Cold crash vacume

1. You can make your blow off tube a lot longer.

2. You can use an S shaped airlock.

3. You can stop cold crashing.

All of them work. I prefer option 3.

 

I keg and then crash. Cold crashing in a fermenter with any type of standard airlock will cause O2 to be sucked in.

 

Even with O2 sucked in, there is still a blanket of CO2 on top of the beer. I use an S-airlock with no issues and have yet to have oxidized beer that I have cold crashed.

 

The blanket of CO2 will not stop the oxygen from diffusing into the beer. The signs of oxidation take time to develop.

Cheers!

 

A CO2 "blanket" in a fermenter won't keep O2 from reaching your beer. (See Fick's Law.) And if anything, the negative pressure that pulls in the O2 is also going to accelerate the mixing of the gases in the headspace.

That would be magic. Now if you say you haven't had beer oxidized to the point that you noticed it, that could be.

 

Not sure why people keep circulating this rhetoric of carbon dioxide magically stratifying and protecting their beer from other gases. Giovanni Badino disproved this six years ago. (1)(2). Stratification of gases can occur but requires a STATIC column of air several kilometers in height. I'm reminded of My Cousin Vinny every time this topic comes up and say to myself "Well perhaps the laws of physics cease to exist in your carboy!"
Whether or not you personally have experienced oxidized beer is hearsay, however I'm here to say that I have definitely experienced oxidized off-flavors due to cold crashing in a carboy with an S-shaped airlock.

(1.) G. Badino – The legend of carbon dioxide heaviness. Journal of Cave and Karst Studies, v. 71, no. 1, p. 100–107.
https://caves.org/pub/journal/PDF/v71/cave-71-01-100.pdf

(2) http://chemdaq.blogspot.com/2012/09/gas-stratification-is-not-relevant-to.html

 

Negative. As the small amount of fluid rises towards the carboy outside air will bubble up through in the same manner that CO2 bubbles out. A blow off tube placed in a container full of (insert whatever solution you use) will pull the fluid back until there is no more fluid at which point air will start to be pulled in.

Yes. Ideally, you won't rack large particulates into the keg in which case all of the stuff that settles is of a microscopic size. I have not had any clogs personally but I suppose it could happen if the yeast drops out and settles into a hard pack form.

 

Well, you have a couple choices here... Crash (in a keg with a slightly shortened dip tube) and then do a pressurized transfer to another keg, or live with a pint or two with some dregs in them. Either way, I've never had a clogged dip tube or poppet. But I'm also pretty careful not to pick up sediment when racking.

 

As proof of this folly, will you go stick your head in a chest freezer with fermenting beer? (please don't really do that)

 

A fermenting freezer has a high concentration of CO2 because it's being constantly produced, with nowhere to go except to fill the fermenter and freezer. All in accordance with the phenomenon behind Fick's law. If the freezer were left open, the same phenomenon would result in most of that CO2 diffusing out of the freezer.

 

I stand corrected! Good to know.

 

maybe that's what the two yutes thought . . .​

 

eventually...but in the context of homebrewing, not immediately or significantly if the fermenter is handled gently

 

Proper brewing techniques and science are fine and dandy. However, if you cold crash the fermenter and can't find anything wrong with your beer, then it doesn't matter to you unless you stop cold crashing your beer and notice a legitimate improvement.

Most of my beers are hoppy and completely consumed in less than 2.5 months from brew day. The early consequence of cold crashing a fermenter is premature hop fade. I want the hops to be bright until the last drop. Skipping the cold crash improved hop flavor and aroma stability. Cold crashing occurs in the keg or bottle. The keg will blow out the excess yeast with the first 6oz pour. If you want to put less yeast in the bottle, primary for 3 weeks.

 

I don't know what you mean by that. Diffusion starts immediately. And whether the impact to the beer's taste is significant is a matter of opinion.

I'm curious...would you consider moving a fermenter from a freezer to a tabletop (to create height for racking) to be a gentle process? And would you consider the cold crash "vacuum" (differential pressure, really) that sucks O2 into the fermenter to be gentle? How long do you suppose it would be before the O2 sucked in was evenly distributed throughout the headspace, even if the O2 was somehow magically injected into just the very top?

 

For the record, I don't siphon and I don't cold crash. I've also gone to 2 week primaries (from 3) to ensure more CO2 in suspension .

Yes, the way I do it in a bucket anyway...I would hate to try it again in a carboy though

It's funny how lately people worry about things that don't significantly impact/improve the quality of the homebrew...eg. closed xfer systems, stir plates, fermcap , and gadgets like refractometers, etc....IMHO...rant complete

 

Say what you will, but in almost every case where I've had something go wrong with my homebrew, oxygen was to blame.