Cold crashing with blow off hooked up to keg to prevent suck-back

[Beerandgranite]

I just got around to adding a gas post to my fementer lid (7gal plastic bucket) to start implementing closed transfer/purge kegs with fermentation Co2, and it occurred to me i could use this setup for cold crashing as well. The plan is to :

• have the fermentor blow off into and purge a keg filled with starsan solution via gas post to gas post
• The purged starsan solution is forced out of the liquid post into a five gallon bucket in a way that it will submerge the line
• cold crash
• solution sucks back into the keg and not the fermenter
• blow out any star san from keg with co2
• closed transfer to purged keg

Any way to improve upon this?

 

[wsmith1625]

Sounds like a working solution. You could also just attach your CO2 line directly to your fermenter and cold crash. As the beer contracts and pressure drops, the regulator will add CO2 to compensate. Both methods will protect the beer from oxidation, so whichever works best for your setup.

 

[VikeMan]

There will be oxygen dissolved in the sanitizer in the bucket (and then the keg). That O2 will seek equilibrium with the headspace in the keg, which in turn is seeking equilibrium with the headspace in the fermenter, which in turn is seeking equilibrium with the beer. End result is O2 in the beer.

So if your goal is to eliminate O2 ingress while cold crashing, this would not be the way.