Cold Crash in the Carboy

[Mylo]

I may be super crazy about it, but I just cant make myself crash cool a carboy. You have to be pulling bacteria and at least 02 into your carboy, right? I always keg first then crash.

I use fritz's method (NY minds think alike), although brewinhard's method also works. As far as 02 is concerned, you are talking about a very miniscule volume during the chill down. Bacteria don't crawl or jump. They do, however, catch a ride on dust - which you are very unlikely to "suck" into your carboy covered with tinfoil. I've been doing this for years, and have no oxidation issues. You are WAY more likely to pick up O2 during the transfer - which you have to do anyway. I do a closed transfer to a completely purged corny (previously filled with starsan).


Mylo

[thatguy314]

I recently started crashing in the carboy before the keg to minimize the yeast dregs. I leave the airlock on. I've noticed when I do that, I do tend to get a little bit of starsan sucked in, which I'd much rather than oxygen. Sanitized foil and everything else won't prevent oxygen from coming in. I've noticed absolutely no flavor contribution from what I estimate to be about 2-5mls of starsan in 5.5 gallons (20819 ml) or wort. Given that it's about 0.02% of the beer, i think I'm ok. I imagine that's less starsan than will settle out when all the foam in your carboy settles down.

[siwelwerd]

You are WAY more likely to pick up O2 during the transfer - which you have to do anyway. I do a closed transfer to a completely purged corny (previously filled with starsan).

+1. Worry more about getting all the O2 out of your keg. A little O2 won't make a big difference over a short time with no agitation; agitating the wort as you transfer in an O2 rich environment can adversely affect it.

And carboy caps FTW.

[Hoppy Mad]

I am just about to keg my first lager in 8 yrs.
The local brewpub gave be a vial of WLP0838 and I made the Munich Helles
from BCS. After fermentation the brewer said to crash it on the yeast
and leave it for the same time as fermentation.

As the beer was already cold there was minimal starsan sucked into the fermenter.

just my 2cents worth.



Brendan

[edisonst]

I pull the airlock out and cover with sanitized cling wrap. The suck back makes a great seal. As far as bcmaui was saying about drying the rubber stopper. I have a 6 gal fermenter and a 6.5, I have 2 rubber stoppers that look the same but only will stick in one of the two fermenters. I usually ahve to try a stopper or two before I find the one that sticks(when wet). Maybe you have a 6 gal stopper for a 6.5 fermenter. I used to be frustrated by the same problem.

[Travisty]

I do tend to get a little bit of starsan sucked in, which I'd much rather than oxygen.

O2 could still get into the carboy by this method. If CO2 can get out by positive pressure inside the carboy, than O2 can get in when that pressure differential is reversed. It kind of a reversed bubbler then. If you were able to keep adding starsan to the airlock before the level of the outside column of starsan was sucked down below the holes in the middle piece of the airlock, then you might be able to avoid getting oxygen in the carboy.

I wonder just how much O2 gets pulled into a carboy during the chilling time. I know that quite a bit of liquid can be pulled up into a blowoff hose during that time, but I wonder if the amount of O2 in an equivalent volume of air is enough to really cause any problems. In one of the last session episodes, Chad talked about how he purges his hoses with CO2 prior to transfering beer due to the volume of air that he thinks can cause oxidation problems. If that bit of air would cause problems, then certainly the volume pulled into a carboy druing cooling could too, right? I realize that during transfering the beer is being agitated while the beer in the carboy isn't; and there's alos a blanket of CO2 over the beer in the carboy so maybe the comparison isn't valid.

[Magilla]

I use foil. I can't imagine that the little bit of O2 sucked in will have any effect (especially since air is only 20% O2 and 78%+ N2). To each their own, I suppose.

[crupp]

I'm laughing because I just had something similar happen. I wasn't cold crashing, though. I was emptying my conical for the first time. When I opened the ball valve and ran the beer into my keg, I pulled about a pint's worth of starsan out of my blow off into my conical...duh, right? Stooped vacuum!

Do you think you could use a carboy cap and a check valve when crash cooling a carboy to prevent the liquid from entering the beer? Just thinking out loud here…