Johnson A421 Digital Temperature Controller

The Digital Temp Controller operates by overriding the internal thermostat in a refrigerator or freezer and gives the brewer greater control over the fermentation. Precise control of fermentation temperature is one of the most beneficial things you can do to improve your home brew beer.It is also ideal for controlling the serving temperature of your kegerator or keezer. The digital controller has a digital display with adjustable differential. It can be used to heat or cool a fermentation environment. When hooked up to a refrigerator, it turns the compressor on when the ambient temperature rises above your programmed temperature; when hooked up to a heater, it activates when the temperature drops too low. A sensor probe monitors the temperature inside while the readout displays it in either Fahrenheit or Celsius. This is the ideal choice for lager brewers who include a diacetyl rest in their fermentations or for ales like altbier or Kolsch that require fermentation temperatures in the