# Diy Stainless Jacketed Fermenters



## thermo_47 (4/12/12)

It's bloody hot in Brisbane today. As I drink my stout and sit in front of the fan, I thought I'd share an idea I've been mulling over in my brain for a while now...

I welcome criticism and people's opinions, but prefer them to stay constructive!

My basic idea is this: to ferment beer in 50L kegs that are sitting in half a 44 gal drum of water to keep them cool. Nothing new here, but I plan to have a 60L fermenter of water in my fridge kept as cold as possible to circulate into the 44 gal drum to cool the fermenter. This will be controlled by a digital thermostat - STC1000 or I plan to go to the BCS-462 controller soon. I would use either a Sanke Fermenter kit or a 2" Tri Clover barbed fitting with a hole drilled into it for the thermowell on top of the keg.

I reckon this idea works because you're not using ice or 6 different fridges, and your beer is in a strong, lightproof and sanitary fermenter where it's at a regulated temperature.

Problems I can see:
- Cooling power of the fridge/volume of cold water is not enough
- Cleaning those kegs will be tough
- Overflowing the 44 Gal drums and draining water etc if anything goes wrong
- Pumps getting un-primed and not working?
- Obtaining legal kegs...

My solutions/thoughts:
- Instead of using the fridge component, I could use my freezer with heat exchange coils in ice blocks/bowls/something. Only issue there is the cooling water freezing in the coils when it's not pumping.
- Use a submersible pond pump or similar in the bottom of the cut-off 44 gal drum to circulate water from the 44 gal drum through a coil in the fridge/freezer instead of actually pumping the water from the fridge around. Same level in the drum (minus evaporation) all the time then.
- Use radiator coolant/glycol/salt water to cool with so it doesn't freeze in a coil in the freezer - but would that rust pump parts/kegs/go off/smell etc?

What I need everyone's thoughts/expertise on:
- What kinda pumps should I use?
- Can I make the freezer idea work? I like it better...
- What "coolant" should I use?
- Anything else I've missed?

Thank you all for your replies in advance... who knows - if this thing works well it could be a winner for homebrewers everywhere!

Cheers,

Jon


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## tallie (4/12/12)

My initial reaction is that unless you've got the drums sitting in a closed off, well insulated container, it's not going to be very efficient. In terms of energy use, you'd be better off putting the fermenter(s) directly in a fridge/freezer with a temp controller and a 12V fan to circulate the air.

Cheers,
tallie


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## thermo_47 (4/12/12)

Thanks for your thoughts Tallie. My problem is that I want to have 3 or 4 beers fermenting at once, and preferably not 3 or 4 fridges running all the time...

Looking into insulation is a good idea though. Cheers!


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## adryargument (4/12/12)

Upright Fridge/Freezers are not built to deal with that amount of water. In that tight a compartment the freezer will never reach its 'low temp' and burn out the compressor quick smart.
This has been attempted and failed many times by computer enthusiasts looking to run water cooled setups.

The other issue is condensation will start forming on the outside of your drum, constantly.


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## pk.sax (4/12/12)

Chuck a frozen bottle or two in the drum by the side of the keg and forget about the coils. More trouble than you need.

Or just brew weather appropriate brews


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## labels (4/12/12)

Although the idea is good you need to get the maths right. I can't help you here but I'm sure somebody will chip in with enough knowledge to help.

Thing is, you could go ahead and do this which is going to cost time and money to find it doesn't work as expected. If you're like most of us, you will then spend more and more trying to make it work and end up with a white elephant. 

As an example, look at the size of the glycol chilling units just to cool a single six tap font in a hotel, they're friggin powerful compared to a domestic fridge.

=-Steve=-


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## niggles (4/12/12)

Hey Jon, 

Check out my similar attempt from a few years back [topic="29763"]here[/topic] - it worked quite well. 

My objective was to ferment ales as well as lagers simultaneously from one temp-controlled fridge. Obviously the lager temp was controlled and the ale cooling bath temp "coupled" to that.

Temp control of the external fermenter could definitely be achieved with an STC activating a pump, the main issue to solve is preventing freezing of the coil as you've identified. I'd be careful with glycol as it's messy/toxic, but it certainly has advantages in terms of allowing precise control whilst not freezing.

One potential solution to solve both these issues might be to have a suitable fluid (glycol) contained within a continuous loop instead of the recirculating bath. The loop (e.g. plastic hosing) could be "wrapped" around the fermenter, and the whole thing insulated to minimise heat conduction to the atmosphere. Even though the thermal conductivity & heat transfer properties of plastic/flexible hosing aren't ideal, I think it could work assuming the insulation is effective. 

OR have a closed loop, with one heat exchanger in the freezer, and one sitting in a bath around your fermenter. Food for thought....

Cheers,
Niggles.


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## Punkal (4/12/12)

You want one of these...

Aquarium Chiller

They are used to keep aquariums at around 26-27c but I think they can go lower.

I have the next size up for my SW aquarium, a little expensive new but you could probably find one cheap second hand (a lot of people get out of SW aquariums around 6-12 months in).

Its funny how much aquarium and home brew equipment are similar. I tried to take a specific gravity reading with the SW refractometer the other day.


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## QldKev (4/12/12)

Punkal said:


> You want one of these...
> 
> Aquarium Chiller
> 
> ...



Do you think it would have the grunt to go a lot lower in temp? Probably get away with an Ale, but not sure about Lagers.


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## Maheel (4/12/12)

i am considering this then i can sit inside and drink beer with my fermenters ...


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## winkle (4/12/12)

Maheel said:


> i am considering this then i can sit inside and drink beer with my fermenters ...


After today, I think you've got the right idea.


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## thermo_47 (4/12/12)

Ha! Yeah I've looked into coldrooms, sheds converted into coldrooms with an air conditioner, and all sorts... even those aquarium chillers! At $300+ a go I'd wanna hear if they definitely work... and then really my issue is to have INDIVIDUAL control of each fermenter. So at $300 per fermenter, I'd just run separate fridges and pay the power bill. 

Obviously the "perfect" setup is a full glycol system with jacketed stainless fermenters, but is super expensive. The cheap option is to use ice - inconsistent and a lot of work to keep up. I'm hoping that somewhere in between is my little concept... glad to see others have been there before!

Based on Niggles' setup, I'm gonna have a go at my idea, but head towards the coil in the freezer setup. Start with one and see how I go. I think that running ice water as coolant and having larger diameter coil like 1/2" will help it not to freeze. Once I set it all up I'll post some pics.

Just for reference, I'm only thinking all of this for fermenting ales between maybe 16 and 25C. I have another fridge for crash chilling etc.

Appreciate everyone's thoughts!

Jon


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## labels (4/12/12)

Propylene glycol is non toxic but expensive. Also used in medicines such as cough syrups it's inert in the body (although can a laxative effect in larger doses) Ethylene glycol as used in your car is toxic.

I have a font cooler using a saturated solution of water and salt with a submersible salt water aquarium pump. Fully saturated salt water can go to -24C before it freezes. Obviously, use materials that are not affected by the corrosive nature of the salt solution, plastic pipes, 318 grade SS etc.

-=Steve=-


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## thermo_47 (4/12/12)

... and if I leave my fridge running all the time so that the freezer keeps cold, I can use the fridge part to store hops etc or cold condition kegs!


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## shaunous (4/12/12)

Have you got a pool, water tank or another large water source close to where you would want the fermenter. If your only wanting around the 18degree's mark, my neighbours pool sits at that close to year round, and just as a guess, water tanks would be pretty close also. The more water you have, the more it will effectivley cool, the more even the temp you will keep. You could pump pool/water tank water around the fermenter and back into the pool/water tank, effectively using it as a cooler.

Wont work for everyone, including me as I dont have a pool or tank, but in my neighbours case would work perfect. Small directional drills use this 'bush mechanic's' way to cool there hydraulic systems, if they dont have a creek/river real close to submerge the hydraulic cooler in, they throw it in an open top 44gal drum of water and pump from the nearest creek/river they have.

Then just use your fridge for lagers.


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## thermo_47 (4/12/12)

Mmmm good call, but no pool 

And no lagers


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## thermo_47 (4/12/12)

In the freezer scenario, I could always run coolant through something like this:

http://www.ebay.com.au/itm/NEW-Black-Alumi...#ht_3985wt_1139


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## beerbrewer76543 (4/12/12)

Your initial idea will use more power than individual fridges. It's all about heat gain from the surrounding environment. Unless you insulate those 44gal drums they will pick up heat and have your liquid chiller running flat out all the time.

Some options I envision:
1. Multiple fridges and STC1000s - will allow temp ramping, diacetyl rests and crash chilling
2. Chest freezer and STC1000 - large temp controlled space for multiple fermenters
3. Cool room - build from second hand fridge panels and an AC unit
4. Glycol system and insulated fermenters


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## Punkal (4/12/12)

I was not able to find any references for the aquarium chillers sorry but I did have a idea. 

I could use my aquarium chiller set to minimum to cool the water going to my immersion chiller (need to upgrade it, its not good enough) and give it a little boost especially on a hot day when my tap water is on the warm side (the fish will be ok for a little bit).


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