Poor man's sous vide

[atomicsmoke]

I had a cold smoked ham that i wanted boiled. We like it that way. I thought i'd try sous vide once. I don't have a circulator so i came up with an improv: use the slow cooker on "keep warm" setting and turn off periodically when the temp goes over a threshold. I thought i was so smart then i looked it up - it's been done - a lot. LOL

The perfect rig would use a temp controlled power plug so the the feedback loop turns the power on and off. That doesn't work with my cooker since it's a dogital model.

So i just shut it off and on between 140F and 147F. The cycle was over an hour long so it wasn't labour intensive. At the turn off point the temp continued to for 3-4F before dropping.

The handle on the cooker lid broke a long time ago , which offered me an access hole for the temp probe (probe was measuring the water).

After 6h i pulled it out...IT 145.

It came out very nice: tasty, moist, tender.

No i am looking for a 2nd hand analog slow cooker.

 

[mike243]

Buy a hot plate that heats by induction ,havent cked how close mine is but it will boil water at 210,like any thing else the more you cAn spend the more accurate it will be,

 

[dr k]

My problem is I can't SV and run my smoker with the PID at the same time.

 

[hillbillyrkstr]

Lol atomic! Just because it’s been done before doesn’t mean your not smart! Lol!

Looks like it was a success! Ham looks great!

Scott

 

[johnmeyer]

I have a plain-Jane, manual on/off slow cooker. I built my own controller using an old microwave oven probe and some electronics I dreamed up. I stir the water occasionally during the initial warm up, to make sure the food gets up to temp quickly. After that, circulation isn't really necessary.

There are several other threads in this forum about DIY sous vide lash ups using a slow cooker. Here is one:

Mr. T's Multi Use - Sous Vide Cooker

The controller the guy uses is the one I would use if I hadn't built my own. It is cheap, accurate, and safe.

 

[atomicsmoke]

I have a plain-Jane, manual on/off slow cooker. I built my own controller using an old microwave oven probe and some electronics I dreamed up. I stir the water occasionally during the initial warm up, to make sure the food gets up to temp quickly. After that, circulation isn't really necessary.

There are several other threads in this forum about DIY sous vide lash ups using a slow cooker. Here is one:

Mr. T's Multi Use - Sous Vide Cooker

The controller the guy uses is the one I would use if I hadn't built my own. It is cheap, accurate, and safe.

Thats the controller i was eyeing.

 

[atomicsmoke]

I have a plain-Jane, manual on/off slow cooker. I built my own controller using an old microwave oven probe and some electronics I dreamed up. I stir the water occasionally during the initial warm up, to make sure the food gets up to temp quickly. After that, circulation isn't really necessary.

There are several other threads in this forum about DIY sous vide lash ups using a slow cooker. Here is one:

Mr. T's Multi Use - Sous Vide Cooker

The controller the guy uses is the one I would use if I hadn't built my own. It is cheap, accurate, and safe.

Johnmeyer,

Do you know if the willhi controller uses a relay or solid state device to control the power output? If relay any idea for how many actuations is rated for? It does not come with FCC markings does it?

 

[johnmeyer]

I had the same question, and searched for an answer just two weeks ago. I found a review by a fellow engineer (October 6, 2018) on the Amazon page for that product which said they still use a mechanical relay. I commented on this review, saying "The only question I have is how long that relay will last."

I have done a little research, and it appears that a typical mechanical relay used in this application will probably last at least a million cycles. If it goes on/off once a minute, and your typical cook is three hours, that would be 180 cycles every time you cook. If it lasts a million cycles, you'll have to use it over 5,000 times before you have to worry. If you use your sous vide twice a week, that means you use it 100 times per year. It will take you fifty years to wear it out.

A mechanical relay has the advantage that it will operate anything, including devices that might not be "happy" with the power drop across a solid state relay.

[edit]I changed "solid state" to "mechanical" in the last paragraph above.

 

[atomicsmoke]

A solid state relay has the advantage that it will operate anything, including devices that might not be "happy" with the power drop across a solid state relay.

I think you meant "a mechanical relay has the ....". I agree, but my devices are simple resistive elements that don't care about the voltage drop.

The mechanical life span might be in the millions of cycles, but when you put current thru its contacts the span drops. A large slow cooker runs at around 3A, a low powered smoker at at least 7A. We are probably looking at lifespans of few hundres of thousands of cycles. Still worth it for 30$. What do you think about the safety aspect? I dont think this is certified by some alphabet agency. Would you leave it running while away?

 

[johnmeyer]

Thanks for catching my error. I corrected that, and left a note in my post about how it originally read.

You are correct that the more current going through a switch, the quicker it will wear out. However, relays have been used in billions of applications over the years, many of them with the darn things clattering on and off all day long. I once visited an old "stepper" telephone central office, where all the phone calls were switched with "step-by-step" mechanical relays. You needed hearing protection because of all the noise. This was how phone calls were switched in the early automated phone network (i.e., when we quit using operators to make phone calls). The phone company had a 40 year MTBF spec for their equipment back then.

I did have the big interlock switch on my microwave oven begin to malfunction from the contacts getting burned, after 25 years of being used 10+ times a day. I was able to disassemble the switch, file the contacts, and get it working again (it was actually shorting out and blowing the circuit breaker).

So, generally speaking, relays and switches last a long time, but will eventually wear out from the arcing. However, I really wouldn't worry about it for this application, unless you are switching a motor. It is the inductive devices that are the hardest on relays. A purely resistive load like a slow cooker is a piece of cake (a microwave oven is highly inductive, which is why my interlock switch eventually failed).

As for safety, that has little or nothing to do with using a traditional mechanical relay, and more to do with how the probe is isolated. I have no information on that. Also, I cannot find anything about the manufacturer (it is a Chinese company) and therefore cannot find out if it has UL approval. Probably not.

As for leaving it running unattended, I don't see any problem with that. If you are concerned about failure, it can fail by keeping something on too long or by shutting down. Either one could ruin your food, but so could the failure of a toaster oven, slow cooker, etc. I just don't see anything with this device that is more likely to fail than any other piece of electrical equipment (most of which last almost forever).

For the price, I'd just get it and use it.

 

[atomicsmoke]

Thanks for catching my error. I corrected that, and left a note in my post about how it originally read.

You are correct that the more current going through a switch, the quicker it will wear out. However, relays have been used in billions of applications over the years, many of them with the darn things clattering on and off all day long. I once visited an old "stepper" telephone central office, where all the phone calls were switched with "step-by-step" mechanical relays. You needed hearing protection because of all the noise. This was how phone calls were switched in the early automated phone network (i.e., when we quit using operators to make phone calls). The phone company had a 40 year MTBF spec for their equipment back then.

I did have the big interlock switch on my microwave oven begin to malfunction from the contacts getting burned, after 25 years of being used 10+ times a day. I was able to disassemble the switch, file the contacts, and get it working again (it was actually shorting out and blowing the circuit breaker).

As for safety, that has little or nothing to do with using a traditional mechanical relay, and more to do with how the probe is isolated. I have no information on that. Also, I cannot find anything about the manufacturer (it is a Chinese company) and therefore cannot find out if it has UL approval. Probably not.

As for leaving it running unattended, I don't see any problem with that. If you are concerned about failure, it can fail by keeping something on too long or but shutting down. Either one could ruin your food, but so could the failure of a toaster oven, slow cooker, etc.

For the price, I'd just get it and use it.

The safety concern did not come from the mech vs solid state comparison, or from a food safety aspect; but from the fact that is an import. Some stuff on amazon does not seem to require UL/CSA certification. It's a device that carries a current high enough to cause an arc. If not properly designed does carry a fire risk. I do plan to purchase it , but i wouldn't trust it to run while I am away like i do with a slow cooker.

 

[zwiller]

I am all for rigging things up and enjoy DIY but with the popularity if SV there are tons of low cost options now. All UL rated...

 

[dr k]

For those that have an Auber plug and play and Bradley Smoker PID, Auber sent me this chart. They said for my Auber WS-1510ELPM to divide the P column by ten to get the correct value for my PID. So my out of the box setting was P=7, I=600 and D=150 which is the same as the bottom line in the chart for the Bradley Auber PID. So the slow cooker low overshoot (actually no overshoot) setting for mine is P=4, I=0 and D=40 based on the chart and is fantastic with no circulation needed from pic in post #3. The Mes Smoker works awesome in P mode, P=1, I=0 and D=0. These settings are way better than the auto tune.

 

[browneyesvictim]

I built the controller for my SV setup. It is not a PID per se but works well with an analog crock pot or rice cooker. And the best part it all cost less than $40 bucks. I followed an instructable I found online several years ago with some modifications.
https://www.instructables.com/id/Sous-vide-cooker-for-less-than-40/

For the controller I am using an Inkbird ITC-2000 ($16 bucks on Amazon)

For the temp sensor, I opted for a better quality waterproof sensor that the one that comes with the Inkbird. (Uxcell NTC 10K Ohm Waterproof Digital Thermal Temperature Sensor Probe 1m)

The outlet box I am using is a little larger than the one in the intstructable that houses a duplex recepticle- one switched, the other "always hot". Project box- (Hammond 1591USBK Black ABS Plastic Project Box -- Inches (4.7" x 4.7" x 2.2") mm (120mm x 120mm x 55mm)).

I just use a small aquarium bubble stone to circulate the water which the aquarium pump is plugged in to the "always hot" side of the outlet

The built in Inkbird relay is good for 10Amps which can easily power a rice cooker or small crock pot. However, I will shamelessly admit I have also used it with my 22 quart Nesco Roaster Oven and I didn't let the smoke out. :rolleyes: But adding a secondary relay is an option as well.

And your ham looks delicious!!! I think I just might have to bath my next one! LIKE!

 

[johnmeyer]

PID is probably not needed for this application. I say this even though sous vide does require very exact temperature control. The reason I think PID is, once again, overkill is that the thermal mass of a big water bath in a slow cooker (or other sous vide DIY setup) is gigantic compared to the 500-900 watt heater typically found in these devices. As a result, once the water reaches a set temperature and the thermostat turns off the heat, there is practically no overshoot. I have verified this myself with my own slow cooker. If you don't have significant overshoot (2-5 degrees or more), the anticipatory electronics in the PID is wasted.

However, if your controller is PID, that obviously is a good thing. All I am saying is that I wouldn't pay a dime extra for that feature in this application.

 

[daveomak]

used it with my 22 quart Nesco Roaster Oven and I didn't let the smoke out

Don't you just hate it when the smoke comes out of those electrical parts... Too bad they didn't put more smoke in them when they built them.....

 

[browneyesvictim]

Don't you just hate it when the smoke comes out of those electrical parts... Too bad they didn't put more smoke in them when they built them.....

And who ever said you cant get smoke with sous vide? Not exactly TBS though...

 

[atomicsmoke]

PID is probably not needed for this application. I say this even though sous vide does require very exact temperature control. The reason I think PID is, once again, overkill is that the thermal mass of a big water bath in a slow cooker (or other sous vide DIY setup) is gigantic compared to the 500-900 watt heater typically found in these devices. As a result, once the water reaches a set temperature and the thermostat turns off the heat, there is practically no overshoot. I have verified this myself with my own slow cooker. If you don't have significant overshoot (2-5 degrees or more), the anticipatory electronics in the PID is wasted.

However, if your controller is PID, that obviously is a good thing. All I am saying is that I wouldn't pay a dime extra for that feature in this application.

I get about 3 deg overshoot on mine on "keep warm". I am fine with that

 

[browneyesvictim]

Perhaps I am stating the obvious, but a PID and an electronic controller is not the same thing, and which are also different than letting the built-in thermostat of the device determine the mechanical hysteresis or dead-band. If the "keep warm" mode maintains temps accurately enough for your application then no need for either a PID or a digital controller.

 

[atomicsmoke]

Since then i bought an anova. So my Easter ham cooking got a little easier.

8h at 145...kept a perfect shape...1 cup of liquid in the bag (saved for a stew).