I have two of the 7G Ss Brew Buckets with FTSs cooling systems and have been using frozen water bottles in a cooler. Recently I bought a glycol chiller to replace the water bottles...thank goodness!
Anyway, I had always racked to keg at fermentation temps, then cold crashed on gas in an ATC outfitted freezer. Now that I have this glycol chiller, why not go ahead and crash in the bucket and let some yeast and trub settle out prior to racking.
Problem is that a heck of a suction is formed when going from 65F down to 35F in an hour. I mean a WHOLE jug of starsan gets sucked up if not careful...live and learn. Glad I did an experimental test batch to learn on.
I need to apply positive CO2 pressure in the headspace to offset the negative pressure created in the fermenter. What if I apply light CO2 pressure thru the BO tube, then clamp off the tube while crashing? Or...fill a bread bag with CO2 (Mongoose33 good idea), tape it to the BO tube and use that for a bladder to draw from? Just concerned that O2 will get in the fermenter if this is not done carefully.
Are there other techniques I may be overlooking? Thanks!!