Fermentation Chamber Build - Mini Fridge

I've read and marveled at so many fermentation chamber builds I thought I'd share my own. I've been planning this for a while and finally got around to starting. I've put 2 evenings time into this project so far and am very happy with my progress. The thought behind this chamber is to simply keep a consistent temperature for me to ferment ales, wine and ciders. My basement is not completely underground, so I get temperature swings of 10-15 degrees and in the winter I can get temperatures as low as 40 fahrenheit.

What you see below is the framing of the chamber w/ the side, back and bottom walls on. I plan on having the top of the chamber removable so I can go in from the top. Also you can see the larger gap between the framing on the front... this is for a door that will be hinged on the bottom. The fridge will sit on the platform on the top right. The thought here is to have fans to blow the cool air from the top and let the cold air drop.


Front view.


With the fridge inserted.


Front view with fridge.


I have some time tomorrow night which will probably be finishing up cutting out the plywood for the top and the door. If I have time I'll get to cutting the insulation (1.5" insulation board). I'm heading out of town on Friday so I won't get around to working on it until next week.

Moving forward, I have a temp controller on it's way which I'll wire in to run the fridge / fans when cooling is needed and some sort of heating element when heat is needed (this will be phase 2 for winter time). I'm thinking of the reptile lamps that some have used for heating.

I'd love to hear everyone's thoughts as I continue on with this project.

Thanks again to the homebrewtalk community... it's truly a great resource!

 

Nice start. Do you think you could reach lager temperatures? Also how many fermenters will it hold? Cheers.

 

I've never understood these builds. Over working a mini fridge when so many other options work better. It looks clean though.

 

chessking, I'm not looking to reach lagering temps and further, don't think the small 1.8cf fridge I'm using would be able to get the temp that low. I'm looking to hold 2 fermenters with some room for blow-off/etc.

phoenixs4r, not sure I'll be overworking the fridge since this will be in my basement where temps don't regularly get over 70 fahrenheit. I'm more looking for consistent fermenting temps. Winter will be interesting, but we'll deal with that when we get there. What are the "other options" that work better?

 

Phoenix, I don't understand why people don't understand these builds. You're not asking a mini fridge to keep a larger space at regular fridge temps (upper 30"s F). You're asking it to keep a larger space at a higher temp, generally in the 60's F. That's not a big stretch by any means. No, they aren't designed to cool the larger space, but considering you're placing less demand on them in terms of temperature needed, it probably evens out pretty well. If the fermenter is kept in a conditioned basement or other part of the house, you're generally only looking at a 10-15 degree difference in temps, which is not asking much of a mini-fridge.

Considering how many of these builds there are, it obviously must be somewhat worthwhile.

And yes, there are other options, but are there any as cheap and easy as this? Counting the fridge (AND having to buy a second one), the temp controller, and everything else, I will have spent about $150 on my ferm chamber build, and it will hold 4 fermenters (buckets or 6 gal better bottles). That's not bad.

 

I think the one time effort and cost of the build will pay off with better beer, if temperatures can be precisely controlled. What about those guys who freeze 2 liter bottles and constantly change them out over the span of fermentation. Sure, cheap and simple, but the hassle of the workload, and responsibility are tremendous. But I bet their beer is fantastic. Its worth it to them.

 

Got my STC-1000 in the mail today and quickly drafted up my wiring. My thought here is that I will have a 2 gang box that sits on the outside of the chamber and a 1 gang box that sits on the inside of the chamber. The 2 gang will hold the temp controller and an outlet (1 always on and 1 for cold -> fridge). The 1 gang will hold an outlet (1 for hot -> future heat source, and 1 for cold -> fans to circulate air).

 

Couldn't you keep all the outlets on the outside of the chamber and just run the heat/fan cords through the bulkhead? Just a thought. I suppose if you are only trying for 60 degrees or so it probably doesn't matter. I'm just thinking about moisture and electricity and I get nervous. Of course if you have already wired it, then disregard.

 

That is a good point... and one that I did not really think about because I have seen other builds with outlets inside the chamber. Can anyone comment on outlets they have wired inside the chamber and how it has been?

 

I've finished up the chamber over the past few weeks. Took some pictures along the way but haven't had time to get them posted until now. I didn't hear much in terms of others and outlets inside of the chamber, so I decided to move forward as planned. I'll continue to monitor once I start to make use of the chamber (I have an edwort apfelwein started, but not in the chamber because the wife wants to stain the chamber). Needless to say, here are some pics of progress. I'll get the finished product pictures posted soon as well.

Temp Controller wired and tested:


Close-up:


Outside paneling attached and fridge mounted:


Shot of the inside through the door:


Inside outlet and fans for circulating cool air:


To come are pictures of the inside insulation caulked and taped, outlet face plate and taped, door insulation, and door latch.

 

Very nice work! Looks really clean. What did you insulate with?

 

Disregard. Just saw it. Lol

 

Nice progress. If it works the way you want it to , you will probably be using it for years to come. I think you will appreciate a proper finish on the outside, as time goes by and it becomes an indispensable piece of your equipment. Good call by SWMBO. Looking forward to seeing some beer in there.

 

If you didn't, you could use the Weather Resistant (WR) outlets available at any hardware store. That will help to protect them from any moisture present in the chamber. You'll also want to keep a small bucket of Damp Rid or baking soda in there to help keep the humidity down as well.

Looks good! I like how you mounted the mini-fridge. I'm in the process of tearing a larger dorm fridge apart, and I'll be using the guts in a similar build. I've run into a snag building the doors (the doors are 4" taller than my clamps are long ), or it would probably be running by the end of the week.

Can't wait to see some pics once its stained. Is this going in the house somewhere, or does the wife just want it stained regardless of where it is going to be located?

 

One item I am still trying figure out is what to use on the floor of the chamber to distribute the weight of the carboys... I was thinking, worst case, to use 2 1x3's as rails.

What does the greater community suggest?

 

Yea, the wife just bought the stain last night... going with a dark mahogany.

Probably the 1st fermentation I'll use this for is my 2 batches of wine in Oct/Nov. Will probably need my heating unit setup by then.

 

Thanks, I'll have to look into the WR outlets. Also thanks for the note on Damp Rid / Baking Soda.

This unit is going to reside in either the garage or basement, but the wife still wants it to look "nice". We are going with a mahogany stain to match other shelving in our basement. Personally, I wanted to just slap stickers all over it

 

On the minifridge that I built out for fermenting, I lined the inside with Formica laminate that is used on countertops. I applied it directly over the foam insulation, including the floor. It is light in weight, but very rigid.

 

I am considering using self stick vinyl tiles. I had some left over from a project at work, so they cost me nothing. They will protect the floor from the carboys, as well as making it "mostly" waterproof. If those don't hold up well, I will either put in a solid piece of vinyl, or do laminate countertop, like the previous poster recommended.

 

I had seen other posters use laminate counter top but the only sizes I can find are 4'x8' sheets. The tiles are a good idea... I think I have some laying around as well.

 

Hey just wanted to ask how satisfied you are with this style of chamber? I have two of this size fridge that were given to me an and i want to do the same thing. Looks nice.

 

Wouldn't mind seeing some pictures of the finished project.

 

Here are some photos of the chamber at its current state (almost finished - still need to stain it).

Here is the chamber from the exterior. It did fit through the door to get it into my basement.


Front door open. I snapped these photos while racking some items in the chamber, hence the 2 1gal jugs of mead. What you don't see here are 2 5gal batches of wine. I wanted this chamber to fit at least 2 5gal carboys; I over estimated and it fits those and some.


The internals; fans for cooling and personal heater for heating wired up to the outlet inside of the chamber.


Full chamber through the lid.


A few of you have asked how I like the chamber / design. I'm happy with it but I have noticed 2 flaws.

1. Everyone talks about this one; you need to attach the temp probe for the temp controller to the carboys to prevent continuous cycling of heat/cool. I'm still deciding what to use here.

2. With my lid being removable, I lose heat quickly (I believe) through the non-sealed edges. I'm thinking about sealing the top to prevent this. The door on it suffices my needs.

 

I'm currently just using blue painters tape to hold my temp probe against the side of whichever carboy is undergoing active fermentation at the time. I'm planning to take a small piece of leftover foam from insulating mine, digging out a recess for the probe on one side, and then taping that against the side of the carboy to insulate from the ambient temps in the chamber.

 

By the way, looks good!

 

Honestly never thought of that... I have plenty of styrofoam / insulation around!

 

What am I looking at cost wise to build one of these?? If you have already answered that question my apologies, I honestly just clicked through to view the final pics as well as your final thoughts on the build. I am a new home brewer and as I have done more research on it I have come to realize how critical it is to be able to maintain certain temperatures. Also, I would like to try to lager sometime in the future and will need something to do it with. Is it more cost effective to build one such as yours, or convert a mini fridge or even a full size fridge with a digital thermometer?

 

This really depends on what is available to you where you live. Looking back on it, it probably would have been slightly cheaper for me to buy a full-size fridge or chest freezer and a temperature controller.

If you want to ferment AND lager in the same piece of equipment, your best bet is probably a side-by-side refrigerator. You can lager in the freezer section and ferment in the fridge section using 2 different temperature controllers. There are plenty of builds showing that here on HBT.

For me, I already had a mini-fridge on hand, although it wouldn't fit a 6 gallon fermenter inside. So I decided to build a cabinet for it, since I'm pretty handy with woodworking. My cabinet can hold 5x 6gallon + fermenters (buckets or better bottles), and possibly 1-2x 3 gallon better bottles or gallon jugs as well.

Really, I guess it boils down to if you want to build something yourself, or just buy something already built and just add your own temp controller. I enjoyed building mine, and now its a furniture quality piece that can sit in our living room.

 

I just realized I never stated how much I spent. Mine is a little over-budget, mainly because I ended up having to buy two more used mini-fridges to finish my build (my first one that I'd had since college sprung a refrigerant leak, the second one didn't have the kind of coils I wanted, the third one did).

If you take out the $100 I spent on the two mini-fridges, my build cost me about $175-200. I used 2x4's to build a frame, then skinned it with 1/8" plywood, and then insulated with 1" and 1/2" thick pieces of blue foam board. I stained the plywood, added a 3/4" maple plywood top, and then built my own cabinet doors for the front. I also added 4 casters so I can roll it around.

Lastly, I have 4 electrical outlets controlled by the temperature controller (2 heating and 2 cooling), and another 2 that are always on. The electrical ended up costing me about $80-100 of the total cost, although I ended up with a lot of spare parts that I'll use for other projects as well.

 

Bearded Idiot and Skottree,
I use 3-gal Better Bottles to ferment, so I think I could use less room in a chamber. I have a question about the fridge. I would like to have my chamber be slightly more aesthetically pleasing, more like furniture. I would rather not have the fridge hanging off the side. I understand that the back of the fridge needs to be outside the box, but do the sides? Do you know if there is any problem covering the sides and top of the fridge with wood and leaving the back open to vent?
Thanks

 

eanmcnulty,
It depends on what kind of mini-fridge you use. If you buy the one with external coils mounted on the back, then it shouldn't be an issue if you enclose the sides of the fridge. If there are no visible coils on the back (or sides) of the mini-fridge, then the coils are spread throughout the walls of the fridge, and you shouldn't enclose it completely with wood.

The difference is the external coils are used to disperse the heat collected by the unit. In these units, all the heat is collected is dispersed from these external coils.

In the other units, the coils are contained inside the walls of the fridge, and the walls themselves are used to disperse the heat. If you cover these walls with wood, then it will limit the ability of the fridge to disperse heat, and you will end up over-working the unit, and potentially cause it to malfunction.

For what its worth, the chamber I made is furniture-quality, and my wife keeps asking me why I have it hidden in the laundry room, rather than keeping it out in the living room where we can see it. I completely removed the cooling components from the mini-fridge and mounted them onto the frame of my cabinet. Only the compressor and external coils show, and I could probably hide them behind more stained wood panels if I wanted to.

 

eanmculty, from the reading I've done you only need be concerned with not covering the areas of the fridge which are used for heat dispersion. Some fridges actually disperse heat through the top and side panels.

Hoping others can add more.