DIY Heated Fermentation Chamber

With the Michigan winter creeping in, I knew that I needed to do something to replace my makeshift fermentation setup that involves a bathtub and a space heater. The heater keeps the bathtub warmer than the rest of the house relatively well but it isn't very energy efficient and looks stupid when guests come over. My basement gets pretty cool in the winter and stays within ale temperatures even in the summer so I decided I could get away with only heating and not cooling in this setup.

I figure my costs of this are relatively cheap and should pay for itself over time. Below are my costs and estimate costs once I have my 2 stage temp controller working. I did not include the false bottom costs since I already had the material and it is not absolutely necessary since you could tape the heat cable to the walls of the chamber if you wanted.

-R7.5 (1.5 inch thick) Foam Board 4'x8' = $20
-2 tubes of Liquid Nails (already had on hand)= $0 (around $5 if you have to buy)
-23' of 50 watt ZooMed Reptile Heated Cable = $15 (on clearance)
-2 stage Temperature Controller = $40 (to be built)

My Process:

The foam board I bought was already perforated to be easily divided into two 2' x 8' so I decided to keep all of my dimensions based on a 2' footprint.

I cut all of my foam sections as follows...
Top and Bottom - 24"x24"
Front and Back - 24"x28"
Sides - 24"x31"

I then glued the heck out of this when connecting the sections and used some duct tape to hold sections together until glue was dry enough (about a day)

To give the lid a little better fit when it is in place I added some of the extra foam across the top so that the lid would sit more flush and be a little more efficient.

Once I had the foam box done, I decided to make a false bottom out of some scrap I had and wind the heating cable underneath so that the heat would rise up. I made some swiss cheese like holes so that the heat would have less resistance against the wood.


When inserted into the fermentation chamber, it looks like this and I can actually fit 2 carboys if needed with blow off vessels. After I took this picture I added some weatherstripping to the top to help seal it a bit better when the lid is on...


Here is a picture from the outside, nothing fancy but shows the way my sections are attached to each other...


Performance:

The box heats up relatively fast, about 10 degrees in 10 minutes and holds heat pretty well.

I plan to add some weight to the lid to hold it more tight to the other sections and also cover the top with a thick blanket to hold as much heat as possible.

Either way, this is going to save energy and some bathroom space, hopefully some of you can get something out of this. Let me know if you have any questions!

Is it controlled with a thermostat?

sketerbuck said:

Is it controlled with a thermostat?

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It will be once I get my aquarium temperature controller I ordered on ebay. It should work perfect for keeping beer up to temperature in my cold basement.

Looks like it should work well.

interesting idea, thanks for posting it!

Looks like it should work. I use this stuff which puts the heat directly into the carboy (it gets wrapped around them). Less chance of overshooting due to heating all of the air in the chamber. I can't remember where I got (stole) the idea from, but I'm surprised these aren't used more often. I just got a second one so I can ferment 10 gallon batches in two 6 gallon carboys in my chamber.

11" Flexwatt Heat Tape

kevink said:

Looks like it should work. I use this stuff which puts the heat directly into the carboy (it gets wrapped around them). Less chance of overshooting due to heating all of the air in the chamber. I can't remember where I got (stole) the idea from, but I'm surprised these aren't used more often. I just got a second one so I can ferment 10 gallon batches in two 6 gallon carboys in my chamber.

11" Flexwatt Heat Tape

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That is like Ferm Wrap a lot of people use, it would work but for the cost I wanted to have a chamber I could just place a couple carboy's in and not have to worry about trying to fit a sleeve around.

I imagine that people who use those still wrap the carboy's and buckets in something to keep the heat in?

I thought about a few different options but I just thought it was easier and cheaper to do what I did.

I wanted to update this with the potential energy savings I should get using this new heated fermentation chamber versus my current 'space heater in a bathtub' method.

Over the past week I have been tracking my KWH (electricity usage) with a Kill a watt energy meter.

I used about 15.5 KWH over the past 7 days and my cost per KWH is $0.1212 so for a week it cost me $1.88 just in electricity.

I estimated this to cost me about $8.45 a month ($1.88 x 4.5 (weeks in a month)).

With my new setup I feel that the 50 watt heater will not run nearly as much since it is insulated pretty well. Even if I ran the new heater all day long I would use about half as less energy (about 8.4 KWH per week).

I really think that the new setup will actually only be running maybe 12 hours MAX each day but I will monitor this setup as well once I get my temperature controller in the mail and hooked up. If my walls are insulated well enough, I hope to only run around 6 hours per day.

Using this setup I think I will easily save $6 - $8 per month so this will eventually pay for itself and save some energy in the process. Since this is mainly going to be used in the winter (about 6 months in Michigan), I will recoup my costs in less than 2 years using this each winter. Also, my results have been during days that were not as cold as it will get during the really cold days in January/February.

I will update once I have some real stats using the actual chamber. Hopefully this helps some of you who are debating on making something similar.

curious at the total cost including electrical usage compared to the 40 watt incandescent light I use with my buckets. (and no, I have never experienced light struck on my extremely hoppy brews)

OneHoppyGuy said:

curious at the total cost including electrical usage compared to the 40 watt incandescent light I use with my buckets. (and no, I have never experienced light struck on my extremely hoppy brews)

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I am sure it would be similar to my 50 watt setup with the heat rope but I have mine spread out under the false bottom so it might be a little different because the heat is coming from a smaller source and would need more time to run to get the chamber up to temperature.

That is just a guess but I doubt it would be much different. I am not sure if you have tested yours out but my chamber generally heats up 10 degrees in 10 minutes if that helps. I could try a bulb in mine to see if it heats up as fast.

OneHoppyGuy said:

curious at the total cost including electrical usage compared to the 40 watt incandescent light I use with my buckets. (and no, I have never experienced light struck on my extremely hoppy brews)

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That's because standard incandescent bulbs emit virtually no energy in the UV spectrum. In that respect, they're totally safe as ferm chamber heaters...

Cheers!

I was having the same problem - winter came and now the garage is ~50deg.
I took an old hair dryer (had a bad cord) and set it on low. Then I hooked it up
to the thermostat through an SSR. I pointed the hair dryer at the corny keg where
the temp probe was taped on.

When I started it, it was at 57 and I wanted it to be 65. It ran for about 1.5 mins and raised
the temp from 57 to 110. The thermostat temp ran up to 70. But then dropped back down to 58. I left it overnight and it eventually stabilized at 65. Now the hair dryer runs for less than 30 sec. for a while (haven't stayed in there long enough to determine how many times it ran in an hour. In 24 hours, it consumed .18KWH (kill-a-watt meter.)

Of course, the chamber is set to the size of 2 corny kegs (adjustable 2 chamber fementation chamber using mini refrig.)

Adam

adam01 said:

I was having the same problem - winter came and now the garage is ~50deg.
I took an old hair dryer (had a bad cord) and set it on low. Then I hooked it up
to the thermostat through an SSR. I pointed the hair dryer at the corny keg where
the temp probe was taped on.

When I started it, it was at 57 and I wanted it to be 65. It ran for about 1.5 mins and raised
the temp from 57 to 110. The thermostat temp ran up to 70. But then dropped back down to 58. I left it overnight and it eventually stabilized at 65. Now the hair dryer runs for less than 30 sec. for a while (haven't stayed in there long enough to determine how many times it ran in an hour. In 24 hours, it consumed .18KWH (kill-a-watt meter.)

Of course, the chamber is set to the size of 2 corny kegs (adjustable 2 chamber fementation chamber using mini refrig.)

Adam

Click to expand...

I know hair dryers pull a ton of energy when running but if it only runs for 30 seconds to get the temperature up then that might be a good option.

I am curious of your setup as it sounds a lot like mine but how do you setup the blower?

I setup the blower (hair dryer) on a SSR connected to the thermostat 'heat' line.
The hair dryer is on low and it pulls about 360W.

SSR's if you don't know are a solid state relay. You use one to control switching on and off 120v power. So you wire the relay in series with the power to the load (hair dryer.) I
put the SSR connected to the power line. The neutral is always connected to the dryer.
When the thermostat calls for heat. It energizes the heat signal. This is hooked (along with the common signal) to the SSR on low voltage side to close the relay, thereby supplying power to the dryer.

The dryer just sits in the fermentation chamber and is pointed (resting against) the keg.

UPDATE:

I have been using the fermentation chamber with the ebay aquarium temperature controller for just about a week and have had excellent results.

I have not even used 2 KWH in the past week keeping my fermentation chamber at 70* F (58* - 59* ambient temperature in basement), this is about what I figured it would use based on my estimate. That means it has cost me $ 0.23 to run this for a week.

If I extrapolate my results, I should save around $7.50 a month in energy costs compared to my previous setup. I also think that I should use the most energy/money when it is coldest outside so I figure my savings will go up marginally in January and February.

I am really happy with this and highly recommend this since it pays for itself and lets you make better beer by keeping it at a consistent temperature. Let me know if you have any questions!

Thanks for posting this. I have been using a space heater in a bathroom and would love to keep everything in the spare bedroom. I can't wait to give it a try. I'm even wondering about building a shelf above the fermenters for conditioning the bottled brew.

Nice build. How warm does the heat cable get? For instance, could you hold it in your hand comfortably? What is the length of just the heated part of the cable? Should I avoid having the heat cable directly underneath my plastic fermenter (I'll use a false bottom like yours)?

jmf143 said:

Nice build. How warm does the heat cable get? For instance, could you hold it in your hand comfortably? What is the length of just the heated part of the cable? Should I avoid having the heat cable directly underneath my plastic fermenter (I'll use a false bottom like yours)?

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I am not sure how warm the heat cable gets but it doesn't get hot enough to where you cannot hold it in your hand. I would guess it goes up to 100 - 110 F which is more than enough for this chamber.

The length of the cable I bought is 25', I think 6 of that is not heated and would be the part that stuck out of the actual chamber itself.

I would avoid having it too close to the actual fermenter unless you have really good temperature controls. I use my false bottome setup and even put a blanket down for added buffering of heat and that works great.

Let me know if you have any other questions, I am really loving this setup and highly recommend.

hi there.

I have built an incubator similar to the ones discussed here and have tested it extensively toward brewing a Saison tomorrow. I hope to use it to get the fermentation up around 90, but have a question:

how do y'all deal with blow-off in primary fermentation. can I just cut a hole in the side, run the blow-off tube through it into a bucket of water, and seal around the tube? would I lose a lot of heat? the tube would then require cleaning as well...

and how about when the fermentation slows and doesn't need a tube? where does the gas go? or does THAT just "seep" out?

thanks!

I use a several quart pitcher inside my chamber for the blow off. No need to put a hole in your wall if you have the room inside.

and how about when the fermentation slows and doesn't need a tube? where does the gas go? or does THAT just "seep" out?

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I'm not sure what you're asking here, but you can leave the blowoff on for the whole fermentation if you want to. In my case, I usually leave the blowoff on until I take my first gravity reading. At that point, high krausen is over, so the blowoff is no longer needed. I then replace the blowoff with a 3 piece airlock.

kevink said:

I use a several quart pitcher inside my chamber for the blow off. No need to put a hole in your wall if you have the room inside.

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well, I feel like a moron for not thinking of that on my own. there IS room... it's 24x21 in there. thanks!

kevink said:

I'm not sure what you're asking here, but you can leave the blowoff on for the whole fermentation if you want to. In my case, I usually leave the blowoff on until I take my first gravity reading. At that point, high krausen is over, so the blowoff is no longer needed. I then replace the blowoff with a 3 piece airlock.

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I suppose I could do that. one of the things I've been fretting over is that I actually had been using, until now, a webcam trained on the airlock to detect motion and report bubbles. while the enclosed system will reduce false positives, there's no light in there. unless I put an LED in...?

thanks for the quick reply - I'm new here and appreciate it.

No problem, neighbor! I live near KOP.

A webcam for your airlock?! I just open my chamber up a few times to take a look. No biggie.

kevink said:

No problem, neighbor! I live near KOP.

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ha! of all the potential places on Earth, you're 20 miles away.

kevink said:

A webcam for your airlock?! I just open my chamber up a few times to take a look. No biggie.

Click to expand...

you're right in that it's no big deal, but then how do you know the difference between 1 bubble every 4 minutes and 1 every 40? or that it's producing CO2 at all, unless you're watching long enough to catch one? I also struggle with knowing when it's done... although the handy refractometer I just got my help with that.

incidentally, the Saison started fermenting overnight last night and will go into the incubator late tomorrow night. got a lager going in the 50-55 degree area of the basement and it smells GOOD.

you brewing anything?

calvin76 said:

ha! of all the potential places on Earth, you're 20 miles away.



you're right in that it's no big deal, but then how do you know the difference between 1 bubble every 4 minutes and 1 every 40? or that it's producing CO2 at all, unless you're watching long enough to catch one? I also struggle with knowing when it's done... although the handy refractometer I just got my help with that.

incidentally, the Saison started fermenting overnight last night and will go into the incubator late tomorrow night. got a lager going in the 50-55 degree area of the basement and it smells GOOD.

you brewing anything?

Click to expand...

The #1 rule in homebrewing is to not trust the 'bubble count', trust the hydrometer/refractomer to know when fermentation has stopped. There are countless posts about this out there if you need more information.

barhoc11 said:

The #1 rule in homebrewing is to not trust the 'bubble count', trust the hydrometer/refractomer to know when fermentation has stopped. There are countless posts about this out there if you need more information.

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yeah, hence the refractometer. I'm always terrified of contamination due to the larger sample needed for the hydrometer. one side benefit is that the cam does let me know when the fermentation kicks off, or if it explodes, or makes a mess, etc.

calvin76 said:

yeah, hence the refractometer. I'm always terrified of contamination due to the larger sample needed for the hydrometer. one side benefit is that the cam does let me know when the fermentation kicks off, or if it explodes, or makes a mess, etc.

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The webcam idea is cool but i assume you would need to turn a light on inside the chamber? I would say the purpose of this is a low cost/energy solution to keeping proper fermentation temperatures, keeping a light bulb going in this all the time so that the webcam can capture the bubbles kind of defeats that purpose.

I think you are better off just opening the chamber once a day and checking to see if there is any activity, if there is still some bubbling, you can assume that there is still fermentation going on but after 1 week you should be done either way.

calvin76 said:

I'm always terrified of contamination due to the larger sample needed for the hydrometer.

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You do NOT put the sample back in the fermenter, so either method has the same potential for contaminating your beer. Just sanitize what you're getting the sample with and you have nothing to worry about. As for the camera, I think once you do a few batches, you'll find out that it is not needed. If you have a blow off there will be no explosions, nothing to clean up, nothing you really need to see. Check it out when you come home from work, before bed, and in the morning.

And I agree with barhoc. Do not gauge fermentation by the airlock.

kevink said:

You do NOT put the sample back in the fermenter, so either method has the same potential for contaminating your beer. Just sanitize what you're getting the sample with and you have nothing to worry about. As for the camera, I think once you do a few batches, you'll find out that it is not needed. If you have a blow off there will be no explosions, nothing to clean up, nothing you really need to see. Check it out when you come home from work, before bed, and in the morning.

And I agree with barhoc. Do not gauge fermentation by the airlock.

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I used the get the sample with a (sanitized) measuring cup, and dispose of it. hated tossing out 2-3 beers in the process, too. now, with the refractometer, I just use the eyedropper-type device.

thanks to everyone for your advice.

I'm glad to hear you are having excellent results with the reptile cable. That is what I put in my chamber. I haven't fermented in it yet, but I've done some testing and I get a pretty quick warm up as well.