5 ms·

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

by 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.
    - StavrosK 10y ago
      Lucky for you, I already jammed my cheapo multimeter into the leads of an outlet, and I'm fine. The multimeter did explode, and it turned out that I was measuring voltage- and had the lead going to the amp section of the meter, so it kept showing 0 after its fuse blew. I figured the socket was dead, good thing I didn't stick my fingers in there.
      - TorKlingberg 10y ago
        I'm not sure you can connect a Fluke's amp meter to an outlet either without blowing it. Hopefully, just a fuse.
        StavrosK 10y ago

by 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.
  - StavrosK 10y ago
    Lucky for you, I already jammed my cheapo multimeter into the leads of an outlet, and I'm fine. The multimeter did explode, and it turned out that I was measuring voltage- and had the lead going to the amp section of the meter, so it kept showing 0 after its fuse blew. I figured the socket was dead, good thing I didn't stick my fingers in there.
    - TorKlingberg 10y ago
      I'm not sure you can connect a Fluke's amp meter to an outlet either without blowing it. Hopefully, just a fuse.
      - StavrosK 10y ago