Author Topic: Utility Sink Vat  (Read 8602 times)

mjr522

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Utility Sink Vat
« on: February 26, 2013, 04:00:41 AM »
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.
« Last Edit: February 26, 2013, 05:10:42 AM by Mike Richards »

BobE102330

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Re: Utility Sink Vat
« Reply #1 on: February 26, 2013, 05:40:49 AM »
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.

Offline Tiarella

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Re: Utility Sink Vat
« Reply #2 on: February 26, 2013, 12:27:55 PM »
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.

mjr522

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Re: Utility Sink Vat
« Reply #3 on: February 26, 2013, 02:45:17 PM »
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.

mjr522

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Re: Utility Sink Vat
« Reply #4 on: February 26, 2013, 02:46:34 PM »
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.

WovenMeadows

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Re: Utility Sink Vat
« Reply #5 on: February 26, 2013, 03:30:59 PM »
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 for the heat source and this thermostat controller 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.

mjr522

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Re: Utility Sink Vat
« Reply #6 on: February 26, 2013, 04:59:43 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.

WovenMeadows

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Re: Utility Sink Vat
« Reply #7 on: February 26, 2013, 07:30:48 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.

High Altitude

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Re: Utility Sink Vat
« Reply #8 on: February 26, 2013, 10:02:58 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!

mjr522

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Re: Utility Sink Vat
« Reply #9 on: March 03, 2013, 02:57:33 AM »
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.

Offline Tiarella

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Re: Utility Sink Vat
« Reply #10 on: March 03, 2013, 05:49:23 AM »
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

mjr522

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Re: Utility Sink Vat
« Reply #11 on: March 03, 2013, 05:24:01 PM »
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.

mjr522

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Re: Utility Sink Vat
« Reply #12 on: March 04, 2013, 03:46:32 AM »
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.

Offline Tiarella

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Re: Utility Sink Vat
« Reply #13 on: March 04, 2013, 09:59:50 PM »
Cool!  Keep us posted with photos when you do the new drain system.   :D

Tom Turophile

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Re: Utility Sink Vat
« Reply #14 on: March 06, 2013, 04:01:05 PM »
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.