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Author Topic: Length of cold crash?  (Read 4402 times)

Offline Richard

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Re: Length of cold crash?
« Reply #15 on: November 12, 2019, 09:38:02 am »
   I just put a stopper in the airlock hole, my FV's seal up well enough to hold the small amount of vacuum created by crashing.

My PET carboy holds pressure fine with a stopper in place of the airlock, but the sides buckle in under the negative pressure. After seeing that happen a couple of times I became concerned that the buckling and cold temps could make it brittle and that it would eventually crack.
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Offline goose

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Re: Length of cold crash?
« Reply #16 on: November 12, 2019, 12:39:43 pm »
When I cold crash my beers,  I first do a room tempertture closed transfer to the keg like Brewbama does, put the keg in my lagering freezer set at 33 degrees, put 10 lbs of CO2 pressure on it, and let it sit for w week or so.  If I want to drink the beer a bit sooner, I increase the pressure to 15 lbs and it's done in about 3 days.  That way I don't get any "suck back" as the beer cools in the lagering freezer.

If the beer is something like a Saison, I put more pressure on it to make it effervescent and play the draft line game to eliminate foaming when it is poured.  There are some good carbonation charts in thee literature that will give you insight on how many volumes the beer will absorb at specified temperatures.

Just my .02
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Offline Robert

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Re: Length of cold crash?
« Reply #17 on: November 12, 2019, 12:53:15 pm »


I put in a piece of stainless tubing connected to a standard "Happy Birthday" mylar baloon.

Richard, this is a great execution of a popular but often flawed technique to maintain a closed environment.  I often see references to balloons attached to fermenters with silicone tubing, which rather defeats the purpose as it is about as oxygen permeable a material as one could find (vinyl is not a great deal better in this regard.)  On another forum I saw a long thread where people were mulling over ways to wrap the tubing in something to provide an oxygen barrier, or find some other less permeable plastic or PTFE type tubing.  Stainless is such a simple, cheap, and obvious choice! 

(But I bet your local party store could provide a mylar balloon bearing a more appropriate theme than "happy birthday."  Surely some beer mug graphics or the like?)
Rob Stein
Akron, Ohio

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Offline Richard

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Re: Length of cold crash?
« Reply #18 on: November 12, 2019, 01:55:38 pm »
The piece of stainless I used was especially cheap because it was a scrap left over from a different project, so essentially free. It also fits in the same size hole as my airlock, which is convenient.

As far as the balloon, I used a sharpie to change it to "Hoppy Birthday".
Original Gravity - that would be Newton's

Offline Barbarian Brewer

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Re: Length of cold crash?
« Reply #19 on: November 19, 2019, 12:19:41 pm »
How necessary is the CO2 replacement when cold-crashing?

I like the way cold-crashing compacts the trub which allows me to extract more sediment free beer into the bottling bucket.  Since I don't have a CO2 tank so I just replace the airlock with a starsan soaked paper towel and drop the temp on my chest freezer to 34 F.  How much might the O2 introduced into the head space affect my beer?  I generally make pretty good beer but I wonder whether this may be contributing to those less satisfying beers.

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Offline Robert

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Re: Length of cold crash?
« Reply #20 on: November 19, 2019, 12:23:23 pm »
You will definitely be getting some oxidation.  There have been a number of threads around here on how people use a balloon on the airlock to collect CO2 during fermentation and then this will resupply the  headspace during cooling instead of drawing in air.
Rob Stein
Akron, Ohio

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Online denny

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Re: Length of cold crash?
« Reply #21 on: November 19, 2019, 02:18:37 pm »
It's only necesary if you think it is.  For some it's more important than others
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Offline Barbarian Brewer

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Re: Length of cold crash?
« Reply #22 on: November 19, 2019, 06:07:46 pm »
You will definitely be getting some oxidation.  There have been a number of threads around here on how people use a balloon on the airlock to collect CO2 during fermentation and then this will resupply the  headspace during cooling instead of drawing in air.

<Lightbulb>  Now I get it.  Thanks @Robert!  That's the part I was missing.
"People who drink light 'beer' don't like the taste of beer; they just like to pee alot." -Capital Brewery, Middleton, WI

Offline charlie

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Re: Length of cold crash?
« Reply #23 on: November 19, 2019, 06:58:06 pm »
Why bother? If you're kegging an ale, and particularly if it's a dry hopped ale, then you want to get on it ASAP.

If I could be said to cold crash then I cold crash in the keggerator, and it's ready to drink after 2 or 3 days. I have noticed no ill effects from this procedure in 11 years of all-grain brewing.

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Offline Barbarian Brewer

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Re: Length of cold crash?
« Reply #24 on: November 19, 2019, 07:20:18 pm »
It's probably not worth the effort but, but it's a fascinating idea.  I think I'm going to give it a try and see if it makes a difference.
"People who drink light 'beer' don't like the taste of beer; they just like to pee alot." -Capital Brewery, Middleton, WI

Offline Richard

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Re: Length of cold crash?
« Reply #25 on: November 19, 2019, 10:28:47 pm »
It really is very little effort once you have the equipment fabricated. I put a balloon in place today in only a couple of minutes, including sanitizing the stainless feed tube. I bottle all my beer and don't keg, so I don't have any CO2 tanks around. The only CO2 I have is the stuff I make during fermentation, so I take a bit of care to capture it and re-use it.
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Offline jtoots

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Re: Length of cold crash?
« Reply #26 on: November 20, 2019, 06:13:46 am »
late to the conversation here but a couple thoughts that i don't see brought up yet:
-one reason to keep the crash a bit more gradual is to save the compressor of your chest freezer (if that's how you're doing it). if i try to chill 10 gallons in one go i'll definitely kill my freezer, so i go about 5 deg C at a time.
-personally i don't get clear beer until a couple weeks of cold crashing.

-now that i'm reading all this input about oxidation i might stop cold crashing in the carboys and just do it in my kegs.