Lagering Temperature Fluctuations

[lawyerjim]

I have a large commercial refrigerator that I would like to use for lagering. When the thermostat is set to 35 degrees, the air temperature inside the refrigerator fluctuates between 31 and 39. I know the temp of the beer will not rise and fall as fast as the air it is in but, will this be a problem?

 

[thadass]

Is this using a thermostat built into the refrigerator? If so it might be worthwhile to use an external controller like many others do for fermentation chambers/kegerators.

 

[BigFloyd]

Is this using a thermostat built into the refrigerator? If so it might be worthwhile to use an external controller like many others do for fermentation chambers/kegerators.

Yep. For a small expenditure, you can rig that up with an STC-1000 control outlet box and keep the temp very steady at just where you want it.

 

[SpeedYellow]

An 8F differential is pretty bad. That said, I don't think we can give you a definite answer with what you've given us. For example, if it insulates poorly then this 8F swing may happen over such a short time that the beer temp would be unaffected. Why not just toss in a gallon of water and take the temp periodically? Better would be 5 gals, but that's kind of a hassle.