June 25, 2013

My fermentation chamber

Today's post is about my fermentation chamber (obviously) and how I got it set up on the cheap. There's a little bragging and some instructions about how to set up your own. If I had more room in my house I would have something along the lines of my current set up plus a separate modified freezer that I could use for kegging and lagering but space is tight in the current home and I'm already taking up a lot of space with all my other brewing gear, fermenting beer and bottled beer. However, I'm happy with my current set up and it works for 99% of everything I need.

I started out brewing without good fermentation control. My first few batches began life with no fermentation temperature control and then I moved on to the water tub/swamp cooler method. That sort of worked for keeping the beer cool in the house during cold months but I could never keep the temperature in the 60s for most of the year, let alone a stable temperature. So my beers were less consistent and often less than ideal. Last year I took the plunge and decided to upgrade my brewing set up with some temperature control.

My set up is really simple. I found a small used fridge for sale on craigslist. Actually it was a fridge somebody was using as a kegerator so it has a hole in the top of the fridge where the tap tower was. The prior owner unloaded this fridge for just $40 and included a 2.5 gallon CO2 tank and regulator. So all in all that was a good deal, especially since I can convert it back into a kegerator in the future if I need to. This fridge is probably from the 70s or early 80s judging by the ugly color. It's a little larger than other small fridges on the market these days which makes it large enough to barely fit two pin lock corny kegs (although I haven't tried hooking up anything to the posts) and it is just slightly too short to fit a 7.9 gallon bucket with an airlock. I need to modify an airlock to fit it but I've been squeezing airlocks in for the time being.

As I said, it was an ugly color. It showed up a poopy brown color with a turquoise interior. I bought some black chalkboard contact paper on Amazon and covered the exterior, transforming it into a nicer black fridge. Then the beer stickers are making their way to the outside.

The outside

And the inside...with fermenting beer
The fridge has an analog temperature control but like most fridges it is not designed to go up to the 60s so it needs a separate temperature control because I certainly have no business trying to rewire it. This task was easy. I picked up a Johnson Controls digital temperature controller on Amazon for around $60. This device is awesome. I can plug in the controller, set a temperature and then plug the fridge into the controller. The controller has a temperature probe I can tape to the fermentor and the controller will turn on the fridge when the temperature drifts out a certain number of degrees from the target temperature. I had to play with the desired temperature and the number of degrees I would let it drift before turning the fridge back on to try to keep it in a desired range of 2-3 degrees. Now I have the settings dialed in so I can keep it at the same temperature for most of the fermentation and occasionally it will drift down a degree. A side benefit of the Johnson controller is that it can be set to keep a warm temperature by turning on a heat element when the temperature drops below a set temperature. I just bought a couple heat elements that I plan to use to ferment saisons very warm so I'll see how those do in coming weeks.

I only run the temperature control for the first few days for most beers because after that the yeast are less inclined to spit out off flavors as fermentation starts winding down. As the temperature gets into the 70s at ambient the yeast will work a little faster and off flavors will get cleaned up quicker. Bigger beers need more time so I might control the fridge temperatures for as much as a week.

The problem with this set up is that I can't reach lagering temperatures. The fridge's internal temperature controls won't let it get down below 38-40F which is a touch too warm. Even setting the Johnson controller at 32F, the internal controller will shut off the condenser. I can somewhat cold crash at those temperatures and imperfectly lager beer but it isn't quite the same. When I brewed a gallon of doppelbock a couple months ago I just used my kitchen fridge set at 46F for fermentation and lagering because it didn't make sense to run a second fridge for several weeks at 40F for a single gallon that also fit in the kitchen fridge. I tried the doppelbock over the weekend and while it misses a little of the lager cleanness it is still very smooth and delicious.


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