Internal chilling coil for Sanke fermenters

[Breadontap]

So I have been looking into diy glycol chillers. I have also been using a 1/4 bbl pony keg for fermenting 5 gallon batches. I'm looking at getting a 1/2 bbl keg for 10 gallon batches. The issue is the space consumed with the Sanke fermenters. My current 1/4 bbl doesn't fit in my DIY ferm chamber made from a gifted mini fridge.

So this bring us to the internal coil. I've seen the DIY jacketed glycol fermenter from BYO and I'm glad a fellow Okie has the skill, effort, and resources to make that build. I on the other hand am less skilled and motivated to make such a system. I tested the hypothesis if twisting copper tubing to be able to fit inside a Sanke keg without having any soldered or compression fitting joints.

If you google "bending copper tubing", you will see a fella that fills his tubing with salt then bends a fairly sharp radius coil. I have recently upgraded from a immersion chiller to a CFC. I thought I would borrow a few feet and give it a try.

It actually worked! I filled the tubing best I could, there was some moisture that created a small void and allowed a slight kink but it still allows fluid to flow smoothly.

View attachment 195459

View attachment 195460

How did I do it you might ask. I used 3/8" copper tubing. Fill the tube with salt. Vibrate, shake, whatever to completely fill the tube. Crimp the ends then use a bar to make the initial bend. I used the spear from a Sanke. FYI, if you use the spear you diameter of the U bend will be just a little too big to fit through the Sanke mouth. Once the bend is made you have two pieces of copper pointing up at you. Just twist the tubing around each other until you have a long enough twist to reach the bottom of the Sanke.

I have yet to actually perform the entire build for a couple of reasons. I don't have a 1/2 bbl keg to ferment in, and I don't have a glycol chiller.

The plan is to do like many and use a oversized undrilled bung. Drill an inlet, outlet and hole for airlock. If there is room for a thermowell I will add that as well. I don't think there will be enough room for all of them.

In the end there will be a internal seamless chilling coil that will fit inside the Sanke without modifying the Keg. This should allow for the greatest possible efficiency for cooling and much cheaper than jacketing. I believe 6-8' if copper tubing will do it. Maybe 10'. If anyone beats me to this build please update the thread.


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[WPStrassburg]

You're not going to want copper in the fermenting beer. You need SS tubing if you're doing and internal coil.

 

[Breadontap]

I'm sure you could still do it with SS. What chemical reaction would happen with if you used copper? Many people use it in other parts of the brewing process.


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[DrunkleJon]

From http://byo.com/stories/projects-and-equipment/item/1144-metallurgy-for-homebrewers

Copper
Copper has the highest heat conductivity, is easy to form and was traditionally used for making the brewing kettles or “coppers.” Copper can be readily soldered, brazed and welded with the proper equipment. Soldering and brazing should be more than adequate for most brewery uses.

Copper is relatively inert to both wort and beer. With regular use, it will build up a stable oxide layer (dull copper color) that will protect it from any further interaction with the wort. Only minimal cleaning to remove surface grime, hop bits and wort protein is necessary. There is no need to clean copper shiny-bright after every use or before contact with your wort. It is better if the copper is allowed to form a dull copper finish with use.

However, you need to be aware that copper can develop a toxic blue-green oxide called verdigris. Verdigris includes several chemical compounds — cupric acetate, copper sulfate, cupric chloride, etc. — and these blue-green compounds should not be allowed to contact your beer or any other food item because they are readily soluble in weakly acidic solutions (like beer), and can lead to copper poisoning (i.e., nausea, vomiting). To clean heavy oxidation (black) and verdigris, use vinegar or oxalic acid-based cleansers like Revereware Copper and Stainless Steel cleanser.

For regular cleaning of copper and brass, unscented dish detergent or sodium percarbonate-based cleaners are preferred. Cleaning and sanitizing copper wort chillers with bleach solutions is not recommended. Oxidizers like bleach and hydrogen peroxide quickly cause copper and brass to blacken; these oxides do not protect the surface from further corrosion, and are quickly dissolved by the acidic wort. Copper and other trace metals are beneficial nutrients for yeast, but the amounts that are dissolved from non-passive oxides can be detrimental to the batch.

Copper counterflow wort chillers should not be stored full of sanitizer or water. Any biological deposits can lead to corrosion in both water or sanitizer. Copper should be rinsed thoroughly with clean water and allowed to drain
before storage.

I seem to recall somewhere that a little copper is goos (from chilling) but once it starts fermenting that you should stay away from copper. The only other information I can find is that it can lead to weird colors and flavors, especially in ciders, etc. Stainless tubing should not be too much more expensive though a little harder to acquire. I may have to use a modification of https://www.homebrewtalk.com/f51/cheap-sanke-keg-fermenter-conversion-kit-completed-447780/ project and make a SS doubled corkscrew for the process.

 

[HopHeavy]

Agreed. A little copper incorporated into wort during brew and chill helps build a mineral base that is beneficial to yeast. I have heard some drop a short length of copper tubing in the boil for this reason. But copper becomes toxic to the yeast in greater concentrations. Cooling fermentation with copper in direct contact with your wort will at least inhibit yeast activity or possibly kill the culture altogether.

 

[Breadontap]

Yeah I looked up the John Palmer article after the reply to the initial post and I agree that copper is probably not the best material. I will try using SS.

Though SS may not be as easily persuaded as copper it should be possible to create a very tight radius which would still make a internal Sanke chilling coil possible.


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[acidrain]

Whether or not you use an inside, or outside coil, you will need to insulate it, right?
I would not use an inside coil because of the possibility of introducing infection. I agree that careful sanitation will avoid this, but I like by brew days simple.
In my mind, an external coil makes more sense than an internal one.
What doesn't make sense is the sheer cost of an external cooler. Why go to all that trouble when you can a free, or at least cheap fridges on craigslist?
I ferment in Sankes too, so I understand the interest, but I ruled out external coolers as an option knowing what I spent on a 1hp chiller for my anodizing line.

 

[Breadontap]

You make a good point about the simplicity of another fridge and the cost of it, but one of the issues I'm struggling with is also space. I don't have much more in the garage.

You are correct in that the keg will be insulated. But keep in mind that you will get no greater efficiency for cooling that you will with a internal coil. A jacket would be second best followed by a freezer or fridge.

The sanitation of the coil is of course increases the risk if infection but if you don't practice good enough sanitation to properly keep a coil sanitized then you probably don't do a good enough job to keep your fermenter sanitized either.

I appreciate everyone's comments and concerns. I'm not trying to be locked into the idea that this is a must. I like most of you are just trying to think outside the box to create something better.

Thanks,


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[acidrain]

What will you use for a chiller?
Drawing heat off is very different from adding heat.
I'm very interested in your methods... I hope this works, Lots of people are in the same boat as you.

 

[Breadontap]

I'm hoping to use a glycol water mix. There are a few examples where people have used window AC units and a ice chest to make a home made version of a glycol chiller.


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[ClaudiusB]

The sanitation of the coil is of course increases the risk if infection but if you don't practice good enough sanitation to properly keep a coil sanitized then you probably don't do a good enough job to keep your fermenter sanitized either.

I have been using internal cooling coisl for many years and would not change anything.

Cheers,
ClaudiusB

 

[acidrain]

I have been using internal cooling coisl for many years and would not change anything.

Cheers,
ClaudiusB

What are you using for a chiller?

 

[ClaudiusB]

What are you using for a chiller?

Built in 2005, has a 30 gallon reservoir, single pump running 24/7 and automatic bypass loop in case all fermenter solenoids are off.
The chiller is used for the fermenters and final wort chilling.
First stage wort chilling is done with city water.
During the summer months only all the hot compressor air is exhausted to the outside.

 

[Breadontap]

That's an awesome rig.


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[acidrain]

That's pretty cool... I applaud your ingenuity!

 

[ClaudiusB]

That's an awesome rig.

That's pretty cool... I applaud your ingenuity!

Thanks guys


Cheers,
ClaudiusB

 

[Stealthcruiser]

Got a picture of this internal coil you are using?

I would just be curious to see how tight of a radius is on it, plus I am not familiar with Sanke style kegs, but I know the opening is pretty small with the spear removed!

And did you coil it, or have it coiled?

Lots of questions, I know, but I used to do a bit of mandrel bending in my job, but never attempted a coil of this small a diameter.