My plans include getting a seven-cubic-foot freezer, which is the ideal size for this purpose. It will allow me enough space to have two kegs on tap and one batch fermenting. I will not be fermenting in the traditional plastic bucket, however. Instead, I will use a corny keg with a special lid fitted with a blow-off tube. CornyKeg.com has a good description of how to turn a corny keg into a fermenter if you want to do it on your own. The reason I am using a keg for this is mostly because I want all three kegs to fit in the freezer at once. Also, if I used my normal equipment, it would necessitate lifting a glass secondary fermenter into and out of the freezer – something I am not too keen on due to the possibility of dropping it. In addition, I am leery about getting my glass too hot or too cold for fear of it breaking. Glass carboys are sturdy devices, but in the event one does break, it can be quite a mess to deal with.
The trick to getting really good temperature control of your brewing beer, I am told, is to tape the probe of the temperature controller to the fermentation vessel. Cooling the box itself may seem adequate, but fermentation is an exothermic process, meaning it releases heat. Thus, the fermentation keg could easily become warmer than the rest of the freezer, even if only by a few degrees. The kegs I use are insulated, in that they have a jacket of air between the outer and inner bulkheads, but taping the probe to the keg is still the best chance I have to cool the beer sufficiently for optimal fermentation. I will report on the process as it goes forward, and post the recipe I end up using.
Do you have any tips for making a great lager at home?