Immersion Lagering Coil

So, it's a little finicky, but I need to keep my brewery footprint to a minimum, which isn't easy when you have 10 cornies and 30 gallons of fermenting capacity. I think this might be a pretty good idea... but will it work?

Use a cheap aquarium pump in a small 1 gallon cooler. Partly fill it with water, and then once or twice a day, stick a frozen bottle of water into the cooler.

Mount a copper coil downwards on a carboy cap. Make a third hole for the airlock.

Pump the water into the copper coil extending down into the wort. Wrap the carboy in a thermal blanket/insulation/neoprene wrap/etc (lots of options for this).

I figure just a couple liters per minute of ~38 degree water running through an Immersion Chiller should be able to at least keep the beer down below 60F. Maybe even colder? Not ideal, I know, but not bad. And the parts are cheap, the system could be stored in something not much larger than a shoebox. Aquarium pumps are like ten bucks. The copper is cheap. I have the rest of the stuff lying around.

Do you think I could keep reasonably lower fermentation temps (and perhaps even do a warm-ish lagering phase) with this set up?

It would be difficult to keep the temps consistent and hit any particular target temps. You might be able to keep it within about 5-10 degrees, but that is far from ideal when you are talking about lagering. Your system would be fine for ale fermentations, but I think you really need to be more precise when you are talking about lagering temps.

Many commercial breweries use your basic concept to control fermentation temps by basically having immersion chillers in their conicals, and there are also plenty of homebrew examples, but you would typically pump temp-controlled glycol through the coils, not water.

Thanks for the feedback. I really don't know how precisely I could manage the temps, but if you've ever left hot water in a carboy and waited for it to cool down... or when you BIAB and shut off the stove and wait an hour, and only lose 1-2*F... it seems to me that the system should be capable of delivering pretty stable temps, just based on the volume... assuming you keep the ice topped off.

For the $20-35 cost of finding out ($20 pump, $15 for copper tubing), and given that we both agree it would be beneficial for ales regardless, it'll probably be worth the investment. Obviously I could do a test batch with water for a few days and see what kinds of temps I'm getting. And the electricity cost should be quite low.

I'll give this thread a few days to percolate, see if anybody else chimes in with corrections, insight, dire warnings, etc...

I do suspect this system might take 6-8 hours or longer just to reach a stable temp in the carboy... but since that's pretty close to a typical lagtime for yeast anyway, it should be a good match.

And actually, I do have a Swiftech MCP655 mag-drive pump (adjustable speed) laying around in my computer hardware odds-n-ends bin. This would actually be a pretty good application for it, eh?

Hook up an ebay aquarium thermal controller to the pump and monitor the vessel temperature. Adjustments will be needed to the amount of ice water needed for duration of cooling. Unfortunately, you might get cold spots in the vessel without any mixing, or stratification.

medusa1066 said:

Hook up an ebay aquarium thermal controller to the pump and monitor the vessel temperature. Adjustments will be needed to the amount of ice water needed for duration of cooling. Unfortunately, you might get cold spots in the vessel without any mixing, or stratification.

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I did consider mounting the pump on the carboy cap, or to the copper coils to get some vibration down into the beer to help circulate it better. I'm not sure how effective it would be, but do you think that would be worthwhile? Obviously, then you'd need to use a non-submersible pump.

I'll probably forego the temp controller on my first test run. I'd probably brew something like an alt-bier and just observe the system throughout the fermentation cycle and see how it came out. Even if it completely failed to work, I'd still have a drinkable brown ale... and I could see what worked, or didn't work, before adding complexity.

On second thought, we don;t worry about cold spots when lagering in a cave or fridge, so don't worry about it.

medusa1066 said:

On second thought, we don;t worry about cold spots when lagering in a cave or fridge, so don't worry about it.

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Well, since you brought it up, and since I have the idea of using the pump's vibrations, and since starters are improved by constant agitation...

Maybe transferring the pump's vibrations into the beer would be a good idea regardless...?

I hope I'm not perpetuating a myth, but I didn't think you wanted copper in contact with your acidic wort after pitching your yeast. I'd lean towards using a stainless coil. It's not as efficient in heat transfer as copper, but it's inert in the wort.

I lager (ferment) in my swamp cooler out in my garage. My swamp cooler is a Igloo Ice Cube. I swap out about a 2 liter of ice every 12 hours, holds 50-52 quite nicely. Is this something you could do instead? Not as awesome I realize, but it works. I have a helles going now and it's hot here.

I thought I read somewhere that you don't want to use copper in applications that have extended contact with beer after brewday. I think that copper will leech into the beer. Its ok for chilling because the yeast use the limited amount that is pulled in during chilling.

You may just want to look into that before you spend any money. Maybe do a proof of concept with copper if you the materials around "lager" some water - if it looks good, use a stainless coil.

mjohnson said:

I thought I read somewhere that you don't want to use copper in applications that have extended contact with beer after brewday. I think that copper will leech into the beer. Its ok for chilling because the yeast use the limited amount that is pulled in during chilling.

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We just had a similar discussion in another thread, but it's applicable here.

passedpawn said:

The brewing illuminati say NO to copper in fermentor, yes in the boil pot.

Apparently, copper sulfate, a poison, can result if copper is present post-fermentation. While I doubt it's a serious problem, I wouldn't tempt the hand of fate.

http://thebrewingnetwork.com/shows/Brew-Strong/Brew-Strong-09-29-08-Metals-that-Affect-Your-Beer

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If you're planning something like this, you might want to consider wrapping the outside of the fermenter with the coils of copper and have the whole thing sitting in a tub of water. That way the cold tubes would be coming in contact with both the fermenter and a waterbath as well.

Awesome. Thanks. Always good to learn. That's why it's good to ask.

As much as I love you guys answering my questions, I also love answering them myself. So I had just starting to read stuff on copper toxicity. Finished beer comes in with a pH around the low 4's. Definitely too acidic.

Ok... so I could still go with my original plan if I changed the copper to stainless steel. Harder to form... BUT I could use a longer run of stainless tubing if I fermented in a corny keg. With the taller/narrower vessel, there'd be less distance from the cooling source to the outermost wort and I could do without the pretty coils if need be. A straight run down to the bottom of a carboy and back up would still offer pretty decent surface area.

I don't like the idea of the copper coils on the outside sitting in a water bath. That seems self defeating. I did consider just using my 5 gallon MLT for a water bath while fermenting in a corny. It doesn't leave a whole lot of space for water though...

How much room do you have for a water bath outside your fermenter corny in your MLT? If you can fit 3-4 500ml frozen water bottles in between, I bet you'd be happy with the results. I'm assuming your MLT is an insulated cooler...

Getting it down to fermentation temps has been a little tougher for me, I usually put at least a 20 lb bag of ice in the water bath around the carboy before I pitch yeast to help get down to temp, then start swapping out frozen water bottles. Put some salt in the frozen water bottles, and don't fill them up to the top (squeeze out the air and then cap to give them room to expand, they don't split this way). It does work, I've made very good lagers fermenting this way. You do need a fridge for lagering at around freezing though.

I have a coleman 5gal cylindrical cooler, so I really don't think I'd be able to get .5L bottles around there, and obviously the lid wouldn't fit on there.

Grainger will sell me 6' of SS tubing for $50. Pricey, but measuring the corny, I realize I could cut it in half and get two pieces, U-shaped, roughly 17" long with a generous bend at the bottom. But then... how to get a decent bend out of it???

Drill three holes in the lid of the corny, 3 rubber grommets, and I'm in business.

But how to bend a U shape in the SS tubing...?

I'm not endorsing them, nor have I bought anything from them, nor am I related in any way, but maybe check out stainlessbrewing.com (or one of the other vendors here). I bet you could describe what you wanted from them easier, and may even be cheaper.

Update this thread if you don't mind, I'm interested in seeing what you come up with.

Why aren't you putting the fermenter in with your serving kegs to lager...I thought that was most people do, right?

I assume you are running a serving fridge since you have cornies...

broadbill said:

Why aren't you putting the fermenter in with your serving kegs to lager...I thought that was most people do, right?

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If you have room to do that... If all you have is a fridge as a kegerator, there's hardly room for a few fermenters AND kegs. Even with my chest freezer that holds 8 kegs, I wish it held 12 so I can't fill it with fermenters.

I'm ripping apart a window AC unit and submerging the coils in a water/glycol solution and pumping that around a fermenter. Just barely started on the actual build, but I'll post pics when it's done.

StoneHands said:

I'm not endorsing them, nor have I bought anything from them, nor am I related in any way, but maybe check out stainlessbrewing.com (or one of the other vendors here). I bet you could describe what you wanted from them easier, and may even be cheaper.

Update this thread if you don't mind, I'm interested in seeing what you come up with.

Click to expand...

Thanks for the suggestion. Stainlessbrewing looks perfect. Prices are cheap and they will make custom bends. I am sure I can get what I want from them. Thank you. An email has been sent to them with 2 rough drawings and an explanation of how I want it to work. I asked if they could make something that will fit, or if I'll need to prototype it in copper first. Most likely, I'll have to prototype it, but there's always the possibility they'll have some metal genius there who says, "Oh yeah. Piece of cake!" Hey, it never hurts to ask.

I have decided to make an insulating blanket from flexible foam/aluminum insulation. Two wraps of that will only add an inch diameter to the corny. That means this thing could sit in any corner of my apartment and not really even be noticed.

Even if I can't lager with it, it would still be a 9" diameter temp-controlled fermenter for like fifty bucks. If you added a real temp controller and a heating pad, you wouldn't be much over a hundred bucks in... and it fits in a broom closet.

I emailed a bit with stainless brewing. It is on. I just need to decide sizes.

Do you think 25' of 1/4" SS sounds reasonable? Or would that be overkill?

Using some spare foam/foil and some acetate sheet (since I don't want it to stick), I have this...



I'll use some tape to make it secure when in use. The rest of the time it can sit flat, inconspicuously against a wall.

Now to get back to the cooling solution. Stainless brewing has me ready to bite on a SS coil that will extend into the corny and provide cold water to manage fermentation temps.

double post

Using some spare foam/foil and some acetate sheet (since I don't want it to stick), I have this...



Now to go back to thinking about the cooling options. Stainless brewing has me ready to bite on a nice long 1/4" steel coil that will extend into the corny.

Using some spare foam/foil and some acetate sheet (since I don't want it to stick), I have this...

View attachment 70781

Now to go back to thinking about the cooling options. Stainless brewing has me ready to bite on a nice long 1/4" steel coil that will extend into the corny.

Sir Humpsalot said:

Using some spare foam/foil and some acetate sheet (since I don't want it to stick), I have this...

View attachment 70780

I'll use some tape to make it secure when in use. The rest of the time it can sit flat, inconspicuously against a wall.

Now to get back to the cooling solution. Stainless brewing has me ready to bite on a SS coil that will extend into the corny and provide cold water to manage fermentation temps.

Click to expand...

Do you brew 5 gallon recipes? You may have to scale back your batch size so that it will fit in the corny that is fitted with a coil (coil will displace some volume, how much I don't know.) Even if 5 gallon fits, I imagine its going to be right at the brim...I would expect some blow off losses.

Again, you will have to see what your volume is in that corny after you install the coil.

I have fermcap to reduce foam. And I can unhook the gas-in port to fit a blow off tube, no problem. but yeah, there won't be much headspace. However this problem should also be somewhat controlled by the fact that I will be fermenting at lower temperatures.

Sir Humpsalot said:

Stainless brewing has me ready to bite on a nice long 1/4" steel coil that will extend into the corny.

Click to expand...

I'm interested to see what they're thinking. What I'm picturing is a sideways coil that will (obviously) fit through the corny lid. Drill a couple of holes in the lid for the coil ends to pass through. Maybe put a short radius bend on the inlet/outlet side to get any connections off to the side and away from over top of the corny lid.

I can see this working, but it's probably more trouble than a dedicated fridge. Perfect if you're spatially challenged though. I was thinking, instead of a small cooler for your ice reservoir, maybe one of those REALLY small fridges that essentially hold a six pack. Put your coolant in there and circulate out through the door. Granted this is probably now getting larger than you want...

Alright. The order has been placed. Let's see what Stainless Brewing comes up with...

also, fyi, I ferment up to the weld line in cornies with fermcap with ales too. Works fine as long as you just clamp a 1/2" hose onto the gas in. I tried keeping the posts on and using a gas disconnect once and it clogged. Was fun how it shot krausen all over when I hit the gas release.

On topic - sounds great. I hope it works for you. Let us know how it goes!

Not exact to your measurements you wanted as far as coil spacing but it should work just fine. Still have some practice to do on the smaller diameters.

By zjosey at 2012-08-14

By zjosey at 2012-08-14
The first small one I did a while back.
https://www.homebrewtalk.com/f41/looking-stainless-coils-325644/index7.html

Awesome. I think this has promise. And it looks great. Can't wait to get my hands on it.

Thanks!

Awesome, I think this will work for you. It'll take up some volume obviously, but it'll chill, especially that length of coil. I'd be concerned about condensation dripping down through the lid along the coil, but there are ways around that.

How about an update on this? How's it working for you?

Offhand, that coil length seems like WAY overkill, and takes up precious volume in that Corny. Just using some very rough estimates, a 25' SS immersion coil will drop 5 gallons of wort from ~200F to 100F in about 20 minutes (lots of variables here, tap water temp and so forth, but bear with me).

So that's ~ 5F/minute. Considering that slows as the temp delta decreases, lets say ~ 1F/minute near the end. I doubt fermentation would add 1F an hour, but lets just say you want to drop 5F an hour for initially getting to lager temps - so compare 60F/hour for 25' SS versus your desired 5F/hour. That's 1/12 so 25/12 ~ 2' of coil, with some pretty generous assumptions, so 2' is probably even overkill.

A single straight section going down and looping back up should be plenty.

You could experiment with some copper and water. The difference in conduction between SS/copper isn't that big a deal - really. It's not the limiting factor that people make it out to be - trust me on this.

Pls let us know how it worked out.

-kenc

At the NHC this year, the Brewhemoth guys kept ten gallons of water at 40 degrees pumping ice water thru their fermenter chilling coil. Very cool!

This was one of our very first small coils. We have advanced drastically over the last 6 months.

Very nice.

Is that for a Corny, or a larger fermentor? Do you have any performance data? It still seems like a lot of coils to me for a Corny. I know my estimate was a wide, wide shot at it, but even a single down-and-back-up loop would be almost 4', probably sufficient, and a few twists could add to it if needed.

Have you thought about making these for bucket fermentors (or maybe I missed those threads, have not been on much lately)? The tubing could just go through a couple extra grommeted holes in a lid, and depending on how they are terminated, could be pulled through to disassemble and clean. I've been meaning to build one like that for years, but I am lazy.

-kenc