« on: February 07, 2012, 06:45:31 AM »
I use a small heat wrap like those available at Northern Brewer or B3 or Rebel Brewer and wrap the fermenter with reflective insulation (like that you use for a water heater) with a thermo well and digital temp controller. Works well, even down to 38 degrees and uses very little energy.
I've definitely looked into and am interested in this technique but issue is you can only do this with one fermenter unless you have more than one thermo well and dig temp controller. I'm usually doing 10 gal batches in two fermenters minimum, so that'd be at least two of everything. Plus sometimes i'm fermenting and carbonating and want higher temp.
I do two better bottles with the same batch and one thermowell immersed in only one fermenter. I figure they will both be the same internal temp, and according to the fermometer they are the same. Def a low teck approach that works and is cheap. I'll take a picture today and show you. I have a batch of single hop beer fermenting on my brewery floor right now wrapped in nothing but a piece of insulation with a Titans sweat shirt draped over the top and it has stayed at 66 degrees even at below 40 ambient temps.