boiled the meat, then maximum power could be used. However I do not boil it, but I roast it in the microwave oven in a covered glass vessel, with nothing added, except salt and condiments. Thus it is much more tasty than boiled.


Works great indeed. Another useful trick is to use a microwave. Simply put rice and the water in an open container in the microwave. Let it go at full blast for 14-15 minutes. Keep going until the water is gone. Let it sit for a few minutes and done. You get perfectly fluffy rice every time. Works great for small portions and it won't boil over.

I learned about this trick only a few years ago and when I tried it, I basically got a perfect result. Which was not what I was expecting.


How about the seasoning? Years ago I used to do this microwave rice but I threw in some powdered flavoring and it would boil & stick everywhere :/


The seasoning is better added and mixed immediately after taking the rice out from the oven, when it is hot and soft.

If you want to add some kind of oil, that is also better added immediately after taking the rice out of the oven.

If you add salt or sugar, then that should be added before cooking in the oven.


How do you prevent the rice from sticking to the bottom of the pot? Do you stirr it a few times?


Funny to see the discussions of instant pot vs rice cookers in the comments. We use one of each, often in conjunction with each other. Cheap and easy way to make a curry, for example. Never had any problems with the 3rd hand Zojirushi we have. Just follow the instructions and it gets the rice bang on each time.


> But how would an automatic rice cooker know when the 20 minutes was up?

How about a clock?

Now, I understand that in 1955 the required components might have been deemed too expensive, or actually the problem is more complex than that. This article is so poorly written. Like almost everything I've read in the last 20 years from IEEE Spectrum.


> How about a clock?

How would the rice cooker know when to start the clock? It needs to be started only after the water reaches a boil.


Well, I would have thought that once a temperature sensor reads 100 deg Celsius the clock would start. I'm sure there are good reasons why this wouldn't work well or is overly complex, but I would expect the article to discuss them.

From the article: > Fumiko found that heating the water and rice to a boil and then cooking for exactly 20 minutes produced consistently good results.

That knowledge about the ideal timespan of 20 min seems to be completely irrelevant to the implemented solution.


> That knowledge about the ideal timespan of 20 min seems to be completely irrelevant to the implemented solution.

Partially. They also mentioned that it was generally believed that you needed to vary the temperature during cooking to get fluffy rice. Fumiko's discovery is just as much about the fact that you can use a straight boil the whole time as it is about the duration.


I had the same question, and this article definitely could have discussed other potential engineering approaches and why they didn't work to provide the full context. To be honest, I learned very little from the article -- I already know how rice cookers work, so I want to learn much more when I decided to read the article


I just use 2:1 water to rice ratio, boil, reduce to low heat/simmer covered for 15 minutes, generally perfect.


This is an interesting mechanism, but is it really that difficult to boil rice for 20 minutes? I'm not exactly Gordon Ramsay, but I don't think I've ever failed to make decent rice.


It depends on how much rice you are making, how often you make it, and if you'd like it to be setup overnight and started on a schedule for you for certain types of rice and other grains.

Rice cookers can generally make a pretty large volume and they're still rather efficient at doing so. If you get the water and rice ratio to your liking it will make nearly perfect rice every time at the press of a button. The best ones have multiple markings for white and brown rice on the bowl so you don't even need a measuring cup to do this.

It has a little countdown timer so you can get your sides ready on time. It plays a little song when it's done. It covers and seals up well and can keep rice warm and good to eat for a few hours.

There are only two parts that you have to wash, the bowl itself and the detachable lid seal, and one you have to wipe down, the steam vent cap.

I generally don't like special purpose tools in my kitchen. The rice cooker has been a part of it for 20 years anyways. It's simply too useful without any additional hassle that it has easily earned it's place.


In many Asian households, rice is a part of breakfast, lunch and dinner. Boiling rice and washing the pot for every meal is a lot of work. Instead with a rice cooker, you set it the evening before with a timer. Rice is automatically ready in the morning for breakfast, you take out the breakfast portion and close the cooker again. It now goes into warm mode and keeps the remaining rice fresh and warm for the remaining meals of the day where you can just take out a portion here or there.

If you're eating a more western diet with rice only a handful of times a week, it's probably overkill as a single-tasker.


It's very difficult when you only have a wood or charcoal stove that needs to be fanned for 20 minutes at a constant rate or else the rice will burn. Which is why the electric rice cooker was such an amazing creation. It's in the article about the inventor of it.

As for today? Well, too hot on the stove or a phone call comes in, and poof, there goes all the water and the rice burns. If you're making rice 3 times a day, it's easier and safer to cook in a machine that guarantees perfection every time.


You don't simmer for twenty minutes. You simmer for ten and remove it from the heat for the remaining ten. The rice never burns because it is still quite wet when you remove it from the heat. Start with twice as much water as rice (by volume) and it comes out perfectly. I've been cooking rice like this for thirty years and it's always great.


That's synchronous cooking. Think of a rice cooker as asynchronous cooking. You turn it on, walk away, come back whenever you're ready and you've got rice waiting for you. It is extremely convenient.


The best analogy is a toaster

Is it really that hard to grill bread? Nope, but you have to pay attention somewhat to stop it burning.

Once you hit a certain volume of usage, an automatic device makes a lot of sense.


Toast needs more attention than rice


>Toast needs more attention than rice

Not really, you can make toast on the stove in about 1 minute, rice takes 20.


That cooking time not attention time.

For rice nearly zero attention is necessary with the correct amount of water.

And in that 20 minutes you get enough rice to fill mutiple people up.


Think of it as asynchronous cooking. You turn it on, walk away, come back whenever you're ready and you've got rice waiting for you.


Considering the proliferation and popularity of the rice cooker, the answer is a resounding and obvious "yes"


The article is very thin on details. For example, why not use a mechanical timer like many other appliances did and still do? That's the kind of detail an IEEE reader might appreciate.


A timer doesn't work because it takes longer to boil three cups of water compared to one. The bimetallic mechanism is agnostic of the amount of rice being cooked.


In the design being described there is an outer water reservoir where the water is being boiled away specifically as a timer. An alternative would be to have a bimetallic strip detect when the rice pot comes to temperature, lower the temp, and start a mechanical timer that could be set by the user. The advantage would be a significant energy savings vs. boiling water away as a kind of crude timer.


The 20 minutes is for ideal conditions. The article explained the goal was to boil away the water and then reduce the heat. The time needed may change with different ambient temperature or humidity.


I have a Philips fully automatic coffee machine that goes feom beans and water to espresso. Is there such a thing for rice? (Yes im that lazy/disorganized)


I love my rice cooker but people should defo be soaking there rice overnight or something.. (before use)

BBC News - https://www.bbc.co.uk/news/health-38910848 Should I worry about arsenic in my rice? - BBC News


The research about arsenic in rice is all over the place. Some claim that rice in India and Pakistan has the lowest level of arsenic. I would question that claim as India/Bangladesh has a problem with arsenic in groundwater causing skin lesions. Meanwhile in the USA, we used to put arsenic in chicken feed.

I would prepare rice the way it is commonly prepared through out the world. Eat white rice as the bran contains some of the arsenic. Wash the rice thoroughly before cooking.

https://pmc.ncbi.nlm.nih.gov/articles/PMC1241574/ https://pmc.ncbi.nlm.nih.gov/articles/PMC4772235/ https://pmc.ncbi.nlm.nih.gov/articles/PMC9603767/ https://www.pbssocal.org/food-discovery/food/fda-finally-ban...


Imagine a rice cooker (perhaps with pressure) that gives you data and control.

Modulate the applied power (pwm), read a few thermocouples, pressure sensor, release solenoid. Make it all programmable, let people program it.

I speculate that the usual strategy would be full power to get things warm while extracting an estimate of the specific heat of the contents. oh, maybe add a scale, so you can estimate the water content. I guess that once you get things hot, the specific heat of a rice-water mixture changes, so you want to ramp down the power. Validate that by looking for an increase in pressure. Heck, maybe different kinds of rice (or different rice dishes) would benefit from different heat-pressure schedules.

Think of it as a Decent (espresso) machine, but for rice. And open-source, please.


I've had no luck with that devices, moreover the instructions advised against broth, just water. But found out that with the right proportion of liquid and rice, a regular pot, six minutes on the vitro and ten minutes after switching out the power, gives perfect paella. So simple that I wonder how people spends money on widgets or are watching the whole process to add water.


I learned how to cook rice properly in India, just pot, water, some salt in right quantities and timing. Did that for decade at least.

I still use rice cooker though these days, even more trivial to operate, can't mess up things if I miss the final part, and it will keep it warm for hours. Extremely practical. Its also baby trivial, at least the device we have (which is not pure rice cooker rather some multi stuff with rice as one of many options, but we basically just do rice and yogurt).

Also, paella may be a fine food (if eaten in Spain or affiliated countries), but that type of rice has nothing to do with usual type of rice used as side dish. I actually don't know how to cook that type of rice well.


The same method works for any type of "dry" rice cooking. With "dry" I mean that all the liquid ends in the rice, no soup. The main advantage over cookers is that you can use chicken or seafood broth and add any other ingredient before the rice. You can still use it for white rice, just rice and salt.

My favourite recipe is to sauté chopped onions and peppers, a little garlic and black pepper, add shrimp, cuttlefish and clams, and then top up the water to the required amount and add the rice when it boils. Six minutes with the vitro on and, in ten more, it is delicious.

Change the seafood for mushrooms, chicken or whatever you like.


I learned how to cook rice properly from my Mom. Pot, 2x water, boil then turn to low, add rice, 18 minutes, done. My only gripe is that I'm still trying to find a good rice pot with the little steam vent in the lid.

The rice cookers I've seen take twice as long to make rice that is by no means twice as good.

To each, their own. My Mom loves the rice cooker I gave back to her because it took too long to cook rice. =)


I too love my rice cooker, but peeps should defo be soaking rice overnight before using or something:

BBC News - https://www.bbc.co.uk/news/health-38910848 Should I worry about arsenic in my rice? - BBC News




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