Cold crashing and oxidation

[Ozwald]

How do conicals in pro breweries work when cold crashing? Do they just cap the conical, or is there something that actively feeds CO2, like a cask breather, as the pressure changes?

While I am not a pro brewer, and never have been, those that I have seen have either capped the tank, or more commonly moved to a bright tank with CO2 to crash and carbonate (just like you can do with a corny keg).

+1. That's what I was saying much earlier. They just pressurize the tank. Sometimes the conical, sometimes the bright tank. There's no need to make this issue so complicated.

[rossiski]

So after 9 pages of responses I am thinking to use my keg to cold crash in moving forward and pitch out the first couple pints. Has anyone experienced a clogged dip tube as a result of too much sludge in the bottom of the keg as a result of using this method?

[Afterlab]

The only clogged dip tubes I've had were due to hops. The vast majority of trub and break material should be easy enough to not siphon into the keg and cause a problem.

[Ozwald]

A good way to siphon off as much clear beer as possible is to tilt the carboy or bucket so everything settles more to one side. They sell wedges but you could easily just use a small section of 2x4 or a thickish book under one side. Just make sure it's not tilted too far to be unstable/unsafe. You only need one edge up an inch or 2.

I've never clogged a dip tube, but I have got a little bit of hop matter stuck in a poppet. It didn't affect it while pouring, but it made switching the keg rather "interesting".

Gelatin also helps. The little bit of stuff you do transfer over gels up, making it a bit easier to get out of solution & leaves some brilliantly clear beer in the process. There's a couple threads here on how to use it.

[cdburg]

In the spirit of homebrewer over-engineering, I put together my own attempt at solving for for oxidation when cold crashing. It's probably totally unnecessary, but it makes me feel a bit better, and makes moving beer out of the conical easier also.



I have a 3" tri clover fitting in the lid of my conical, so I bought a 3" tri clover plate with a 1/2" male NPT fitting in the center. From there, I use a 1/2" stainless elbow into a 1/2" NPT to 1/4 NPT reducer. That goes into a 1/4" NPT mini ball valve then a 1/4" NPT to 1/4" flare fitting. I then have an 1/4" flare corny post adapter and finally a liquid corny post (I should have gotten a gas post, but either will work in my set up).

It's probably unnecessary to have both the ball valve and the post, but I like the idea of the backup. I wanted all of the parts to be stainless, but I couldn't find the 1/4" FFL to NPT fitting in anything other than brass.



To use it, I hook up a corny liquid out fitting attached to some tubing that can run into a cup of sanitizer during fermentation. The fermenter is big enough that I don't get blow off. I don't think krausen and a liquid out fitting would work otherwise. After fermentation is done, I can remove the liquid out fitting and blow off tube, close the ball valve and drop the temperature. I can add CO2, as needed, at any time to equalize the pressure. I'll also use the same set up to push the beer out of the conical and into a keg.

[jonboris]

A couple months ago I started swapping in a solid bung for cold crashing. It creates a fairly significant vacuum after a 24/48hr ride at 34F. I immediately flush the headspace with CO2 after the vacuum draws in the ambient air.

Do you guys think it's building up enough vac pressure that I should be worried about popping a glass carboy?

[Ozwald]

A couple months ago I started swapping in a solid bung for cold crashing. It creates a fairly significant vacuum after a 24/48hr ride at 34F. I immediately flush the headspace with CO2 after the vacuum draws in the ambient air.

Do you guys think it's building up enough vac pressure that I should be worried about popping a glass carboy?

Sorry, I stopped paying attention to this thread quite a while ago.

It only takes a few PSI to bust a carboy. Normally people think of that as pressurizing it internally, but creating a vacuum is doing the same thing... the pressure is just pushing on the outside of the glass instead of the inside. I would assume it would withstand a few more PSI pushing externally as opposed to internal pressure, but I still wouldn't push it too far.

[drinker101]

Would a very long blow off tube mitigate the problem? Perhaps purged with Co2. How many litres are we talking about. Ive only recently started cold crashing and so Ive only been aware of this issue with my last couple of brews. Fortunately only spring water went back in my fermentor.

Cheers

d101