Author Topic: Polycarbonate cheese vats  (Read 7095 times)

Geodyne

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Polycarbonate cheese vats
« on: September 07, 2013, 05:23:52 AM »
I've been trying to think of ways to create a square cheese vat. So far the stockpot double-boiler approach has worked for me, but limits me to 10-litre batches and I'd like to be able to work with 20-litre batches. I've seen some polycarbonate cheese vats online, at http://www.cheesemaking.com.au/tubs-and-pot-sets.

The retailers claim that these insulate the milk well which is great, but polycarbonate conducts heat poorly so I wonder whether such a vat would make temperature increases difficult. Has anyone used similar equipment and be willing to share insights?

Spoons

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Re: Polycarbonate cheese vats
« Reply #1 on: September 07, 2013, 07:24:34 AM »
This is my current setup. I switched from a plastic pan to a 24 gauge stainless steel pan. Much better heat conductivity. The 15cm (6") full pans can safely do 16L, the 20cm(8") pans can safely do 20L batches. Hope this helps  ^-^




Geodyne

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Re: Polycarbonate cheese vats
« Reply #2 on: September 07, 2013, 08:19:32 AM »
That's really helpful, thanks Spoons. Picking up a stainless bain marie pan was another thought I had but I wasn't sure they'd have enough capacity. It sounds like I want to be looking out for an 8" stainless pan and something to make a water bath for it.

How do you increase heat? Just add more warm water?

Spoons

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Re: Polycarbonate cheese vats
« Reply #3 on: September 07, 2013, 01:41:14 PM »
There are many ways to increase and maintain heat, but this is the best way:

http://www.waterbaths.com/products/sousvide_products.html

It's a bit expensive, but if you're into sous vide cooking, then it's a huge investment for both your kitchen and cheese making hobby.

here's a few more links to help you build your pan-based vat:

8" Stainless full pan http://www.webstaurantstore.com/vollrath-90082-super-pan-3-stainless-steel-full-size-anti-jam-steam-table-pan-8-deep/92290082.html

Carlisle 26x18x9 Food Container http://www.webstaurantstore.com/clear-carlisle-1062207-storplus-food-storage-box-26-x-18-x-9/700182609CL.html

The stainless steel full steam pan fits in the plastic container. Just add a baking wire rack to circulate water underneath the pan, or buy 2 x 1/9 stainless steel food pans (4" deep) so you can fit all 3 stainless pans on the top ledge of the plastic container (you'll then have a 3" clearing underneath your pan).

tnbquilt

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Re: Polycarbonate cheese vats
« Reply #4 on: September 07, 2013, 04:48:00 PM »
Electric turkey roaster, the best home cheese vat ever. Double wall, removable pan, and it's electric. You can buy 18 quart or 22 quart. They are everywhere around Thanksgiving to Christmas, but after that they are hard to find except on the internet.

mjr522

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Re: Polycarbonate cheese vats
« Reply #5 on: September 07, 2013, 07:59:03 PM »
If you're just looking for vat ideas, an electric turkey roaster with a controller on it is pretty good.  I've been pleased with my utility sink vat.  I'll update that thread later today with a report on most two most recent makes (an 8 and a 12 gallon batch).

Offline NimbinValley

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Re: Polycarbonate cheese vats
« Reply #6 on: September 07, 2013, 11:18:48 PM »
If you are worried about heat transfer through plastic you could always opt for a immersion heater that you sit in the milk to heat it.  They can be a bit expensive but do a great job.  You could even make one up of copper pipe and run hot water through it.  It would be fine for small volumes I would think.

NV.

Spoons

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Re: Polycarbonate cheese vats
« Reply #7 on: September 08, 2013, 12:51:40 AM »
I agree that turkey roasters with a PID are great but the cutoffs and overshoots are always a little off. To tell you the truth though, I've always wanted to join in the fun and build a PID setup.

Here is an example of the cutoffs and overshoots:


mjr522

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Re: Polycarbonate cheese vats
« Reply #8 on: September 08, 2013, 02:07:35 AM »
A well designed cheese vat wouldn't have that problem.  As I've discussed elsewhere, there's no reason to have an overshoot in a cheese vat.  Typically the overshoot in a feedback control for a mechanical system is a result of momentum, but there's no momentum in thermal systems.  What happens in cheese vats is too much energy is produced in whatever is surrounding the milk and then the temperature goes too high.  If the P is turned down, the D is turned off, and the I is adjusted correctly, you can have a response that doesn't get to the set temperature quite as fast, but doesn't overshoot at all.  Most of us aren't patient enough to make that happen, and instead tolerate a 1 degree overshoot (since, who trusts that their thermocouple/thermistor is actually that precise, anyway?).  I suppose I wonder what other systems (besides a PID) people use that reach the set temperature as fast and have as little overshoot.  Manual control of the temperature means slow rise time or overshoot, as well (unless you just pull your pot of milk from the hot water bath the second it reaches temperature).

Spoons

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Re: Polycarbonate cheese vats
« Reply #9 on: September 08, 2013, 02:47:36 AM »
Mike, you're right that as of now, the PID inspired vat is the best, most accurate and affordable option. I'm not contesting that at all!

Geodyne

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Re: Polycarbonate cheese vats
« Reply #10 on: September 08, 2013, 10:17:05 AM »
Thankyou everyone. I'm so pleased I asked, there are some wonderful ideas here.

I can see how convenient a turkey roaster would be but my preference is to try to not be too reliant on electricity. Turkey roasters are much less common in Australia than in the US. I don't think I've seen one in Australia or the UK and postage would be prohibitive.

Spoons, thankyou. A google tells me that I can pick up appopriate 8" stainless bain marie pans for not a lot of money. That and a water bath (maybe in an insulated cooler?) or a direct immersion heater might do the trick (thanks NVD for that thought) although I'd worry about cleanliness.

Mike, I covet your sink vat. Maybe one day.

Geodyne

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Re: Polycarbonate cheese vats
« Reply #11 on: September 09, 2013, 12:05:56 AM »
Hm. Having said I wanted to avoid an all-electric solution, I wonder how readily controllable the temperature is on a bain marie.

Spoons

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Re: Polycarbonate cheese vats
« Reply #12 on: September 09, 2013, 12:25:42 AM »
I considered those for quite a while! It's a great option. You'll need a PID controller, I believe those steam table have a minimum of 140F temp.

Geodyne

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Re: Polycarbonate cheese vats
« Reply #13 on: September 09, 2013, 01:04:14 AM »
The ones I'm looking at claim to do 0-90C or 20-90C (68-194F), so well below 140F. But I suspect a PID controller would make for better temperature regulation.

Geodyne

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Re: Polycarbonate cheese vats
« Reply #14 on: September 21, 2013, 02:34:27 AM »
After due consideration, I bought an electric bain-marie. One session of trying to keep water warm in the kitchen sink made me realise that that was more wasteful of electricity than a small heating unit.

This bain marie is insulated and does wet heat, which is great. The main reason I bought it however, is that it comes with an 8" 1/1 tray included, which gives me capacity to work with 26 litres, or 7 gallons of milk at a stretch - but 6 gallons comfortably. Most other benchtop bain maries will only take 6" trays.

There are two small drawbacks to it: it doesn't have a tap for draining whey (but I love the siphon idea so I'll try that) and the thermostat runs from 30C (86F) to 110C. The low end is a little higher than I'd have liked but I figure if I want milk at 26C I'll heat the water to 30 and allow everything to equalise. If I want to hold at 26C it's easy to turn the unit off.  If I find that the heating element is uneven I can add a PID in the future.

Best of all, it's cost me $200.