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GENERAL CHEESE MAKING BOARDS (Specific Cheese Making in Boards above) => EQUIPMENT - Making Cheese => Topic started by: Mike Richards on February 25, 2013, 10:00:41 PM

Title: Utility Sink Vat
Post by: Mike Richards on February 25, 2013, 10:00:41 PM
I'm working on a cheese vat using a stainless steel utility sink.  The one I've got is 18"x18"x12" and will take about 15 gallons (I haven't yet filled it to capacity).  I heat the vat with rubber heating pads.  Tonight I filled the vat with water and ran the autotune on my controller.  It seems to work pretty well.

[img width= height= alt=utility sink vat showing controller.]https://sphotos-b.xx.fbcdn.net/hphotos-ash4/387526_303187653140015_1560596909_n.jpg[/img]

The brown line going into the water is a waterproof thermocouple.  This image shows the vat with 4 gallons +1 quart of water.  I will continue making 4 gallon batches even though I've got the larger capacity until I can get/make a bigger mold (or stackable molds) and a press that will accommodate more cheese.

I initially ordered a 6"x18" heating pad.  It was not one of my finer reasoning moments.  I thought, "oh, the vat is 18" so I can get an 18" pad for the bottom...".  However, the bottom has legs in the way. 

[img width= height= alt=large pad angled across the bottom]https://sphotos-b.xx.fbcdn.net/hphotos-ash3/541605_303198313138949_1309383111_n.jpg[/img]

Turns out that heat doesn't transfer very well through polymers.... After burning up that heating pad and making my house smell a little funny (I watched it the whole time, so it wasn't too dangerous--mostly disappointing), I figured I'd need something different.

Once I got over the disappointment, I ordered an assortment of pads (because the ones I really wanted had a 5 week lead time).  I've got 2 5"x8"s, 1 3"x6" and 1 2"x10".  Each are 10 watts/in^2 for a total of 1180 watts.  Here's how they are arranged, all on the bottom:

[img width= height= alt=bottom of vat showing pad arrangement]https://sphotos-b.xx.fbcdn.net/hphotos-ash3/574995_303187656473348_1923952250_n.jpg[/img]

I have a few things that I'm concerned with.  The first is that the pads run at about 90 F hotter than the water temp.  I'm a little worried that the heat transfer into the milk will be too fast and I'll get some scalding going on.  You can see the accumulation of bubbles in the water, which was not stirred at all during heating, in the next image.  I'm hoping to be able to compensate for that by stirring when I actually make cheese.  I'll report on that after I've tried.  Another concern that I've got is the drain:

[img width= height= alt=picture of drain]https://sphotos-b.xx.fbcdn.net/hphotos-ash4/312461_303187649806682_1232721355_n.jpg[/img]

I'm sure this is a potential contamination site.  I can remove and clean the drain and gasket every time I make cheese, but I'm lazy and would prefer it if there were a less labor intensive way to sanitize it.

What are your thoughts and reactions?  There's more story/details to tell, but I thought I'd put out this much and see if anyone is interested in knowing more.
Title: Re: Utility Sink Vat
Post by: BobE102330 on February 25, 2013, 11:40:49 PM
Ninety degrees delta seems like it will take some vigorous stirring during the heating phase to keep from scalding. Will you add insulation to the outside to help maintain the temperature? 

Do you have a ramp soak pid? That will modulate the power delivered to the heaters to maintain a set rise time. There are controllers available that allow RS485 programming so you can store various cheese profiles and load the one you're making.

I'm making a food tray warmer vat but bought the manual programable version of the ramp soak PID. Oops. Hoping to learn from your experience.  No idea about the drain.
Title: Re: Utility Sink Vat
Post by: Tiarella on February 26, 2013, 06:27:55 AM
Hey Mike, ALWAYS interested in seeing more inventiveness!  Have you looked online to see if there have been any drain plug inventions that are more sanitary or easy to sanitize?  I wonder whether you could create one although my initial wondering about rubber got cast aside in concern about the milk fat interacting with it badly.
Title: Re: Utility Sink Vat
Post by: Mike Richards on February 26, 2013, 08:45:17 AM
Bob--I've been thinking more about that temperature difference and have convinced myself that it isn't actually that big.  The 90 F is the difference between the water temperature and the under side (the side exposed to the air) of the heating element.  Because the majority of the heat is being dumped into the water, the sink heater interface must have a steeper gradient than the heater air interface, which means that the temperature the water sees should be lower than the temperature at the back of the element.  Still,  I'll be stirring once I get milk in there.

I intend to add insulation to the sides (and the bottom once I'm convinced that won't cause the heating elements to overheat).  I also plan on constructing a styrofoam "lid" that I can put over the top.

My controller doesn't have a ramp soak function.  I will upgrade to one that does if I find this too cumbersome/insufficient.  I don't mind the idea manually moving the temperature up in intervals, but I haven't actually had to do it yet--I might mind a lot once I actually have to do it.
Title: Re: Utility Sink Vat
Post by: Mike Richards on February 26, 2013, 08:46:34 AM
Tia--I haven't looked for sanitary drain solutions.  To be honest, it hadn't yet occured to me that that would be something I could look for.  I'll do so some time today.
Title: Re: Utility Sink Vat
Post by: WovenMeadows on February 26, 2013, 09:30:59 AM
I use a regular deep kitchen sink (when making one pot) or a large Igloo cooler (when making 2 pots) as the "vat", and then use  this bucket heater (http://www.amazon.com/MARSHALLTOWN-Premier-742G-Bucket-Heater/dp/B000BDB4UG) for the heat source and this thermostat controller (http://www.beveragefactory.com/draftbeer/keg-equipment/thermometers/A419ABG-3C___9161.shtml) to control the heat. However, I will say that it does not really heat the water quick enough for the high-temp Alpine and Italian cheeses, though it will maintain those temperatures once there. I usually wind up removing some water and adding it boiling water when I am "scalding" the curds for those types. Nor do I use it to heat the milk initially, that is done on the stove. Not as complicated (initially) as a PID controller, just plug-and-play.
Title: Re: Utility Sink Vat
Post by: Mike Richards on February 26, 2013, 10:59:43 AM
WovenMeadows--if I understand correctly, you are using the sink and the cooler as the hotwater bath and putting a pot of milk into the bath.  Is that right?  My goal with this sink is to put the milk directly into it and skip out on the water bath completely.  If it works, I won't have to heat any water--just the milk.  That will allow me to use a smaller heat source for the same amount of milk.
Title: Re: Utility Sink Vat
Post by: WovenMeadows on February 26, 2013, 01:30:48 PM
WovenMeadows--if I understand correctly, you are using the sink and the cooler as the hotwater bath and putting a pot of milk into the bath.  Is that right?  My goal with this sink is to put the milk directly into it and skip out on the water bath completely.  If it works, I won't have to heat any water--just the milk.  That will allow me to use a smaller heat source for the same amount of milk.
Ah! Didn't catch that the first time. Makes much more sense now.
Title: Re: Utility Sink Vat
Post by: High Altitude on February 26, 2013, 04:02:58 PM
Looking forward to seeing pics of your first make in the VAT, when things are squared away!  I'd think that if you're letting a sanitizing solution sit in the VAT prior to the make, there shouldn't be a problem (lazy or not).  Making my first Jarlsberg today...woo hoo!
Title: Re: Utility Sink Vat
Post by: Mike Richards on March 02, 2013, 08:57:33 PM
I made a Monterrey Jack in the sink today.  The sink worked perfectly (though the drain was an issue...).  It took about 30 minutes to get the 4 gallons + 1 pint from 48 F to 88 F.  I stirred a lot at first and then decided to see what would happen if I didn't stir as much.  There was no scalding and the milk seemed to heat up very evenly (which I say because when I did come back after letting it heat on its own, and stirred it, the temperature didn't really fluctuate much).

The problem with the drain is the rubber.  I'm not sure if it's just the gasket between the drain and the sink or also the stopper.  The problem is that the rubber discolored some of the curd and gave it a "rubber" flavor.  I pulled out all the pieces I could see that were discolored.  Hopefully the flavor will not have spread into the rest of the cheese.  We'll see.

So, now I need to find an alternative to the drain I've got right now.  I could replace the rubber gasket with a food grade sealant (though, they are only rated for "incidental contact"), but that still leaves me with the plug.  I don't really need the drain since I'm just draining into a bucket.  If I could find a food safe plastic plug to simply plug the hole where the drain is currently installed, that would be ideal.  Any suggestions would be appreciated.

Here are a couple of pictures from today's make:

[img width= height= alt=covered sink during sanitizing]https://sphotos-a.xx.fbcdn.net/hphotos-ash4/426528_305556669569780_1144061258_n.jpg[/img]

I sanitized the sink with hot water.  I made a lid out of a piece of styrofoam.  I was going to insulate the sides with the same stuff, but I couldn't get it to work they I wanted.  I'll keep working on that.

[img width= height= alt=heating the milk]https://sphotos-a.xx.fbcdn.net/hphotos-prn1/542855_305556666236447_87909298_n.jpg[/img]

Heating the milk...

[img width= height= alt=drain plug]https://sphotos-a.xx.fbcdn.net/hphotos-prn1/555231_305556672903113_1520150268_n.jpg[/img]

You can see the rubber drain plug, and some curd bits in the down by the gasket.

[img width= height= alt=gasket]https://sphotos-b.xx.fbcdn.net/hphotos-prn1/13158_305556716236442_541742163_n.jpg[/img]

Notice how much curd got stuck down there.

[img width= height= alt=hole]https://sphotos-a.xx.fbcdn.net/hphotos-ash3/733873_305556709569776_2012627404_n.jpg[/img]

I just need to find a good way to plug this that won't affect the cheese.
Title: Re: Utility Sink Vat
Post by: Tiarella on March 02, 2013, 11:49:23 PM
Mike, that looks great!  I wonder if you could use a food grade piece of plastic cut to the dimension of the flange and use a brace with threaded rod and nut on the underside to pull it tight against the flange.  To make it further water/milk tight you could either use a food grade gasket material that IS meant to have regular food contact OR put a bit of lard of butter on both sides of the join before tightening.  I wish I could show you in my head what I mean but if it doesn't make sense I'll draw it out, photograph it and post it.  I'm happy for you about how well this project looks like it's doing!   :D
Title: Re: Utility Sink Vat
Post by: Mike Richards on March 03, 2013, 11:24:01 AM
What you've described makes perfect sense (assuming I'm thinking of the same thing :) ), and it is what I will try after I try using the food grade rtv to replace the gasket and a hard plastic stopper to replace rubber stopper.  I'm just thrilled that this has worked as well as it has so far.
Title: Re: Utility Sink Vat
Post by: Mike Richards on March 03, 2013, 09:46:32 PM
Okay--after doing a little research, I ended up buying a 6"x6"x1/8" sheet of silicone rubber (food grade, odorless, tasteless) from which I'll cut out my own gasket.  I also got a plastic stopper.  I'll report on how these work once they arrive.  In the meantime, I'll reconsider how to insulate the sides.
Title: Re: Utility Sink Vat
Post by: Tiarella on March 04, 2013, 03:59:50 PM
Cool!  Keep us posted with photos when you do the new drain system.   :D
Title: Re: Utility Sink Vat
Post by: Tom Turophile / CheeseStud on March 06, 2013, 10:01:05 AM
Great ideas.  I was thinking about adapting this to also use for sous vide -- the wattage is the same that I would use -- but 30 minutes is a long time to warm up 4 gallons 40 degrees, considering that in SV I would need to get to at least 124 (and as high as 180) and the extended SV cooking time.

For cheese, though, it is more practical, I'm just hoping to kill two birds with one stone.
Title: Re: Utility Sink Vat
Post by: Mike Richards on March 06, 2013, 10:39:03 AM
I still need to insulate the vat, which might decrease the time a little (though I'm not sure it will do much--most of the time the milk is below room temperature and insulating will actually prevent heat from entering the milk from the surrounding air).  I'll be working on that tonight and will try to report on what affect, if any, it has when I make cheese again this Friday.  The best way to speed up the heating, with my design, would be to add another heating pad.  The problem, then, is how many amps can your circuit take?  I'm pretty close to the limit on mine with 1180 W.

Unless you are making really big sous vide meal, this might be overkill.  The 4 gallons isn't very deep in this sink and, from what I understand, sous vide should have the food pretty well submerged.
Title: Re: Utility Sink Vat
Post by: BobE102330 on March 06, 2013, 10:52:57 AM
Tom,

I think you would get faster heating times if you enclosed the sink in an insulated box and heated with the insulated top on.  (Mike, I think you'll gain more from keeping all the heat generated in proximity of the vat than you would from allowing room temp air to circulate.) You could also add more heaters, on a separate SSR with a switch to set for sous vide or cheese making.  All heaters on for sous vide, some heaters on for cheese.  As long as you don't have anything else on the circuit you can go to 1800W on a 15A circuit or 2400W on a 20A circuit.  Most hair dryers these days are pushing 1800W.

My concept for insulating the vat is to build a box similar to a vanity around the sink with foil lined insulation facing the heat, but not in contact with the heaters.  Reflect as much radiant heat back as possible, minimize air circulation.  I'd raise the bottom insulation to within a few inches of the sink and allow the drain to penetrate. 

There's my two cents if you think its worth that much.  ;)
Title: Re: Utility Sink Vat
Post by: Mike Richards on March 06, 2013, 11:33:41 AM
Thanks for your thoughts, Bob.  I'm getting some of the radiant heat insulating bubble wrap today.  I'll start by just wrapping the stuff around the sides and see what happens.  A boxed enclosure with no contact would experience less heat transfer, but if I can be satisfied with just wrapping it, that'll be easier.  I don't have a specific plan on insulating the bottom.  I need to see how doing so increases the temperature of the elements.  I don't think it will make a big difference, but I'm hesitant to just through some insulation on them without watching them pretty closely.
Title: Re: Utility Sink Vat
Post by: BobE102330 on March 06, 2013, 12:02:19 PM
At first I thought of melting plastic, then realized that it is a specific product. Leave some space between the heating elements and the wrap, otherwise the foil layer will conduct heat and potentially melt the bubbles.

http://www.energyvanguard.com/blog-building-science-HERS-BPI/bid/29497/The-Foil-Faced-Bubble-Wrap-Sham-Understanding-Radiant-Barriers (http://www.energyvanguard.com/blog-building-science-HERS-BPI/bid/29497/The-Foil-Faced-Bubble-Wrap-Sham-Understanding-Radiant-Barriers)
Title: Re: Utility Sink Vat
Post by: Tom Turophile / CheeseStud on March 06, 2013, 12:14:31 PM
Absolutely something this size would be overkill for SV; I would downsize this unit if I wanted to do both.  Using those heating pads/strips is something that I haven't seen.  I've only seen ones using cheap immersion heaters -- which wouldn't work for cheesemaking, unless you use the double-boiler method.
Title: Re: Utility Sink Vat
Post by: Mike Richards on March 06, 2013, 12:58:28 PM
Bob--I'm not worried about the bubbles around the side melting because the temperature on the side doesn't ever get above the milk temperature, which should remain below the melting temperature of the plastic.  I wouldn't want to put this stuff on the bottom without spacers because the elements might melt it. 

I read the article.  It was interesting to see the author's thoughts and the comments by the other readers.  The advertised benefit for home insulation is a reduction in radiant heat loss/gain.  I'm less worried about radiant heat loss than I am about loss to the air through free convection, though wrapping the vat with a few layers of the bubble wrap should reduce both as each set of bubble presents an air layer through which the heat must transfer.

Tom--the heating pads are cool, but they are a lot more expensive than an immersion heater in terms of price per watt.  http://www.omega.com/ppt/pptsc.asp?ref=SRFR_SRFG (http://www.omega.com/ppt/pptsc.asp?ref=SRFR_SRFG)  The $22 at the top is the price for a tiny one, scroll down to see what you can get and examples of how much they cost.
Title: Re: Utility Sink Vat
Post by: Tom Turophile / CheeseStud on March 06, 2013, 01:13:45 PM
Thanks -- I had meant to ask you about the cost.
Title: Re: Utility Sink Vat
Post by: Mike Richards on April 19, 2013, 04:25:00 PM
It's taken me a long time to report on this.  I've used the vat a number of times now.  I make a little progress in improving it now and then.  I did get the silicone rubber.  It worked well, though I think I'd getting something a little thinner next time--1/8" was a little thick.  After trying a few different options, a friend at work suggested what appears to be a great solution to the draining issue: a sheet of perforated stainless steel.

[img width= height= alt=perforated stainless steel holding curd while allowing whey to drain.]https://sphotos-a.xx.fbcdn.net/hphotos-ash3/603849_326762490782531_1720286891_n.jpg[/img]

[img width= height= alt=ditto]https://sphotos-a.xx.fbcdn.net/hphotos-ash3/563610_326762494115864_875634848_n.jpg[/img]

I push the sheet down on one side of the vat and then slide it across the bottom, pushing the curd away from the drain.  Then, I tilt the sheet up (from the position shown) and pull the drain.  The whey drains, the curd stays.  I'm pleased with it, though I've only used it once so far.
Title: Re: Utility Sink Vat
Post by: CheeWilly on April 19, 2013, 11:01:19 PM
Mike,
You could use the spray foam insulation that is used to fill cracks to insulate the sink.  I would only do the sides if you o use it and would stay away from the bottom where the heating elements are so you can change them out if needed.  The foam will take some technique to smooth it out, but it is very doable.
Title: Re: Utility Sink Vat
Post by: Mike Richards on April 19, 2013, 11:10:49 PM
Thanks for the thought--at some point I hope to add elements to the sides as well so I can do larger batches.  I think I can do about 8 gallons with my current set up, but will need more heating elements to get larger batches up to temp fast enough.  Because of that, I don't want to put any permanent insulation on the sides...
Title: Re: Utility Sink Vat
Post by: High Altitude on May 05, 2013, 01:34:04 PM
That looks awesome Mike!  Glad to see your efforts in this VAT fine-tuning process are working :-).  Great job, and I look forward to seeing your LARGE cheeses in the future.  Mine will remain in the 2 lb range I'm afraid...but at least I get to make them more often that way!
Title: Re: Utility Sink Vat
Post by: Alpkäserei on May 17, 2013, 09:36:42 PM
When I first saw the pictures, I thought that was a steel screen. inside, I was screaming in terror. My life had been ruined.

Then I read it was perforated steel. I breathed a deep sigh of relief, and things returned to normal. All is well.

That's similar to how we retrieve curd, only instead of a steel sheet we use the cheesecloth and a thin piece of spring steel.

Nice looking setup, hope it works well for you.

Title: Re: Utility Sink Vat
Post by: Mike Richards on May 19, 2013, 03:15:42 PM
Thanks, guys.  Alp--I had initially envisioned making a steel frame and putting cheese cloth over it, but a friend of mine asked, "why don't you just use perforated stainless?"  To which I replied, "They make perforated stainless sheet?"  Unfortunately, I haven't been able to make any cheese for a few weeks now, and won't be able to until August.  I look forward to getting back into it.