Converting a fridge for fermentation

I bought an STC-100 for $10, and wired it up to a standard home outlet. The top plug is for cooling, and the bottom is for heating. My freezer cord plugs into the cooling plug. I then plug a Fermiwrap heating pad into the heating plug, and tape the pad to the inside of my freezer. Finaly, I tape the temperature probe halfway up the side of the freezer.

It's been a solid setup, and required no modifications to my freezer whatsoever. The temperature probe wire and heating pad cord both fit comfortably under the door gasket without any appreciable loss of efficiency. I didn't have to drill any holes into my freezer or cut the plugs off of any factory cords. I could resell that freezer today just by re-installing the optional shelves and baskets. (But that's not going to happen, not while I have so much beer fermenting.)

You might want to look at the Inkbird Itc-308, because spending $35 saves yourself the trouble of wiring your temp controller to a standard outlet. If you don't already have the tools and wires hanging around, it could actually save you money to buy the more expensive unit.

I converted a chest freezer to a 5 tap "keezer," started with the STC-1000, but it only shows °C, found the same thing (Inkbird ITC-1000) on Amazon that would do °F, was around $15. I already had the other stuff for it (enclosure, etc), but you could pick up the rest of what you need pretty cheap and have a controller that will do both heat and cold for hardly more than $30 if that. So far I've not had any problems, and like the unit. Heck, at $15 even if I burn it up, cheap enough to replace.

I've got mine set to 37°F (3°C) with a 3 minute cycle and a 1 °F variation. I put the sensor in a small glass of water to stabilize temp fluctuations, and so far it's been right on the money. It's pretty easy to set up, the schematics on on the top of the unit, and there's a number of videos and how-tos on the web for putting one together, but if you have any electrical skill it's intuitive to say the least.

Amazon also sells a number of ready-to-go controllers around the $50 range, but they're pretty basic, just didn't seem worth the money when I could make something better and for less.

I use one of these: http://brewerschoice.com.au/shop/brewing-hardware/heaters-and-thermostats/brewing-thermostat-1-socket/

Works fine with a little manual calibration - for example, there's a little bit of looseness in the trim pot that has the temp scale on it (the main dial), so understanding the difference between your dial and actual internal temp is critical.

Really, it depends upon how precise you want to be as to how much you spend.

I don't know if that's "the best one", but we decided to use an STC-1000 for temperature regulation and it's working really great for us.

Especially given the price of the thing it's doing exactly what you want it to do. There are videos on the web on how to use them and if you know a bit about electronic, they're very very easy to setup.