I tried the recipe for the 90 minute IPA clone that I received from BYO magazine but there is one thing I do not understand about the recipe. The last part of the recipe goes as follows: Dry hop in secondary fermenter at 71 degrees for 3-5 days, then cool to 32 degrees. Can anyone tell me what they mean by cooling it to 32 degrees because I dont quite understand what they mean to do here or when exactly to cool it.