I recently fabricated a cheese bath cooker. Here are some pictures.
The tub and lid I bought at Cash & Carry.
The SS warming tray and lid I got used at a restaurant supply store.
I had, left over from a home brewing project, a 1500 w 120 vac heating element.
Not pictured is a 5 gpm immersible aquarium pump to help with avoiding stratification in the bath.
The tub lid was cut out so that the lip of warming tray rests on it.
What I learned from my first use of the system is that I need a second thermometer in the water bath to complement the one that is in the milk. At one point I overshot a target temperature because the milk temperature continued to rise due to the bath being to hot.
My only real gripe is that pouring off the whey is difficult because the warming tray does not have handles. I plan on mounting drawer pulls to save my finger nails and tips.
micah, great work/construction!
Good idea on the drawer pools to lift up the warming tray, another way would be to cut a notch on each end in the tub lid so that you can save your finger nails.
Also, to make it lighter, member DeejayDebi in her warming tray uses a plastic mat to move the curds away from the end wall and then a syphon tube to remove most of the whey. You can see it in a couple of her pictures.
Great setup. I ran into the same situation with my cooker. i have learned that if I want my milk at a certain temp, I need the water to be 1-2 degrees higher. So when I am raising milk to 102 degrees I stop the heater when the water reaches 104. I have not had a problem with the water not self-circulating since the heater is on the bottom and the hot water rises up the sides but I could see that advantage in having a pump. I found a immersible thermostat to regulate the water temp automatically for me but I have not bought it yet. Good luck with your cooker. By the way how much does it hold?
I like the siphon idea. No idea why I didn't think of it as I have tons of different diameter food grade tubing I use for beer/wine. Siphoning most of the whey out will make the drawer pulls unnecessary I suspect.
The warming tray is 12" x 20" x 6.5" (W x L x D).
In my first run I comfortably cooked 4 gallons. 5 gallons would be doable.
Here's a picture with the 4 gallons in it.
Very nice vat Micah! I am impressed you did a great job there.
great looking vat set up Micha, until you get the draw handles attached you could try sliding a thin metal spatula or knife (not sharp) under the insert to lift it high enough to get your fingers under it. Used to have to do it this way when working in kitchens. Handles would be easier on the hands though.
Helen
Thanks everybody for all the feedback and encouragement. I enjoy building things like this (perhaps as much as I like using them). I still need to encapsulate the electrical contact end of the heating element as there is the possibility of slopping water or whey on it.
I also have a microprocessor based circuit board I built for controlling the temperature of fermenting beer that I could easily use for turning the heating element on and off. I'll have to rewrite the firmware a little so it displays two temperatures (bath & cheese) simultaneously. Oh, and program in stepped temperature risings (e.g., 86F to 101F over 30 minutes, etc.). I'll let you all know how it goes.
I am very interested in the thermostat you are designing. My heating element is 2500w 240v because the 1500w 120v element did not heat the water and milk fast enough. (24 gallons of milk and about 12 gal of water.) If you can duplicate it and it works I would love to contract you to make one. I just use my breaker and thermometer right now.
I used a pvc "90" joint and a short piece of 1.5 inch pipe to encapsulate my element end. I am attaching a pic and you can see the pipe on the right side. Since taking this pic I have changed it out with a piece of insulating foam and electrical tape. Just throwing out ideas for you. Sounds like you are a pretty good problem solver yourself. :)
Quote from: FarmerJd on November 02, 2009, 07:15:07 PM
I am very interested in the thermostat you are designing. My heating element is 2500w 240v because the 1500w 120v element did not heat the water and milk fast enough. (24 gallons of milk and about 12 gal of water.) If you can duplicate it and it works I would love to contract you to make one. I just use my breaker and thermometer right now.
The "thermostat" I built is totally overkill. It is a custom built circuit board with an AMD microprocessor, analog to digital converters (for thermistors), relay switches to turn things (like heating elements or freezers) on and off, and a serial connection to interface with a computer for displaying status and programming the firmware. It was a good exercise but I doubt I'd do it again. I did have two functioning boards at one time but I fried one with a faulty power supply. The unit is boxed up right now but I'll dig it out soon and post a shot of it.
Quote from: FarmerJd on November 02, 2009, 07:15:07 PM
I used a pvc "90" joint and a short piece of 1.5 inch pipe to encapsulate my element end. I am attaching a pic and you can see the pipe on the right side. Since taking this pic I have changed it out with a piece of insulating foam and electrical tape. Just throwing out ideas for you. Sounds like you are a pretty good problem solver yourself. :)
Your bath is similar to my beer kettle and hot liquor tank. Pictures below. You can see what I did with the cord connections. I decided to use the smaller 240 VAC plugs rather than the dryer ones. The HLT is insulated; you might want to do this with your pot as it is so large.
Did you ever try a 2000 Watt 120 VAC element? I've got one but the 1500 seems to work well enough for my size bath. You might consider something like this for control (but for 240 VAC devices):
http://www.rancoetc.com/ranco-etc111100000-digital-temperature-controller010v-output-p-97.html (http://www.rancoetc.com/ranco-etc111100000-digital-temperature-controller010v-output-p-97.html)
You could also mount two 1500 Watt 120 VACs.
I have actually considered installing both elements (120 and 240) so that I could heat faster at times (such as bringing cold milk to 88 degrees-- forever!) but I could also heat smaller amounts slower (like 10-15 gallon batches) that heat too fast with the 240v. Are you suggesting the 2 1500w 120v just because of ease of use or compatibility with a thermostat?
Thanks for the link. I wish I had a little more knowledge of circuit board structure and applications. I am sure I could get lost for weeks tinkering with it. I don't think I will ever insulate the tank because the temperature differential with the room temp is never more than about 25 degrees so there isn't alot of heat flow. I only use it for cheese.
Quote from: FarmerJd on November 02, 2009, 11:59:08 PM
Are you suggesting the 2 1500w 120v just because of ease of use or compatibility with a thermostat?
No. Sometimes 120 vac just doesn't cut it. I use 240 vac elements for brewing beer because I need the power (like you do). I will say that 240 vac near liquid is scary. I have my tuns well grounded and hooked up to spendy gfi breakers. But if one can get away with the lower voltage it is definitely safer and more portable.
You got me interested in taking a closer look at the Ranco controllers as I'd like something that could switch on/off (for heating and cooling) at both 120 and 240. Some of the Ranco spec sheets show 240 vac devices being controlled. It looks like one can also hook up external relay switches. I've got an email in to them to clarify this as none of the spec sheets explain how this is done.
http://www.rancoetc.com/which-etc-model-need-a-6.html (http://www.rancoetc.com/which-etc-model-need-a-6.html)
The external relay idea (if 240 vac devices can't be triggered) might be a good solution for you. It is fairly easy to use a relay. Basically a low vdc signal triggers the relay to turn it on/off. I currently use one for my brew kettle. I built a circuit board (based on a "timer" chip) with a potentiometer so that I don't have to have my element going at full blast all the time. I can turn the knob and control the element to be off or on full or anywhere in between. Here's a picture of the solid state relay and the circuit board. The red light indicates that the board is on while the green light indicates if the relay is on. The relay is attached to a heatsink I got at a used computer store (relays generate a bit of heat).
Hey Micah how about using a bulkhead fitting with a ball valve and hose out the bottom?
Quote from: DeejayDebi on November 04, 2009, 01:46:17 AM
Hey Micah how about using a bulkhead fitting with a ball valve and hose out the bottom?
Do you mean for removing the whey? I think the siphon method will be okay. The fewer holes I have to worry about the better. And I fear the curds would clog the drain hole quite easily unless a ring of some sort were employed.
I took a look at your smoking site and passed it along to a friend of mine who is quite the smoker. We made 40 lbs of Elk landjaeger a couple of weeks ago. Sixty more to go...
All I can say is holy mackeral.
I have so many questions....
I will add that I used the following formula to calculate how much heater I needed in my water bath.
So for me, It worked like this.
I had 100gallons of water. (milk and water bath)
I need that to be able to go from 100 to 124 degrees in 45 min.
So that worked out to
[(100*24)/(372*.75)]X1000=8602watts
That gave me a rough idea of what I needed. So I decided to go with (5) 2000watt heaters. I have 10,000watts of heat being pulled for short periods of time.
I am considering putting my heaters through the walls of my water bath. What fittings, o-rings, sealants etc. did you all use to penetrate the walls of your water bath vessels?
Wayne as a physics teacher I have to take off points because you didn't show your work in that equation. ;D Just kidding but I really didn't follow the math. Here is my math for my tank and pot:
40 gallons of water and milk (24 gallons of milk; 16 of water) = 151 kg liquid with an average specific heat capacity of around 4032 Joules/kg (milk is 3930 and water is 4186) (this doesn't take into consideration the metal in the pot)
raising temp from 31C to 39C (8 degrees Celsius) in 45 min or 2700 seconds
Energy needed = 4032 Joules/kg x 151 kg x 8 degrees Celsius = 4,870,656 Joules
Power needed = 4,870,656 Joules / 2700 seconds
Power = 1804 Joules/ seconds or 1804 Watts
I guess with the steel pot added and the heat lost through convection, radiation, and conduction my setup works out about right because I can turn it on and I don't have to turn it off on a full batch. It takes exactly 45 min to heat it 8 degrees. If I use less milk though I really have to watch it so I really want a thermostat. My problem is that when I have to cool it down I am in trouble.
I figured your setup (wow that's a lot of water!) and got a different answer (but close) than you so I may be figuring wrong.
100 gallons of water and milk = 378 kg liquid with an average specific heat capacity of around 4125 Joules/kg (milk is 3930 and water is 4186) (this doesn't take into consideration the metal in the pot)
raising temp from 38C to 51C (13 degrees Celsius) in 45 min or 2700 seconds
Energy needed = 4125 Joules/kg x 378 kg x 13 degrees Celsius = 20,270,250 Joules
Power needed = 20,270,250 Joules / 2700 seconds
Power = 7508 Joules/ seconds or 7508 Watts
If this is right, you could take out 1 of the elements and probably let it run wide open and have a perfect cook. I still hate thermodynamics. :P
QuoteI am considering putting my heaters through the walls of my water bath. What fittings, o-rings, sealants etc. did you all use to penetrate the walls of your water bath vessels?
My solution was pretty simple: I cut a hole and welded a nut the size of my element on the pot and just used Teflon tape to seal it.
The commercial guys use steam and circulating water jackets, so I'm thinking, why not use a water heater to circulate hot water thru your heating vat? Even a smaller mobile home size heater might work. A relatively simple submersible thermostat would control a low flow pump from the water heater to the vat. Inside the vat would be a coil of copper tubing that would transfer the heat to the vat water. When the vat hits operating temp, the pump shuts off. You could probably even use the thermostat from a a cheap commercial steam tray (EBay) to control the pump. Want to raise the temp 10 degrees over 45 minutes? Set the operating temp on the thermostat, but slow the pump down so it doesn't heat too quickly. I'm sure you guys have a formula for this one. ::)
The plumbing would be easy, and the hot water would always be ready to go. Instead of starting with cold tap water, fill the vat with hot water from the heater. Properly filtered, this could also be a source of instant hot water for washed curd cheeses. Just set the water heater to the target temp and "wash" water is always ready to go. Hmmmm.....
Christmas list just got unmanageable! I really wish I could do what you are suggesting sailor because it would be so much easier to control the temp up or down and the washed curd business is a real headache right now. However, I would have to have a separate cheese making room or facility if I was going to add a heater and a pump and all the hoses. I am going to study on it a while and see how feasible it would be. Good ideas.
Oh yea, there is a formula for that too and it also gives me a headache. :)
Quote from: Wayne Harris on November 04, 2009, 10:03:29 PM
I am considering putting my heaters through the walls of my water bath. What fittings, o-rings, sealants etc. did you all use to penetrate the walls of your water bath vessels?
I had 1" stainless steel threaded half-unions welded on my kettles. Sound easy? Not quite. Hot water heater elements have straight threads and as far as I can tell nobody makes a 1" SS straight threaded half-union; they are all NPT. So I bought a 1" straight thread tap and converted the NPT to straight thread. The elements fit the unions perfectly. I use the washers that come with the elements to finish the seal. No pipe compound or Teflon tape used. One kettle has been in service for over 15 years; the other for 8. I have had no leaks and have not had to replace the elements yet.
Both of these vessels have been employed extensively as brew kettles; that is, they have been used for vigorous boiling of wort.
Unfortunately I don't have my tap on hand to post a picture (or the extra half-unions I bought for future projects) as I've lent them to my brother so that he can craft some brew pots.
This has been my experience. I was wondering how others solved this....;
My bad Wayne; my heating tank is not stainless so I never thought of it being a challenge; i just coated it in automotive paint and I never get the temp very high like you guys do with brewing. I wish it was stainless though; maybe one day. I said I used a nut but it was actually a threaded coupling with straight threads. I had forgotten that I decided to use that to keep the threads away from the weld. A straight threaded stainless coupling would be hard to find.
FarmerJD,
Here is the email thread I had with Ranco.
QuoteI'm interested in the ETC Controllers but I don't know which would be best for my needs. I'd like to be able to control both 120 VAC (12.5 amps) and 240 VAC (10.5 amps) devices (though not at the same time). I'm willing to rewire the unit as needed. I read on the "selector" page that external relays can be employed. However, I don't see mentioned in any of the online pdf manuals reference to doing this. It would be nice to use an external solid state relay to control my device(s) this would simplify my switch over task. So basically I'm looking for a single stage controller that could be used for both heating and cooling and 120 vac and 240 vac. Which controller is best for me?
Micah
QuoteThe ETC-111000-000 controller will run at both 120VAC and 240VAC and will do either heating or cooling. If you needed automatic switch over from heating to cooling, then the two stage controller (ETC-211000-000) would be recommended, though it has lower amperage ratings and an external relay would be needed to drive the loads you have quoted. Either model can drive external relays if needed that can in turn drive the load.
Tim (Ranco)
Quote
So let me get this right. The ETC-111000-000 can run at both 120VAC and 240VAC AND can ALSO drive both 120VAC (12.5 amps) and 240VAC (10.5 amps) devices. It also can drive external relays.
Micah
QuoteYes, it's just a set of dry contacts (a simple relay) so it acts like an on off switch
Tim (Ranco)
QuoteIs there documentation for hooking up an external relay?
Micah
QuoteThere is no specific documentation on connecting an external relay. In the wiring diagrams for the ETC the coil on the external relay would be considered the load.
Tim (Ranco)
QuoteIs the VDC signal selectable (5VDC, 7VDC)?
Micah
QuoteNo, the 0-10VDC is a output that varies according the current temperature reading. at -30F it would be 0VDC, and at 220F it would be 10VDC and would read a voltage in between according to the temperature reading.
Tim (Ranco)
Hadn't actually thought of that, but since the milk doesn't actually touch the vat, stainless would be overkill.
Micah,
Ok so I need this controller and a copper thermal well so that it will be submersible in liquid. So what were you suggesting using the external relay for? Was that for controlling the 240v element if the controller would not do it? It sounds to me like Ranco is saying it will work with out one, right? And how did you set up the potentiometer to manipulate the voltage so that you could control the rate of temperature change? And program it too :o? And interface with your computer? Wow!
One more question: I don't really understand the analog output. Can you explain?
I saw that Ranco also sells the controller used in the Johnson "freezer to fridge" thermostat I just got. I guess I could have put that together too. :-[
Sorry to bombard you. Just ignore if it's too much. Thanks!
Quote from: FarmerJd on November 06, 2009, 08:32:04 PM
Ok so I need this controller and a copper thermal well so that it will be submersible in liquid.
It looks like that will do it.
QuoteSo what were you suggesting using the external relay for? Was that for controlling the 240v element if the controller would not do it?
Yes. It was unclear to me from Ranco's product descriptions if 240v devices could be switched. All the blurbs state "great universal controller for any application where switching 120Volts..." which led me to infer 240v was not supported. The external relay idea was only for if the controller could not switch 240v at the required amperage. This is the case for their "two stage" units.
Quote
It sounds to me like Ranco is saying it will work with out one, right?
Yes.
Quote
And how did you set up the potentiometer to manipulate the voltage so that you could control the rate of temperature change? And program it too :o? And interface with your computer? Wow!
My pot actually doesn't regulate the voltage. I'm cheating and using it to vary how long, over a given period (using a 555 timer chip), the relay is on and off. So if the knob is turned all the way to the left, the element will be off for the period; all the way to the right, it will be on for the period; in the middle, it will be on for half the period; etc.
This circuit board isn't programmable. I have a second microprocessor based board that is.
Quote
One more question: I don't really understand the analog output. Can you explain?
The vdc output is used to switch on/off the on board relay. It varies from 0 vdc to 10 vdc based on the temperature sensor's reading. They are using a thermistor (as opposed to a thermocoupler) and scaling the measured resistance (ohms). This signal can be used to switch an external relay as well. It took me a while to figure out why the signal is not merely on/off. One could also take this signal and given a table or regression formula convert it back to the measured temperature. So it is much more versatile information than just on/off. A practical application would be to take the signal and remotely display the temperature reading. One could also feed the vdc readings taken over time intervals into a computer to monitor/analyze the temperature fluctuation.
It is unfortunate that their two stage units can't handle the amperage we are needing. They must be using different relays for the two stage model; probably due to space requirements.
I'm going to get one of these pups.
Micah
Thanks for taking the time to talk me through that. Thumbs wayyy upppp!
Great idea, Micah
how is it working for you?
I'm thinking about building something like that myself. I was wondering what you used to cut the lid and drill the hole for the heater, also what you used to seal the heater hole so it doesn't leak.
Quote from: Majoofi on February 04, 2010, 10:04:38 PM
Great idea, Micah
how is it working for you?
I'm thinking about building something like that myself. I was wondering what you used to cut the lid and drill the hole for the heater, also what you used to seal the heater hole so it doesn't leak.
The cooker is working out very well. I picked up a Ranco ETC-11000 controller to throttle the heating element. I separately monitor the temperature of the milk. I use an aquarium pump in the water bath to agitate the water in order to avoid stratification.
I used a jig saw to cut the lid and a paddle bit (hole saw also works) to drill the hole for the element. The heating element has a washer on the exterior which provides the seal but I also used a high heat silicone sealant (available at hardware stores) to ensure water tightness. A 1" nut from an electrical tension restrainer is on the inside -- those things that you screw into the knock-outs of a J-box and tighten down to keep the electrical wire secure.
When cooking up 4 gallons of milk (5 could easily be done but I haven't done this amount yet) the most difficult task is removing the whey. The pan is too heavy, using ones finger nails, to remove in order to pour off the whey. I have successfully used a siphon hose with a small stainless steel "bazooka" screen; eventually the screen clogs but by then enough whey has been removed so I can easily lift out the pan.
The "easy-masher" (EM-1) utilizes the bazooka screen size I use:
http://www.ibrew.com.au/html/equipment/Easymasher/EasyMasher.htm (http://www.ibrew.com.au/html/equipment/Easymasher/EasyMasher.htm)
thanks for the quick response.
sounds good. how quickly does the water bath move up in temperature? I was thinking of having a separate hot water source and pumping in hot water, because I thought that if it works well for me I could build the cookers in series and make double or even triple batches.
Quote from: Majoofi on February 05, 2010, 06:13:55 PM
thanks for the quick response.
sounds good. how quickly does the water bath move up in temperature? I was thinking of having a separate hot water source and pumping in hot water, because I thought that if it works well for me I could build the cookers in series and make double or even triple batches.
I start with water warmer than my milk's target temperature because the milk needs to come up to temperature. I'm still experimenting with the system. The 1500w element seems to be enough to get things done in a timely manner. It seems to me that you'll either have to employ a pump or use gravity to move all the water from one vessel to another. I use the heating element to step temperatures when required by a recipe. I'm not sure you could easily do this with the method I think you are describing.
i´m interesting in this , we can continue this ?
i want to post my new system soon
and try with water first
Hi Guys.
Micha,; Can you tell me what you mean by stratification in the bath?
I have built a cooker, and i do not have a pump in the bath (I presume this is to circulate the water)
Ian
Stratification refers to a situation where the heat in your liquid is different from the bottom to the top. Heat rises so if the heat source is near the top, the liquid at the bottom will stay much colder. If the heat source is near the bottom, the natural convection of the heated liquid rising will mix the water and reduce stratification. A pump will do this even better but it is not absolutely necessary unless your heat source is at the top.
Thanks for that.
I Have considered convection and hope it will work ok for me!
Cheers