4 ms·

I've always wondered, why don't regular $30-50 rice/slow cookers have better temp controls.. cost would be minimal

by dharma1 10y ago

bravo22 10y ago
The cost is not in reading the temp. Cookers, and cooking systems in general have a lot of thermal inertia. You need a lot of wattage and a well designed PID to get precise temp control.
- 2muchcoffeeman 10y ago
  A now defunct company in Australia "Sous Vide at Home" actually sold a PID controller that converted a basic rice cooker - it won't work with a fancy one - into a rough temp controlled water bath. I have one. It actually works pretty well for a lot of things. The temp swing is a bit poor compared to other machines, about 2 degrees. But for the $120 I paid for it, it's pretty great.
  - tptacek 10y ago
    Auber Instruments has been selling these for about 10 years now. I can only assume the prices have come down steeply; I bought mine (including the thermocouples) for around that much in 2007 (I think?), but that's now the price point for a circulator that's about as capable as the PolyScience Pro that I replaced the Auber with.
  - joezydeco 10y ago
    Dorkfood is still selling their DSV for $99 on Amazon. I've been using one for years with a cheap crock-pot and it works really well. Their PID control is excellent. https://www.amazon.com/Dorkfood-Sous-Vide-Temperature-Controller-DSV/dp/B0088OTON4 https://www.amazon.com/Dorkfood-Sous-Vide-Temperature-Contro...
- gh02t 10y ago
  Eh not really, it's just a resistive heating element + impeller + temperature sensor + microcontroller. And implementing PID and tuning the parameters is not that hard as it's such a common and well-known algorithm. I built a sous vide cooker myself with a 500W heating element and tuned it well enough to hold +/- .05 degree in a matter of a couple afternoons for like $20 in parts. The difference with a commercial product is first and foremost safety. You've got high current electricity and moving parts in a high temperature environment, all underwater. The difference between what I made and something like the Anova is that the Anova isn't going to kill someone and also it will work reliably without the user needing to fix and tweak stuff (and that by itself is a feat, considering the environment an immersion cooker is designed to operate in). If I sold what I made as a product it would break and kill someone. All that kind of engineering and also the important work of optimizing user experience is not something manufacturers of most rice cookers care about. It's not worth the extra engineering effort. That said, there are some pretty fancy high-end rice cookers that have pretty precise control and maybe these sort of features may creep in on those, but that sort of rice cooker is a whole different beast than the little Panasonic cooker that lives on my counter.
  - tptacek 10y ago
    At the time when PolyScience released the "Creative series" circulators for something like half the list price of the Pro, apparently the only major difference between the two devices were that the Pro was rated for constant use in food service businesses, and the CS was rated for home use. Both could circulate a bathtub.
    - gh02t 10y ago
      Yeah, you have to pay for the extra liability the company incurs by rating things for extreme usage. I draw an analogy with multimeters. I've got a cheapo multimeter with a safety rating that (dubiously) claims it's perfectly fine to jam the leads in an outlet. Would I? Hell no, it'd probably explode. Meanwhile I have a much more trustworth Fluke meter that cost literally 100x more that doesn't really do anything more than the cheapo but I'm not putting my life at risk probing an outlet. You pay for that confidence, not only because there is a much larger engineering effort required to design and test a safe device, but also because you expect that they would be held accountable if their shit gets you killed. A legit safety rating is incurring a substantial liability.
deleted 10y ago
[deleted]
kelvie 10y ago
Instant Pot is basically this, isn't it? I've always dreamed of one day starting a company that made what was essentially the Instant Pot, and they did it first (and coincidentally also from my home town).
mattmaroon 10y ago
I looked into building such a unit. The problem problem with that style machine (like the sous vide supreme) is the heating element. It's a flexible mat. Getting it at a sufficiently high watt density, to keep it from taking forever to preheat and totally sucking wind when you add a big hunk of cold meat, is expensive. In that industry your build cost generally needs to be about 25% of retail, so an extra $20 for your heating mat means $80 more at the store. It's also less accurate temperature control because the thermocouple isn't submersed. It's a strip on the outside of a metal pan. Rice cookers and crock pots don't have to heat up nearly as much water (which has a high specific heat capacity) as a sous vide machine big enough to handle a slab of ribs.
- peterclary 10y ago
  That's interesting, so it's like sitting a pan on a radiant heating element on the hob? Induction hobs are more efficient and responsive than radiant heat hobs, so I wonder if induction heating the metal pan would be the answer here too.
- jwildeboer 10y ago
  The Kenwood cooking chef is IMHO the (expensive) example on how to get this right. Inductive heating, very precise and even heat distribution. And goes up to 140°C. Thermomix stops at 120°C. But for me it is too pricey. I am thinking of hacking the Kenwood kcook and add better temerature control to it, though :-) With an ESP8266 - boom. DIY connected kitchen device!
  - tptacek 10y ago
    I don't understand these devices. If I already have a circulator (and an oven and a range), why would I want one of these?

I've always wondered, why don't regular $30-50 rice/slow cookers have better temp controls.. cost would be minimal

by dharma1 10y ago

I've always wondered, why don't regular $30-50 rice/slow cookers have better temp controls.. cost would be minimal

The cost is not in reading the temp. Cookers, and cooking systems in general have a lot of thermal inertia. You need a lot of wattage and a well designed PID to get precise temp control.

2muchcoffeeman 10y ago
A now defunct company in Australia "Sous Vide at Home" actually sold a PID controller that converted a basic rice cooker - it won't work with a fancy one - into a rough temp controlled water bath. I have one. It actually works pretty well for a lot of things. The temp swing is a bit poor compared to other machines, about 2 degrees. But for the $120 I paid for it, it's pretty great.
- tptacek 10y ago
  Auber Instruments has been selling these for about 10 years now. I can only assume the prices have come down steeply; I bought mine (including the thermocouples) for around that much in 2007 (I think?), but that's now the price point for a circulator that's about as capable as the PolyScience Pro that I replaced the Auber with.
- joezydeco 10y ago
  Dorkfood is still selling their DSV for $99 on Amazon. I've been using one for years with a cheap crock-pot and it works really well. Their PID control is excellent. https://www.amazon.com/Dorkfood-Sous-Vide-Temperature-Controller-DSV/dp/B0088OTON4 https://www.amazon.com/Dorkfood-Sous-Vide-Temperature-Contro...
gh02t 10y ago
Eh not really, it's just a resistive heating element + impeller + temperature sensor + microcontroller. And implementing PID and tuning the parameters is not that hard as it's such a common and well-known algorithm. I built a sous vide cooker myself with a 500W heating element and tuned it well enough to hold +/- .05 degree in a matter of a couple afternoons for like $20 in parts. The difference with a commercial product is first and foremost safety. You've got high current electricity and moving parts in a high temperature environment, all underwater. The difference between what I made and something like the Anova is that the Anova isn't going to kill someone and also it will work reliably without the user needing to fix and tweak stuff (and that by itself is a feat, considering the environment an immersion cooker is designed to operate in). If I sold what I made as a product it would break and kill someone. All that kind of engineering and also the important work of optimizing user experience is not something manufacturers of most rice cookers care about. It's not worth the extra engineering effort. That said, there are some pretty fancy high-end rice cookers that have pretty precise control and maybe these sort of features may creep in on those, but that sort of rice cooker is a whole different beast than the little Panasonic cooker that lives on my counter.
- tptacek 10y ago
  At the time when PolyScience released the "Creative series" circulators for something like half the list price of the Pro, apparently the only major difference between the two devices were that the Pro was rated for constant use in food service businesses, and the CS was rated for home use. Both could circulate a bathtub.
  - gh02t 10y ago
    Yeah, you have to pay for the extra liability the company incurs by rating things for extreme usage. I draw an analogy with multimeters. I've got a cheapo multimeter with a safety rating that (dubiously) claims it's perfectly fine to jam the leads in an outlet. Would I? Hell no, it'd probably explode. Meanwhile I have a much more trustworth Fluke meter that cost literally 100x more that doesn't really do anything more than the cheapo but I'm not putting my life at risk probing an outlet. You pay for that confidence, not only because there is a much larger engineering effort required to design and test a safe device, but also because you expect that they would be held accountable if their shit gets you killed. A legit safety rating is incurring a substantial liability.

deleted 10y ago

[deleted]

kelvie 10y ago

Instant Pot is basically this, isn't it? I've always dreamed of one day starting a company that made what was essentially the Instant Pot, and they did it first (and coincidentally also from my home town).

mattmaroon 10y ago

I looked into building such a unit. The problem problem with that style machine (like the sous vide supreme) is the heating element. It's a flexible mat. Getting it at a sufficiently high watt density, to keep it from taking forever to preheat and totally sucking wind when you add a big hunk of cold meat, is expensive. In that industry your build cost generally needs to be about 25% of retail, so an extra $20 for your heating mat means $80 more at the store. It's also less accurate temperature control because the thermocouple isn't submersed. It's a strip on the outside of a metal pan. Rice cookers and crock pots don't have to heat up nearly as much water (which has a high specific heat capacity) as a sous vide machine big enough to handle a slab of ribs.

peterclary 10y ago
That's interesting, so it's like sitting a pan on a radiant heating element on the hob? Induction hobs are more efficient and responsive than radiant heat hobs, so I wonder if induction heating the metal pan would be the answer here too.
jwildeboer 10y ago
The Kenwood cooking chef is IMHO the (expensive) example on how to get this right. Inductive heating, very precise and even heat distribution. And goes up to 140°C. Thermomix stops at 120°C. But for me it is too pricey. I am thinking of hacking the Kenwood kcook and add better temerature control to it, though :-) With an ESP8266 - boom. DIY connected kitchen device!
- tptacek 10y ago
  I don't understand these devices. If I already have a circulator (and an oven and a range), why would I want one of these?