Beer brewer’s temperature controller
posted Sep 13th 2009 9:00am by Mike Szczysfiled under: beer hacks, home hacks, misc hacks
Steady fermentation temperatures, usually at about 65 degrees Fahrenheit, are an important part of brewing beer. Because of this, the wort (unfermented beer) is often temperature controlled during fermentation. [android] needed a temperature controller for fermenting beer in a chest freezer. Much like the energy efficient fridge hack from last month, the chest freezer is switched on and off to achieve the desired temperature. Instead of buying a controller, [android] built around an existing design. His project uses a solid state relay to switch an outlet on and off.
The temperature is controlled by a home thermostat. He removed the thermistor from the unit and extended it with 24 gauge wire so that it can go inside of the chest freezer. Utilizing a junction box, the freezer is plugged into one switched outlet and controlled by the thermostat via the relay. The other outlet is unswitched and provides DC power for the relay using a wall wort transformer. Although this thermostat cannot be set cold enough for lagering, it is perfect for keeping kegs at the correct beer serving temperatures when not being used for fermentation.
Humm, there’s all kinds of things that will get in the way of this working. Off the shelf, the freezer probably has a timer to control the defrosting cycle. So cutting the power would essentially stop the timer making it hard to guarantee the freezer will go into a cooling cycle when ever powered up. Also, many (if not all) off the shelf house thermostats will include a back off timer so as not to cause undue stress on the cooling system. I think the average temperature will be obtainable. But I think the actual temperature will very depending on the randomness of some of these (now unwanted) features.
Did anyone look deeply into the thread and see if these issues were considered?