What temperature do you cold crash at?

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petrolSpice

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So what temperature is everyone using for cold crashing?

I use 1C / 33.8 F

I realize since there's alcohol in the beer I could go below freezing but it's nice to have a little buffer.
 
I'm using a swamp cooler with 1/2 gallon ice bottles, so this time of year, I'm happy to get her down to 40*f or below. In the winter, I'll let her go down to sub-32*f. The water may freeze but the beer usually doesn't(don't ask me about my bock from 2 years ago)
 
Thats a fine temp. Cold crashing and gelatin are staples in my homebrew. Allows you to clear beer pretty quickly. And i like to drink quick/young/fresh beer. You can make simple and moderate gravity beers in 2 weeks or less with a keg. I'm trying to get my routine down to 10 days. 5-6 days primary, cold crash/gelatin 2-3 days, force carb 1 day. The beers been pretty darn good especially with the hops, considering i only use 2 oz for a 5 gallon batch. I figure if i waited longer the hop flavour - which is all i'm interested in, i don't care about the "nose" - would be non-existent.
 
I don't cold crash because it would back-suck air and cause oxidation (#1 home brew off flavor after poor temperature control). The problem is real!

I keg it, chill it, and after a few days pour off half a pint of sludge.
 
I don't cold crash because it would back-suck air and cause oxidation (#1 home brew off flavor after poor temperature control). The problem is real!

I keg it, chill it, and after a few days pour off half a pint of sludge.

Cold crash under positive pressure. Easy in a conical.... with carboys I used to just fill balloons and attached them to the top/
 
I don't cold crash because it would back-suck air and cause oxidation (#1 home brew off flavor after poor temperature control). The problem is real!

I keg it, chill it, and after a few days pour off half a pint of sludge.

With the heavier CO2 sitting on top of the beer from fermentation the air would never touch the beer.

I use a blowoff tube so when cold crashing it just sucks up fluid through the tube. The tube is long enough so the fluid never enters the beer. I use vodka just in case it does.
 
With the heavier CO2 sitting on top of the beer from fermentation the air would never touch the beer.

This is a myth. There is substantial mixing going on in the gas.

I use a blowoff tube so when cold crashing it just sucks up fluid through the tube. The tube is long enough so the fluid never enters the beer.

Even if you don't suck the water in, the FV will be under a slight vacuum. When you unhook the blow off tube you'll suck air right in.

I use vodka just in case it does.

The vodka will contain dissolved oxygen.


I can only think of a few ways to avoid oxygenating the fermented beer:
1. Use an FV that is capable of holding some pressure (few PSI). Cold crash with pressure applied via an external source (CO2 tank).

2. Use an FV that is capable of holding pressure (depends on temp but this is in the range of 10-20 psi). Use a spunding valve at the end of fermentation to build enough pressure so that when you chill it, the pressure is still high enough to be positive.

3. Don't crash it in the FV. Crash it in the keg, with external pressure applied. Essentially #1.
 
Take a look at this thread.... Lots of good easy options for crashing in conicals. I show a picture of my old balloon method with carboys and daytripper shows a much much better carboy method here .

There is a lot of talk recently about oxidation for a good reason..... cold crash without positive pressure and there is 100% chance the beer is oxidized beyond generally acceptable levels.
 
So what temperature is everyone using for cold crashing?

I use 1C / 33.8 F

I realize since there's alcohol in the beer I could go below freezing but it's nice to have a little buffer.

A 5% alcohol beer begins to freeze at 28F so there's little chance of anything going wrong with your beer if cold crashing at 32F, which is approximately the temperature I use give or take +-2 degrees.
 
Brewing trends are more changeable than teenagers ........ so people are now not cold crashing in carboys? :)

I don't think anyone is saying that you shouldn't cold crash in carboys.

However, I also don't think anyone is saying that oxidation after fermentation is OK. If you ignore myths :ban: like stable "CO2 blankets" then you have to come to the conclusion that some sort of positive CO2 pressure must be applied to keep air (O2) suckback into the fermenter from happening.
 
So just when I'm about to pick up a freezer for a ferm chamber and I get the idea, hey, now I will easily be able to cold crash I read this thread. Not that I need to, using Whirlfloc, 3 weeks in primary, and less than 2 weeks in the bottle my brew is damn clear.
 
I don't think anyone is saying that you shouldn't cold crash in carboys.

However, I also don't think anyone is saying that oxidation after fermentation is OK. If you ignore myths :ban: like stable "CO2 blankets" then you have to come to the conclusion that some sort of positive CO2 pressure must be applied to keep air (O2) suckback into the fermenter from happening.

This begs the question -- how does one apply positive co2 pressure to a carboy?

.. and how does this oxygenation risk stack up vs exposure during bottling?

I guess I am trying to get a gauge on how much of this is idealism vs realism in terms of what new brewers can achieve.

It does seem like a lot of folk around here are crashing beer in carboys ... are they wrong to?
 
So just when I'm about to pick up a freezer for a ferm chamber and I get the idea, hey, now I will easily be able to cold crash I read this thread. Not that I need to, using Whirlfloc, 3 weeks in primary, and less than 2 weeks in the bottle my brew is damn clear.

This is me in a nutshell -- have freezer, why not crash? .... and then this thread ... :fro:
 
Check out the link I placed earlier in the thread for another thread that has a couple solutions. With boddling the carbonation will use some if the DO but I wouldn't count on all of it
 
I cold crash at 35*F. I keg, purge with CO2, cold crash, fine, then carb and drink.
 
I hook up a c02 service line to my ssbrewtech conical. Add 2 lbs of pressure, cold crash to 32 over 24 hours and hold it until I use the c02 to push it into c02 purged kegs. Before I had the conical I would cut an inch off my pickup tube and crash in my kegs under 12.5 lbs of c02. Before that I put carboys in the keezer and made sure I had a long blowoff tube and clean sani. To be perfectly honest they all work and I never have noticed cardboard in my beer. I did have problems when I was using buckets.

We have three bjcp National judges in our club and they laugh at my set up. They all use carboys or speidel jugs and don't really worry about it for what it's worth! They do drink my beers when we have tastings so I'd hear about it if something went wrong. Carry on mug:)
 
What if you replaced the airlock on your carboy with a solid stopper when cold crashing?
 
If you are cold crashing in order to turn 2 week beer, your beer likely won't be around long enough for any oxidation to be noticeable.

The potential for it to occur is definitely there. However, if a beer is going to be around long enough for oxidation to become apparent, then you really didn't need to rush things along by cold crashing. Letting it drop clear naturally would have been fine.

Don't let science scare you into ignoring common sense.
 
I'll counter some other antidotal evidence here and say that when I moved my process from carboys taking a minimum amount of effort (balloons and pushing with co2) to conicals with positive pressure cold crash, every effort to purge and limit co2 uptake there was a taste and color difference noticeable immediately upon kegging.


It's been pointed out to me by some of the people on the German brewering forum that the food grade co2 at 99.9% pure had enough oxygen present to go against the recommendations for force kegging quality, potentially putting the do above the recommended limited by itself
 
I'm baffled, I really am. I cold crash and use gelatin on every batch I've done for the past 4 1/2 years. I've never experienced a suckback. Granted I'm using a swamp cooler and ice bottles(or ambient temp. in the winter) instead of a refrigerator, but the temp gets down to 40-45 in the summer and 30-35 in the winter. I also use the 3 piece airlocks and don't see how it would be possible for them to get suckback. The S type, yes I can see that. I'm happy to ask "What am I missing"?
 
I'm baffled, I really am. I cold crash and use gelatin on every batch I've done for the past 4 1/2 years. I've never experienced a suckback. Granted I'm using a swamp cooler and ice bottles(or ambient temp. in the winter) instead of a refrigerator, but the temp gets down to 40-45 in the summer and 30-35 in the winter. I also use the 3 piece airlocks and don't see how it would be possible for them to get suckback. The S type, yes I can see that. I'm happy to ask "What am I missing"?

I'm the same. I never get suck back either. Maybe a small bit - not sure really - but never the whole airlock. I crash at ~32F in a fridge.

Its not an issue to me.
 
If you are not sucking sanitizer through the airlock or at least partially up the blue of tube then you are either pulling a vacuum on the carboy or leaking air around the connection.
 
I hook up a c02 service line to my ssbrewtech conical. Add 2 lbs of pressure, cold crash to 32 over 24 hours and hold it until I use the c02 to push it into c02 purged kegs. Before I had the conical I would cut an inch off my pickup tube and crash in my kegs under 12.5 lbs of c02. Before that I put carboys in the keezer and made sure I had a long blowoff tube and clean sani. To be perfectly honest they all work and I never have noticed cardboard in my beer. I did have problems when I was using buckets.

We have three bjcp National judges in our club and they laugh at my set up. They all use carboys or speidel jugs and don't really worry about it for what it's worth! They do drink my beers when we have tastings so I'd hear about it if something went wrong. Carry on mug:)

Love to see how you have this setup. I have a couple ss conical and want to start doing this but don't know where to start. Thanks.
 
I do similar with a pressure gauge and valve added. also using a low pressure propain regulator on the cold crash CO2 line prevents having to have a low pressure r CO2 egulator.
 
If you are not sucking sanitizer through the airlock or at least partially up the blue of tube then you are either pulling a vacuum on the carboy or leaking air around the connection.

Not sure man, i never had to think about it. I guess the "connection" is leaking.

I fill my 3 piece air lock around 1/4 - 2/3 and it doesn't suck back. In all 3 of my vessels. Plastic bucket, 6 gal glass carboy and an old 5 gal green glass wine bottle - when it was bought it was full of red wine.

However, i'm pretty sure if the carboy was "pulling" a vacuum the water would leave the air lock.
 
Ok, i'm thinking out loud here on a forum.

Probably if i cold crashed a carboy that was right to the riim. The airlock i think it might suck back in 5-10 hours. But i don't ever have a full carboy because i crash in the primary. So of course its not full, campared to if you topped up a secondary of wine.

Anyhow bottomline i don't get suck back whiile cold crashing. If its some majic i want to know more.
 
I'm baffled, I really am. I cold crash and use gelatin on every batch I've done for the past 4 1/2 years. I've never experienced a suckback. Granted I'm using a swamp cooler and ice bottles(or ambient temp. in the winter) instead of a refrigerator, but the temp gets down to 40-45 in the summer and 30-35 in the winter. I also use the 3 piece airlocks and don't see how it would be possible for them to get suckback. The S type, yes I can see that. I'm happy to ask "What am I missing"?

Isn't it silly? The only thing that can suckback is the little liquid you can have over the pipe - that will be gone in a few drops lol

I'm missing something too friend with this one.
 
Anyhow bottomline i don't get suck back whiile cold crashing. If its some majic i want to know more.

If your vessel is sealed and you cold crash, you are 100% going to generate a lower pressure in the vessel. Simple ideal gas law in action. How that negative pressure equalizes is the question.

Even if you don't suck liquid back, the moment you relieve the vacuum, air will rush into the carboy.
 
If your vessel is sealed and you cold crash, you are 100% going to generate a lower pressure in the vessel. Simple ideal gas law in action. How that negative pressure equalizes is the question.

Even if you don't suck liquid back, the moment you relieve the vacuum, air will rush into the carboy.

Relieve the vacuum?

And of ****ing course when you cool something from 20 to 0 in a few days it will change the pressure!

Carboys and buckets are not vessels.
 
I've decided to not give a ****. As soon as I stop my crash I am bottling anyway and the beer will be no more or less exposed to oxygen then in my bucket than it will be post crash as air equalizes.
 
Just to add to the discussion,What about cold crashing in a ferm chamber that's filled to the top with co2 after fermentation to the point you cant stick your head in the chest freezer.Would that be considered safe to cold crash in?Wouldnt the bucket only be sucking in Co2??
 
Carboys and buckets are not vessels.

Since when?

For the record, oxidation doesn't make a beer undrinkable. It does impact the flavor though, especially after extended aging. If you cold crash and are totally happy with your product, go for it.

Going through all the effort to make a low oxygen beer isn't for everybody.
 
Just to add to the discussion,What about cold crashing in a ferm chamber that's filled to the top with co2 after fermentation to the point you cant stick your head in the chest freezer.Would that be considered safe to cold crash in?Wouldnt the bucket only be sucking in Co2??

If it were a pure CO2 environment then you'd be ok. But how would you go about ensuring your ferm chamber doesn't have any oxygen in the ambient air?
 
DP How are you purging the kegs? With the lid open like that you are still getting some O2 uptake. To transfer I do similar but:

  • Clean two kegs that I have modified with a CO2 stone as "brite tanks"
  • Fill the first keg with a StarSan solution
  • Push the StarSan using a transfer line and CO2 to the second keg
  • Push the StarSan into a third keg or a bucket
  • Assemble sight glass, T, two barbs and keg QD's as shown
  • Fill the assembly with StarSan and sanitize connection on conical
  • Hook the QD to one of the pressurized kegs OUT, most of the Starsan in the assembly will blow out (hopefully into the bucket:ban:). Hook up the second QD to the second keg OUT. As the CO2 is still pushing out connect to the conical. Now there is no air in the line
  • Hook a QD to each kegs in port
  • Apply slight pressure to the conical and open the drain port.

To hold pressure when I'm cold crashing I use a propane regulator to drop to 1-2psi.

**I should note that I have been striving for a low post fermentation dissolved oxygen content for a while. With the recent release of the german brewing O2 paper and my own readings of Kunze (and other sources) I am not satisfied with my setup. I am currently contemplating steam+nitrogen purging and spudding as well as other changes.

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