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General Category => General Homebrew Discussion => Topic started by: majorvices on January 08, 2010, 06:55:34 PM

Title: Carboy Oxidation - sure doesn't take long!
Post by: majorvices on January 08, 2010, 06:55:34 PM
Well, I hurt my back a few weeks ago and was not able to move the carboys out of the deep chest freezer (a kolsch) so rather than transfer to carboy I just turned the temp down to 32 on the freezer. Well, the temp changed sucked the air lock water into the carboy so I refilled it. Today when I finally went to keg the beer I noticed the air lock was low again, no big deal I thought. well, the beer is partially oxidized. Not so bad I can't drink it but certainly has some of that sherry notes. It is even darker than I expected. I guess I was thinking that at those temps the beer would be alright - guess not. this is one reason I don;t secondary in the carboy. Guess if you do you might invest in a dry air lock.
Title: Re: Carboy Oxidation - sure doesn't take long!
Post by: ndcube on January 08, 2010, 07:01:02 PM
How much head space was there?
Title: Re: Carboy Oxidation - sure doesn't take long!
Post by: Kaiser on January 08, 2010, 07:07:39 PM
Guess if you do you might invest in a dry air lock.

Would that dry airlock be a true one-way valve? Since water got sucked in there was low pressure in the head space and not enough CO2 from the beer to fill it.

When the airlock prevents air from entering the head space and leaves the head space pressure lower than ambient pressure you have to make sure that the stopper seal is airtight. Otherwise air will still find its way into the head space.

I wonder, to what extend this problem exists with cold crashing a completely fermented beer in the primary. Here the head space CO2 might be at equilibrium with the beer and no more CO2 is created. As the pressure drops CO2 will be absorbed back into the beer and the head space CO2 volume also contracts. As a result air has to move into the head space.

Kai
Title: Re: Carboy Oxidation - sure doesn't take long!
Post by: blatz on January 08, 2010, 07:11:43 PM
Keith - was your wife's back hurt too??

That sucks man - unfortunately (as you know) that's one of the worst styles for your mishap to have happened to due to the delicate nature of the flavor. 

Am curious about this "dry air lock"?
Title: Re: Carboy Oxidation - sure doesn't take long!
Post by: Beertracker on January 08, 2010, 07:19:30 PM
It happens to the best of us, but lesson learned. Sorry to hear about your back. Back pain is truly a pain, as my chiropractor can attest! At least he drinks better beer since meeting me. :D
Title: Re: Carboy Oxidation - sure doesn't take long!
Post by: majorvices on January 08, 2010, 07:47:36 PM
How much head space was there?

Plenty - this wasn't a secndary. It was a primary. I only "secondary" in kegs. I prefer to call it bright tank though.  ;)

Kai - yeah, at the very least I would really worry about carboy breakage.

Blatz - What the hell, man, my wife can't lift a full carboy!!! To be honest, it isn't really that bad yet. Drink it quick and keep it cold. Won't be sending it out though. Plus, my wife probably won't bat an eye while she drinks it. I mostly brew kolsch for her... mostly.

As far as the dry air lock there was an article how to make one in BYO a few years ago with McMasterCarr parts. I'll see if I can find it. Still, nothing beats stainless under pressure.

Title: Re: Carboy Oxidation - sure doesn't take long!
Post by: Thirsty_Monk on January 08, 2010, 07:50:07 PM
Has it the Kolsh you brew with FWH?
What are your observations?
Title: Re: Carboy Oxidation - sure doesn't take long!
Post by: majorvices on January 08, 2010, 07:51:17 PM
It happens to the best of us, but lesson learned. Sorry to hear about your back. Back pain is truly a pain, as my chiropractor can attest! At least he drinks better beer since meeting me. :D

Yeah, I learned my lesson. Call someone to help next time. I had thought about it but figured the beer would be fine. Really though, its not undrinkable. Just not as good as it should have been. And, for me anyway, more core work is in order. I just can't deal with back pain. It's like hitting the brakes in mid-life. Still not fully over it yet. Sucks! :(
Title: Re: Carboy Oxidation - sure doesn't take long!
Post by: majorvices on January 08, 2010, 07:53:12 PM
Has it the Kolsh you brew with FWH?
What are your observations?

Yep. damn it! I was goingt o wait until it was carbonated to give my impressions. I think I can taste around the flaw. I wasn;t disappointed in the outcome. That said, it was an expensive batch, hop wise. Don't know I will go all FWH on many beers.
Title: Re: Carboy Oxidation - sure doesn't take long!
Post by: ndcube on January 08, 2010, 07:58:06 PM
Assuming I did the math / science right...  and it's been a while so I could be wrong.

If your secondary carboy is filled with 4.75 gal of beer and .25 gal of CO2 then you will lose 10.35 teaspoons of CO2 volume in the headspace and 3 teaspoons of beer volume (neglecting alcohol content and assuming a drop from 60F to 32F).

This is just over a quarter of a cup.  Is that enough air going in to oxidize the beer (assuming your airlock doesn't dry out completely as major's did).

What else am I missing in my logic?  More gas is dissovled at lower temps?  Do you take the whole carboy volume into consideration for CO2 and not just the headspace?
Title: Re: Carboy Oxidation - sure doesn't take long!
Post by: Thirsty_Monk on January 08, 2010, 08:02:07 PM
Don't know I will go all FWH on many beers.

I did about 6 batches with FWH just to make sure.
I would agree with you.
I do not think I will be FWH any beer.
I just got kind of harsh lingering bitterns that I did not enjoy.
Title: Re: Carboy Oxidation - sure doesn't take long!
Post by: majorvices on January 08, 2010, 08:05:34 PM
Assuming I did the math / science right...  and it's been a while so I could be wrong.

If your secondary carboy is filled with 4.75 gal of beer and .25 gal of CO2 then you will lose 10.35 teaspoons of CO2 volume in the headspace and 3 teaspoons of beer volume (neglecting alcohol content and assuming a drop from 60F to 32F).

This is just over a quarter of a cup.  Is that enough air going in to oxidize the beer (assuming your airlock doesn't dry out completely as major's did).

What else am I missing in my logic?  More gas is dissovled at lower temps?  Do you take the whole carboy volume into consideration for CO2 and not just the headspace?

Man, I don't know about math and all that. I'm a graphic designer for heaven's sake.  ;) Here's what I do know. It was about 5.5 gallons of beer and a 7 gallon carboy (two of 'em actually). Lots of head space. The air lock was low and it was this way for at least 2 weeks. I get some sherry notes in the beer. That's the bottom line of it.
Title: Re: Carboy Oxidation - sure doesn't take long!
Post by: majorvices on January 08, 2010, 08:07:42 PM
Don't know I will go all FWH on many beers.

I did about 6 batches with FWH just to make sure.
I would agree with you.
I do not think I will be FWH any beer.
I just got kind of harsh lingering bitterns that I did not enjoy.


For me the bitterness was very nice and smooth. No harshness. I liked the beer very well. But I needed 1/2 pound of hops to get the effect and I would rather use magnum at boiling and crystal at the 20 min. mark for the flavoring and use much less hops in the future. Might try a few more tests, we'll see.
Title: Re: Carboy Oxidation - sure doesn't take long!
Post by: Kaiser on January 08, 2010, 08:13:16 PM
What else am I missing in my logic?  More gas is dissovled at lower temps?  Do you take the whole carboy volume into consideration for CO2 and not just the headspace?

CO2 absorption by the beer is key. At 60 the beer can hold 1.0 volumes of CO2 at atmospheric pressure. At 32 its 1.6 vlumes. This is a difference of ~0.6 volumes. In the end 5 gal of beer had the ability to suck up 3 gallons of CO2. That’s way more than what your head space provides.

Most of the time that may not be an issue since even  finished beer is likely to be oversaturated with CO2 (i.e it holds more than is able to hold at its temperature). And there might also be some residual fermentation that still produces CO2.

I transfer my beers (ales and lagers) to corny kegs before they completed fermentation. Then I give them some time to complete fermentation in the closed keg before I cold crash them. Finally the clear beer is transferred to a serving keg. I don’t like carboys for secondary and I also cannot fit as many in my lagering chest.

Kai
Title: Re: Carboy Oxidation - sure doesn't take long!
Post by: majorvices on January 08, 2010, 08:17:55 PM
Beer was completely flat at transfer. And much darker than usual. 'Course I did use a touch of munich in the recipe this time.
Title: Re: Carboy Oxidation - sure doesn't take long!
Post by: Kaiser on January 08, 2010, 08:28:20 PM
. And much darker than usual.

Oxidation does that. I once force oxidised and force aged a Helles to see what oxydation taste like and it was also much darker.

Kai
Title: Re: Carboy Oxidation - sure doesn't take long!
Post by: blatz on January 08, 2010, 08:44:46 PM
Don't know I will go all FWH on many beers.

I did about 6 batches with FWH just to make sure.
I would agree with you.
I do not think I will be FWH any beer.
I just got kind of harsh lingering bitterns that I did not enjoy.


amen to that!!  I gave it up 2 years ago and then recently tried it again to see if I still felt the same - yep, no thanks! 

I think its gained popularity b/c Denny enjoys it and its a key method in his beers.  I think its somewhat rare (from what I understand) on the pro scene.  The pros I talk to scrunched their faces at it for the "strange, lingering" (their words) bitterness it leaves. 


Blatz - What the hell, man, my wife can't lift a full carboy!!! To be honest, it isn't really that bad yet. Drink it quick and keep it cold. Won't be sending it out though. Plus, my wife probably won't bat an eye while she drinks it. I mostly brew kolsch for her...

well, you've got big guns and are a workout fiend, I figured your wife might be the equivalent of gillian michaels or something  ;)

seriously though, I woulda had fun with my wife and with a straight face, brought her in the garage and asked her to lift the carboys out - purely to see the Are you f-ing insane??? look on her face. 
Title: Re: Carboy Oxidation - sure doesn't take long!
Post by: Kaiser on January 08, 2010, 09:01:57 PM
I enjoyed the few beers I FWHed. It made a nice Pilsner with an authentic aroma and flavor profile. I did not notice a harsh bitterness but I'll pay more attention to that next time I use FWH.

Kai
Title: Re: Carboy Oxidation - sure doesn't take long!
Post by: ndcube on January 08, 2010, 09:15:36 PM
CO2 absorption by the beer is key. At 60 the beer can hold 1.0 volumes of CO2 at atmospheric pressure. At 32 its 1.6 vlumes. This is a difference of ~0.6 volumes. In the end 5 gal of beer had the ability to suck up 3 gallons of CO2. That’s way more than what your head space provides.

I don't usually leave any headspace but I guess that's immaterial.

Just because the beer can suck up .6 volumes of CO2, will that actually happen let alone bring O2 along with it?

Title: Re: Carboy Oxidation - sure doesn't take long!
Post by: denny on January 08, 2010, 09:38:51 PM
As far as the dry air lock there was an article how to make one in BYO a few years ago with McMasterCarr parts. I'll see if I can find it. Still, nothing beats stainless under pressure.



Back in the days when I used carboys, I just put a piece of foil tightly rubber banded around the opening.  I assume there wasn't much CO2 escaping at 32F, so that kind of thing should work for you if you need to do it in the future.
Title: Re: Carboy Oxidation - sure doesn't take long!
Post by: Kaiser on January 08, 2010, 10:06:24 PM
Just because the beer can suck up .6 volumes of CO2, will that actually happen let alone bring O2 along with it?

Because it doesn't have a supply of 3 gal the following will happen. As the CO2 is consumed by the beer its replaced by air. That air dilutes the CO2 and the CO2 partial pressure falls. Less CO2 partial pressure less ability for the beer to hold CO2. At some point there will be an eqilibrium where the beer has all the CO2 it can hold while the head space has just enough CO2 to create a CO2 pressure that matches what the beer needs to hold its CO2. One can write this equation and solve it but I don't think that this is necessary.

Kai
Title: Re: Carboy Oxidation - sure doesn't take long!
Post by: majorvices on January 08, 2010, 10:24:38 PM

I don't usually leave any headspace but I guess that's immaterial.

Just because the beer can suck up .6 volumes of CO2, will that actually happen let alone bring O2 along with it?



How do you "not leave any head space" in the primary???  :-\
Title: Re: Carboy Oxidation - sure doesn't take long!
Post by: majorvices on January 08, 2010, 10:26:27 PM

seriously though, I woulda had fun with my wife and with a straight face, brought her in the garage and asked her to lift the carboys out - purely to see the Are you f-ing insane??? look on her face.  

Come to think of it you kinda got that response from me.  ;)
Title: Re: Carboy Oxidation - sure doesn't take long!
Post by: ndcube on January 08, 2010, 11:20:58 PM

I don't usually leave any headspace but I guess that's immaterial.

Just because the beer can suck up .6 volumes of CO2, will that actually happen let alone bring O2 along with it?



How do you "not leave any head space" in the primary???  :-\

Sorry for the confustio. I'm talking about secondaries.
Title: Re: Carboy Oxidation - sure doesn't take long!
Post by: babalu87 on January 09, 2010, 03:57:11 AM
I enjoyed the few beers I FWHed. It made a nice Pilsner with an authentic aroma and flavor profile. I did not notice a harsh bitterness but I'll pay more attention to that next time I use FWH.

Kai

If that was one of the Pilsners you gave me last Spring your statement is seconded

A truly GREAT beer
Title: Re: Carboy Oxidation - sure doesn't take long!
Post by: Kaiser on January 09, 2010, 11:35:11 PM

If that was one of the Pilsners you gave me last Spring your statement is seconded

quite possible. I was going back and forth between FWH and traditional hopping.

Kai
Title: Re: Carboy Oxidation - sure doesn't take long!
Post by: babalu87 on January 10, 2010, 01:36:01 AM

If that was one of the Pilsners you gave me last Spring your statement is seconded

quite possible. I was going back and forth between FWH and traditional hopping.

Kai

It was Pils #74 Kai.
I liked it a little better than #78 Pils

I sent you an e-mail this AM @ brau kaiser
Title: Re: Carboy Oxidation - sure doesn't take long!
Post by: Kaiser on January 10, 2010, 07:12:29 PM
It was Pils #74 Kai.
I liked it a little better than #78 Pils

74 was FWHed while 78 has a more classical Pilsner hopping. But both were brewed a few weeks apart. When I checked my notes I didn't mention anything about harsh bitterness for any of them.

I guess your mileage does very and there are likely other factors that may play a role. I like FWH b/c I don't have to worry about additional hop additions later and can leave the boil alone for most of the time.

Kai
Title: Re: Carboy Oxidation - sure doesn't take long!
Post by: tom on January 11, 2010, 12:05:09 AM
Assuming I did the math / science right...  and it's been a while so I could be wrong.

If your secondary carboy is filled with 4.75 gal of beer and .25 gal of CO2 then you will lose 10.35 teaspoons of CO2 volume in the headspace and 3 teaspoons of beer volume (neglecting alcohol content and assuming a drop from 60F to 32F).

This is just over a quarter of a cup.  Is that enough air going in to oxidize the beer (assuming your airlock doesn't dry out completely as major's did).

What else am I missing in my logic?  More gas is dissovled at lower temps?  Do you take the whole carboy volume into consideration for CO2 and not just the headspace?
Once the airlock is dry, air will diffuse into the carboy forever.
Title: Re: Carboy Oxidation - sure doesn't take long!
Post by: seajellie on January 11, 2010, 04:13:41 AM
Kai, what hops did you use for FWH in that pilsner that turned out so well?

Me thinks this is like dry hopping, it works better with some hop varieties than others. And as you said, there are likely a number of factors in play. I'd suggest looking at water chemistry, hummulene/myrcene/etc. content of the hops, and of course malts used (for balance). The three times I used FWH and it turned out nice, was with 2% spalt. Four times I did FWH and the results were not good at all; the hops were hersbrucker and tettnang in those cases, at 4.5+%. It would be nice to know more about this as when it works, it's great. At this point however, I'll probably only try it with low aa% because I don't like that lingering bitterness and it's not worth risking a beer.

This subject is probably worthy of a phd!
Title: Re: Carboy Oxidation - sure doesn't take long!
Post by: blatz on January 11, 2010, 02:23:22 PM
very good point seajellie - your examples are similar to the experience I've had with FWH - with Spalt, its been nice, but in the pilsner I made recently (mentioned a few posts back in this thread) it was actually Hallertau and Tettnang as the FWH, which isn't terrible, but I don't really like it and prefer the traditional kettle additions.

Title: Re: Carboy Oxidation - sure doesn't take long!
Post by: Kaiser on January 11, 2010, 02:36:22 PM
The beers that I sent to Jeff were all hopped with Hallertau Tradition. I first noticed that FWHing gives an authentic Pilsner hop flavor and profile when I brewed a Helles and used FWH. My think was that if it doesn't work I'll get a Helles and when it works I'll have a Pilsner. Here is a blog entry on this : Helles That Became A Pilsner (http://braukaiser.com/lifetype2/index.php?op=ViewArticle&articleId=17&blogId=1).

I figure that, with most brewing techniques, you can neither discredit it or claim that it is the best and only way to brew. We have little understanding what actually happens during FWH although there are some compelling theories out there. The only thing we know is that it can work.

Kai
Title: Re: Carboy Oxidation - sure doesn't take long!
Post by: denny on January 11, 2010, 04:16:15 PM
Hmmmmm.....I've FWh with over a dozen different varieties of hops and so far I haven't found one I didn't like!
Title: Re: Carboy Oxidation - sure doesn't take long!
Post by: Thirsty_Monk on January 11, 2010, 05:42:49 PM
I FWH with Saaz and Hallertau.
I did not like both of them even thou Hallertau was not as pronounced.
I based my FWH on Brewing Techniques "The History and Brewing Methods of Pilsner Urquell"
http://www.brewingtechniques.com/library/backissues/issue5.3/urquell.html

Quote
The hops are grown in the nearby Zatec region of Bohemia. Hops are initially added into the sweet wort before it reaches a boil (first wort hopping); more hops are added about 80 minutes before the end of the boil, and the final addition is added about 25 minutes before the end of the boil. (Pilsner Urquell is not dry-hopped.) Alpha-acid levels in the Saaz hops during the past five years have averaged about 3.8%

I also think that 80 min boil gives it vegetile notes.
I have to say I got very close hop aroma.
I wonder if they do not "age" the hops to use these techniques.
Title: Re: Carboy Oxidation - sure doesn't take long!
Post by: uthristy on January 12, 2010, 08:58:45 PM
on another HB forum>
 I  was told that " (Palmer, or Chris Colby of BYO) said that in order to truly provide enough O2 to oxydize our beers it would take pumping and entire one of our red oxygen bottle/airstones into our beer AFTER fermentation is complete." ::)

and that I'm obsessing because of wanting to purge my carboys & `burp the kegs with CO2.



The wide range of info one comes across on the internet.

Title: Re: Carboy Oxidation - sure doesn't take long!
Post by: Kaiser on January 12, 2010, 09:03:45 PM
on another HB forum>
 I  was told that " (Palmer, or Chris Colby of BYO) said that in order to truly provide enough O2 to oxydize our beers it would take pumping and entire one of our red oxygen bottle/airstones into our beer AFTER fermentation is complete." ::)

That must have been taken out of context or the originator of this statement has a different idea of what oxidation is. I have purposefully oxidized beer and didn’t need a full O2 tank.

Kai
Title: Re: Carboy Oxidation - sure doesn't take long!
Post by: dean on January 12, 2010, 09:07:14 PM
Assuming I did the math / science right...  and it's been a while so I could be wrong.

If your secondary carboy is filled with 4.75 gal of beer and .25 gal of CO2 then you will lose 10.35 teaspoons of CO2 volume in the headspace and 3 teaspoons of beer volume (neglecting alcohol content and assuming a drop from 60F to 32F).

This is just over a quarter of a cup.  Is that enough air going in to oxidize the beer (assuming your airlock doesn't dry out completely as major's did).

What else am I missing in my logic?  More gas is dissovled at lower temps?  Do you take the whole carboy volume into consideration for CO2 and not just the headspace?

I don't get it either... regardless, the CO2 is heavier (creating a blanket) than the small amount of air that could possibly have entered the carboy so the beer should never have been oxidized in the first place.   ???
Title: Re: Carboy Oxidation - sure doesn't take long!
Post by: majorvices on January 12, 2010, 09:12:52 PM
Assuming I did the math / science right...  and it's been a while so I could be wrong.

If your secondary carboy is filled with 4.75 gal of beer and .25 gal of CO2 then you will lose 10.35 teaspoons of CO2 volume in the headspace and 3 teaspoons of beer volume (neglecting alcohol content and assuming a drop from 60F to 32F).

This is just over a quarter of a cup.  Is that enough air going in to oxidize the beer (assuming your airlock doesn't dry out completely as major's did).

What else am I missing in my logic?  More gas is dissovled at lower temps?  Do you take the whole carboy volume into consideration for CO2 and not just the headspace?

I don't get it either... regardless, the CO2 is heavier (creating a blanket) than the small amount of air that could possibly have entered the carboy so the beer should never have been oxidized in the first place.   ???

That's a myth. Co2 and o2 mix. There is not a co2 blanket once the beer stops producing co2 if there is a way for 02 to get in. Otherwise you wouldn't be able to breath on the earth since co2 would blanket the entire surface right about head level.  ;)
Title: Re: Carboy Oxidation - sure doesn't take long!
Post by: dean on January 12, 2010, 09:21:29 PM
Oh I'm sure it mixes but at such a small quantity its hardly traceable without very sophisticated equipment.  Just fess up major, you splashed it didn't ya?   :D
Title: Re: Carboy Oxidation - sure doesn't take long!
Post by: brewboy on January 12, 2010, 10:21:37 PM
They'll mix, but CO2 is still heavier and should do a good job of protecting your beer.
Title: Re: Carboy Oxidation - sure doesn't take long!
Post by: ndcube on January 12, 2010, 11:01:57 PM
I know once I take the lid off of a fermenting bucket and do a flame test the flame goes out.  Shortly after the flame stays lit.

I would imagine any amount of O2 that isn't absorbed by sulfur compounds oxidizes beer but it's a matter of what is detectable.

One of my first batches I tried a barleywine.  The yeast got stuck (or so I thought) so I gave it a blast of pure O2 for 60 seconds.  Definetely enough to oxidize.  I won't forget that taste.
Title: Re: Carboy Oxidation - sure doesn't take long!
Post by: ndcube on January 13, 2010, 11:55:41 AM
Also, Seems like there is already a bunch of CO2 dissolved in brews after fermentation.  I just degassed a wine and it took several minutes of whipping it until I could hold a flame over the neck of the carboy.

...I'm not about to degas a beer so don't ask.

I'll have to watch my airlock more closely the next time I cold condition.  I don't recall any negative pressure during the crash with zero headspace but I wasn't paying attention.  It's my guess that the negative pressure comes with headspace.
Title: Re: Carboy Oxidation - sure doesn't take long!
Post by: majorvices on January 13, 2010, 01:00:27 PM
Guys, the beer was in the chest freezer for probably 2-4 weeks without water in the airlock. The beer was completely flat when I tranferred it - no dissolved Co2. I don't know what else I can say. If beer is that stable that it can go weeks with no protection from the outside air then there is simply no reason to use airlocks at all!

Sure, a few days, I am positive it wouold be no problem. I have had kegs that were not carbbed lose pressure and I never had an issue. But, for heaven's sake I have been brewing this recipe (or a close proximity thereof) for 15 years or so and I think I can taste oxidation when I run across it. Lordy mercy - you guys need to leave your beer in the primary for an extra 4 weeks (probably 6 total) without an airlock it you feel so damn confindent it is not an issue.  ::)
Title: Re: Carboy Oxidation - sure doesn't take long!
Post by: ndcube on January 13, 2010, 01:25:10 PM
I wasn't saying you didn't have an airlock issue major.  I trust you know how your recipe is supposed to taste.

I have just never crashed cooled beers before December and want to figure out for myself whether or not a secondary carboy with a full airlock and no headspace will suck in air and oxidize the beer.

Sorry if this was off topic.
Title: Re: Carboy Oxidation - sure doesn't take long!
Post by: majorvices on January 13, 2010, 02:21:35 PM
No worries, re-reading, that post came off sounding grumpier than my intention. First cup of coffee and all.  ;) I'm all for a thread evolving in any direction as long as it is helpful.
Title: Re: Carboy Oxidation - sure doesn't take long!
Post by: Kaiser on January 13, 2010, 03:19:03 PM
I remember discussing a similar subject before on another board. The main topic was if the CO2 content that should be considered for bottling needs to be calculated with the temp at which the beer stopped fermenting or the current beer temp. My argument was that cooling the beer will allow more CO2 to be absorbed which will come from the headspace. Another user mentioned that be barely sees the airlock water level move when he crashes his beers.

Aside from that I still think that the beer will suck in CO2 from the head space if it is done fermenting and cooled considerably. There is more room for CO2 in the beer at colder temps and it needs to be filled. I don’t know how long it would take though but am concerned that a considerable amount of air would be pulled in.

So I ran a quick calculation of the problem. I assume that there are 20 l of beer with a 2 l head space. It is sitting at 20 C (68 F) and is at equilibrium with the head space CO2. That headspace CO2 is at atmospheric pressure (~100 kPa). No more CO2 is produced by the fermentation. Now the beer is chilled to 0 C (32 F). Since the beer can absorb more CO2 it will do that. As I mentioned earlier it will pull in air and dilute the CO2 which lowers the CO2 head pressure. Once that CO2 head pressure has fallen to about 55 kPa, which corresponds to a head space CO2 content of 55%, the 0 C beer CO2 content will be at equilibrium with the head space again. As a result about 65% of 2 l = 1.3 l air must have been pulled in through the airlock.

2 l head space might be a bit generous for a secondary. If you have only a pint (500 ml) you will pull in only 325 ml ( ~0.3 qt) of air. I’m not sure if that is enough to cause considerable oxidation since a lot of brewers are doing exactly that w/o apparent stability problems. If I go a bit further and make the assumption that the 20 C beer may be oversaturated with CO2 (i.e. holds more CO2 that what it should be able to hold at its pressure and temp) it would have to hold almost twice as much CO2 in order to prevent air from being sucked into the head space while and after chilling to 0 F.

If the beer is only chilled to 10 C (50F) only 25% of the head space will be replaced with air.

These calculations neglect the temperature dependent contraction of the head space volume which only makes the problem worse.

In Keith’s case the airlock ran dry which allowed much more air to diffuse into the head space.

For those who cold crash beer in a secondary, do you see negative pressure on the airlock to the extend that air is pulled in? Or do you see CO2 escape from the beer. The latter can be evident by the formation of bubbles on the surface.

Kai
Title: Re: Carboy Oxidation - sure doesn't take long!
Post by: bluesman on January 13, 2010, 05:56:06 PM
I recently made a Boston Lager clone. I brewed the beer and chilled it down to about 60F then transfered it into a  (2) 7.5 gallon buckets which were then transferred into my chest freezer controlled by a  Johnson controller set at 50F.

I leave the airlocks off because if I don't, the cooling of the air in the headspace will cause the air to contract which will in turn suck the liquid out of the airlocks and into the beer. So it's a tradeoff between sucking the liquid from the airlocks into the beer or sucking more O2 into the headspace which will then oxidize the beer.

Once the beer gets down to pitching temp, I install the airlocks. That usually takes about 4-6 hours or so in my chest freezer.

Title: Re: Carboy Oxidation - sure doesn't take long!
Post by: tygo on January 13, 2010, 05:59:04 PM
In that case though it shouldn't really matter since that was your primary fermentation though.  You wouldn't need to worry about oxidizing the beer at that point.  The tricky part seems to me dropping the beer to lagering temperatures from fermentation temps if you're using a carboy with an airlock as opposed to a keg under pressure.
Title: Re: Carboy Oxidation - sure doesn't take long!
Post by: bluesman on January 13, 2010, 06:01:38 PM
In that case though it shouldn't really matter since that was your primary fermentation though.  You wouldn't need to worry about oxidizing the beer at that point.  The tricky part seems to me dropping the beer to lagering temperatures from fermentation temps if you're using a carboy with an airlock as opposed to a keg under pressure.

Yes, assuming that the yeast will chew up all of the available O2 during the fermentation process. I typically lager in a keg with the exception of a Dopplebock or the like which then presents the same issue.

The best way to avoid this issue is to secondary and/or lager in the keg.
Title: Re: Carboy Oxidation - sure doesn't take long!
Post by: Kaiser on January 13, 2010, 06:42:03 PM
If you want to get serious about lagers, I recommend working with kegs. I’ve started using them to cold condition my lagers way before I even had a keg-o-rator.

Kai

Title: Re: Carboy Oxidation - sure doesn't take long!
Post by: blatz on January 13, 2010, 07:23:15 PM
If you want to get serious about lagers, I recommend working with kegs.

+1 - problem solved.
Title: Re: Carboy Oxidation - sure doesn't take long!
Post by: majorvices on January 13, 2010, 10:14:36 PM
+2 - in fact, if you really want to get serious about beer I recommend kegs.  ;)
Title: Re: Carboy Oxidation - sure doesn't take long!
Post by: ndcube on January 13, 2010, 11:02:08 PM
+2 - in fact, if you really want to get serious about beer I recommend kegs.  ;)

Kegs are next on my list.  For now I'm using carboys.  If I ever need another carboy the money will most likely be spent on a keg instead.
Title: Re: Carboy Oxidation - sure doesn't take long!
Post by: blatz on January 14, 2010, 12:13:53 AM
Kegs are next on my list.  For now I'm using carboys.  If I ever need another carboy the money will most likely be spent on a keg instead.

don't know if you got an extra benjamin burning a hole, but NB has/had a pretty good sale going on - 4 for $115 I think?
Title: Re: Carboy Oxidation - sure doesn't take long!
Post by: troy4500 on January 14, 2010, 12:34:32 AM

For those who cold crash beer in a secondary, do you see negative pressure on the airlock to the extend that air is pulled in?

Kai


I see this everytime I cold crash.  wheter in the primary or secondary carboy.  This is something I have alway wondered about.  I have always read about people opting to cold crash in the primary then keg or bottle to avoid O2, but I always have a negitave pressure occur and have wondered how that is any different.  That being said, I secondary alot of my beers and have never had an oxidation issue, though I am now doing secondary and cold crashing in the keg.
Title: Re: Carboy Oxidation - sure doesn't take long!
Post by: Thirsty_Monk on January 14, 2010, 03:02:25 AM
Kegs are next on my list.  For now I'm using carboys.  If I ever need another carboy the money will most likely be spent on a keg instead.

don't know if you got an extra benjamin burning a hole, but NB has/had a pretty good sale going on - 4 for $115 I think?
I have a guy in club who is selling them for $10 a piece.
You just have to drive to his farm. :D
They are not recondition and he has like 300 of them (at least that is the claim).
Title: Re: Carboy Oxidation - sure doesn't take long!
Post by: ndcube on January 14, 2010, 11:29:44 AM
Kegs are next on my list.  For now I'm using carboys.  If I ever need another carboy the money will most likely be spent on a keg instead.

don't know if you got an extra benjamin burning a hole, but NB has/had a pretty good sale going on - 4 for $115 I think?

Looks like it's part of their $8 shipping too.  I've seen them cheaper on other sites but shipping is like $40.  I just put in an NB order or I may have done that.  'Course then one needs all the accesories too...  then I'd want to build a kegerator (which isn't allowed in the kitcehn for some reason)... buy even more kegs...  think I'll stick with what I've got for a few more months.
Title: Re: Carboy Oxidation - sure doesn't take long!
Post by: dean on January 14, 2010, 02:40:32 PM
I've got ten cornies and have yet to have them all filled at the same time, so using them as secondaries sounds like a really good idea.  Would I need to cut the dip tube, how much sediment typically settles out doing a secondary?

Keith... you should know some of us just like fun with ya when we get the opportunity.   ;)
Title: Re: Carboy Oxidation - sure doesn't take long!
Post by: Thirsty_Monk on January 14, 2010, 03:39:49 PM
I've got ten cornies and have yet to have them all filled at the same time, so using them as secondaries sounds like a really good idea.  Would I need to cut the dip tube, how much sediment typically settles out doing a secondary?

Keith... you should know some of us just like fun with ya when we get the opportunity.   ;)
I have two kegs with dip tub cut.
If you do that you can cut 1/2 inch off.
I use them as a clear tanks.
I rack beer from fermenter to these kegs.
Cold condition it for 2 weeks and I transfer it to serving keg.
IMO It is worth the effort.
Title: Re: Carboy Oxidation - sure doesn't take long!
Post by: bluesman on January 14, 2010, 03:47:51 PM
This is the thread that just keeps going...and going...and going. I love it. ;D

Title: Re: Carboy Oxidation - sure doesn't take long!
Post by: denny on January 14, 2010, 05:53:19 PM
I've got ten cornies and have yet to have them all filled at the same time, so using them as secondaries sounds like a really good idea.  Would I need to cut the dip tube, how much sediment typically settles out doing a secondary?

I don't bother cutting the dip tube.  I just blow out the sediment in the bottom before either serving or xferring to a serving keg.
Title: Re: Carboy Oxidation - sure doesn't take long!
Post by: Kaiser on January 14, 2010, 06:00:22 PM
I cut my dip tubes quite generously. So much that I'm leaving about a pint behind when. Tranfer to a serving keg. The reasoning is that I want to minimize the sediment that gets into the serving keg. In particular the last pint will be cloudy if you don't cut the dip tube since the beer level has reached the domed bottom and starts washing sediments off its slope. But if you are serving from the secondary you may not care.

Kai
Title: Re: Carboy Oxidation - sure doesn't take long!
Post by: majorvices on January 14, 2010, 06:16:12 PM
Count me in a as a dip tube cutter as well (I have 4 or 5 cornies with shortened tubes used for bright tanks). Though, on beers I am not particularly concerned about clarity with I don't bother using a bright tank (or secondary for that matter) and just blow the first couple of pints as cloudy, Of course, I drink 'em. Its good for you.  ;)
Title: Re: Carboy Oxidation - sure doesn't take long!
Post by: dean on January 14, 2010, 06:22:45 PM
Well, maybe I'll just have to try using my cornies as fermenters then.  I guess I can see where cutting the dip tube might be nice for saving yeast if I used as a primary fermentation.  But sometimes I get a lot of sediment so that worries me.  Sorry for getting the thread off track.   :-[   :-*   :D
Title: Re: Carboy Oxidation - sure doesn't take long!
Post by: blatz on January 14, 2010, 06:26:00 PM
I don't bother cutting the dip tube.  I just blow out the sediment in the bottom before either serving or xferring to a serving keg.

+1  here
Title: Re: Carboy Oxidation - sure doesn't take long!
Post by: dean on January 14, 2010, 06:38:50 PM
After reading the posts and seeing as I have 10 cornies, I'm gonna stick my neck out and cut two dip tubes and use those cornies for primary and use two uncut for secondary fermenters.  I'll keep my carboys handy though so if I don't like it I can fall back on them.   :)
Title: Re: Carboy Oxidation - sure doesn't take long!
Post by: ndcube on January 26, 2010, 12:16:31 AM
I transferred my Kolsch to a secondary better bottle yesterday morning to my 35F chest freezer.  It's been about 36 hours and there hasn't been any airlock activity other then some positive pressure.  There isn't any headspace and it started at 65F.
Title: Re: Carboy Oxidation - sure doesn't take long!
Post by: Thirsty_Monk on January 26, 2010, 12:59:07 AM
After reading the posts and seeing as I have 10 cornies, I'm gonna stick my neck out and cut two dip tubes and use those cornies for primary and use two uncut for secondary fermenters.  I'll keep my carboys handy though so if I don't like it I can fall back on them.   :)

You can use tubing cutter for it.
I would cut only 1/2 inch to begin with.
I have two kegs with dip tube cut off and I use them as clearing tank (I rack beer from fermenter here first).
I see you are going to use it in different manner.
Title: Re: Carboy Oxidation - sure doesn't take long!
Post by: aluminumpark on May 13, 2010, 01:38:42 PM
This is late, but I just had a lightbulb moment!!!


next time I do this I'm going to have a hose coming out of my airlock (like a skinny blowoff tube) thats connected to some kind of variable volume bag. The bag will be filled with CO2, and allow co2 exchange in and out of the fermenter. right now for a bag i'm thinking that a wine bladder might work well. also those collapsable cube containers that some of the online HB store sells might work.