One of the many things I love about brewing is that I get to incorporate not only my love of beer, but my love of building things. Making crazy gadgets to suit the task at hand is something I have a lot of fun doing. Thanks to the many great articles written and shared by other home brewers, some gadgets have been tried & tested, with the rest of us benefiting from those who have gone before. This is one such gadget.
As I move deeper into brewing territory, other variables in the beer making process start to come into focus and the time comes to tinker with them to see if we can continue to improve our beer. Fermentation temperature is something that I hear many people talk about. Jamil Zainasheff has gone so far as saying it’s a “game-changer”. Wow, to say that, intrigues me. Up until now, the area of my basement that I use to ferment has a fairly steady temperature of about 68-70F, which is perfect for most ales. At one point last summer, I was fermenting a blonde ale when the compressor on our AC unit crapped out. It ended up fermenting in the 74-75F range, which is fairly high. The beer actually turned out fantastic, but I don’t know how much of a role the higher temperature played in that. Lagers, on the other hand, are different story. You need to have control over your temperatures. Since we’re now brewing 10 Gallon batches, it gives us the opportunity to split the batches into 2 five gallon carboys and try different yeasts, different fermentation temperatures and different dry hopping rates.
One way to gain control over our fermentation temperatures is to build a dedicated fermentation chamber. I lucked out a few weeks back and scored a medium sized chest freezer that someone down the street was tossing out. I suppose you could use a refrigerator, but this is what I have. A chest freezer will also hold more carboys and/or kegs. (I’m also not certain whether or not a fridge will allow you to get down to the temperatures needed to properly lager (32F-35F), but I could be mistaken.)
So you’ve got your fridge or freezer, now what? We need to override the internal thermostat and give ourselves the ability to dial in the temperatures we want. There are a few ready-to-go temperature controllers available from Johnson Controls and Ranco that seem to do the job well. They will cost you a little bit more up front, and will also cut out any of the fun building your own, but who wants that? Well, maybe some of you, and that’s totally cool. For me, I like to build stuff, so that’s what I’m going to do.
To get started, we need to source out the following materials:
UPDATE: Please see my update on how to add a relay into the circuit to make your controller safer and extend it’s life…
- Utility Junction Box – $19.89 (Home Depot)
- Husky 9ft/14 gauge tool replacement cord – $11.59 (Home Depot)
- GFCI duplex receptacle + faceplate (Home Depot)
- 2′ of 14 gauge romex wire (Home Depot)
- 1 x 1/2″ loomex cable connector (Home Depot)
- 2 Marrettes for joining wires (Home Depot)
- temperature control unit – $26.99 (eBay)
** NOTE – the temperature control unit is a great deal, but be aware that it does come from China, so it is going to take some time to get here. Order ahead, and be patient, mine took about 2 months to arrive.
The tools you’ll need to complete this job are:
- flat head screwdriver
- phillips screwdriver
- wire stripper / cutters
First thing we’re going to need to do is define where we’re going to cut our openings in the front panel of the junction box. What I did was measure out the size of the temperature controller and the size of the faceplate (not the receptacle) and spaced it out evenly and centered on the panel. Then I drew up a template on paper and stuck it on the inside of the panel. (You could probably lay the parts on the front and use a sharp scribe to scratch the perimeter lines on the faceplate as well, (** use the receptacle for this part of it) Drill holes in the corners of the windows, as well as hole for the screws that attach the faceplate and receptacle. Then use a jigsaw to cutout the windows like this:
This is what it looked like from the other side when finished:
You can then insert the temperature controller by removing the two orange side clips, and then reattaching them once it is in place. Also at this time, you can see how your receptacle fits, and make any adjustments. (in case the opening is too small)
Next, you need to drill a 7/8″ hole into one of the sides of the utility box and insert the cable connector like this:
Now on to the wiring. This is the schematic we need to follow:From the romex, cut 3 pieces of approximately 6 inches each, and remove the outer insulation. You’ll need 3 pieces of the ‘white’ wire, and 2 pieces of the black wire. Use your wire strippers to remove about 3/8″ -1/2″ of insulation on each end.
Next, take 2 of the white wires and connect one of them to the #2 outlet (see diagram above) on the temperature controller unit. Connect the other to one of the ‘silver’ screws on the duplex receptacle.
Take the 2 black wires and attach one to the #1 outlet on the temperature controller, and the other to the gold screw on the duplex receptacle.
Take the last black wire and attach it to the #7 outlet on the temperature controller.
Take the black wire from the receptacle, and attach the other end to the #8 outlet. You can also attach the temperature probe to the #3 & #4 outlets.
Then, feed the the replacement power cord through the utility box hole with the cable connector. First connect the green grounding cable to the green screw on the receptacle. Connect all the white wires together with a marrette, then connect the black wire from the power cord to the free end of the black wire from the #1 spot on the temperature controller with another marrette like this:
Tuck the wires back into the box and put the faceplate back on. Screw it into the main box and don’t forget to tighten the cable connector where the wires come in so they don’t pull out unexpectedly.
And there you have it!
All you need to do is set your fridge/freezer to it’s coldest setting, plug it into the receptacle on your new temperature controller box, then plug the temperature controller box into a wall outlet. Place the sensor probe inside the fridge or freezer. I taped mine to the side of a glass jar filled with water, that way the temperature won’t vary as much as the air, and will give you a more accurate reading. Set your parameters and desired temperature setting using the instructions that came with the temperature controller. My unit only displays in Celsius, so I drew up a handy chart to convert to Fahrenheit: Celcius to Fahrenheit Chart