Cold crashing problems and questions!!!

[day_trippr]

Your implication is that ingress through the airlock is the prime factor?

Actually, you can't find any specific modality implied or expressed...

Cheers!

[edit] But as you did kinda ask...I expect the contribution of post-fermentation air ingress via air-lock is a minor player compared to the lead role: bad racking technique, which would include "un-purged receiver" as the major character defect that makes every other potential process flaw (eg: splashing) even worse...

 

[Horseshoot]

If there's any O2 in the headspace, the O2 will evenly mix with the CO2. It doesn't matter that CO2 is more dense than what gets sucked in. The molecules bounce around and all of the gasses will evenly mix. You then have O2 in contact with the beer. It sounds like the OP is trying to eliminate all O2 exposure. An S shaped airlock isn't going to do what he wants.

CO2 is denser that O2. It will settle lower than O2. Every time. So, it will crete a blanket of C02, over the beer.

Mike

 

[day_trippr]

CO2 is denser that O2. It will settle lower than O2. Every time. So, it will crete a blanket of C02, over the beer.

Mike

No, it won't. Never, ever, ever.
If it did, neither of us would be here right now.

And here's why..

Cheers!

 

[Horseshoot]

Co2 "blanket" is always brought up in these discussions. There is no Co2 blanket. Mixture by enthalpy will result in the Co2 diffusing into the air very quickly. Even without any chemistry knowledge....if Co2 didn't diffuse in the air why doesn't our breath cause a Co2 "blanket" to form in spaces with large amounts of people?[/QUOTE]

C02 is heavier. It settles. Into the low spaces. In certain open heart surgeries, C02 is introduced into the chest in order to prevent air from entering open vessels. And it works. The blanket concept is real.

Mike

 

[day_trippr]

No, it doesn't. What you are describing is a procedure where there is a constant flow of CO2 flooding the area and physically displacing other gases. It's a temporary condition that ceases to exist once the gas flow is shut off.

And it has zero relationship to the static condition that exists in a fermenter or keg...

Cheers!

 

[Horseshoot]

I don't really know for sure, but my gut tells me that there are just as many crazy oxidation guys out there as there is crazy sanitation guy. Just nobody has found crazy CO2 purge oxidation guy's video yet.ipe:

^ This...

Mike

 

[Horseshoot]

Doesn't matter the hobby, there is always going to be some contingent having OCD.

Brewing is moderate from what I've seen so far. Wanna see some OCD mofos, get into audio (which, BTW, is another of my bigger hobbies).

^ HAHAHA!! And this! My best bud is an audio guy!

Mike

 

[ChelisHubby]

I just take off the bubbler and put on foil when I cold crash as the tempature and the air in the fridge are a hard place for a infection to breed or live! 120 dllrs for a batch would be painful!

 

[Horseshoot]

No, it won't. Never, ever, ever.
If it did, neither of us would be here right now.

And here's why..

Cheers!

I worked 12 years in an environment (open heart surgery) that proves it does create a blanket.

Mike

 

[Horseshoot]

No, it doesn't. What you are describing is a procedure where there is a constant flow of CO2 flooding the area and physically displacing other gases. It's a temporary condition that ceases to exist once the gas flow is shut off.

And it has zero relationship to the static condition that exists in a fermenter or keg...

Cheers!

During fermentation there isn;t a constant flow of C02?

Mike

 

[jddevinn]

Co2 "blanket" is always brought up in these discussions. There is no Co2 blanket. Mixture by enthalpy will result in the Co2 diffusing into the air very quickly. Even without any chemistry knowledge....if Co2 didn't diffuse in the air why doesn't our breath cause a Co2 "blanket" to form in spaces with large amounts of people?

C02 is heavier. It settles. Into the low spaces. In certain open heart surgeries, C02 is introduced into the chest in order to prevent air from entering open vessels. And it works. The blanket concept is real.

Mike[/QUOTE]

No it doesn't. This is basic physics. I'm not "postulating" possibilities here. I have physics and mechanical engineering degrees and consider gas mixtures every day for work, I know what I am talking about. If you lay on the ground do you die because you are in a CO2 blanket and can't breath?

Constant supply of a gas during surgery or during welding is different then what we are talking about. If higher molecular weight gasses formed a blanket a constant supply would be unnecessary.

 

[day_trippr]

You're falling behind - PKU

And your conflating two different physical paradigms still doesn't apply...

Cheers!

 

[bob1852]

Your implication is that ingress through the airlock is the prime factor?

Betterbottle's website had some cool data on how much oxygen actually makes it through the plastic in a airlock and bung, not just through the liquid...

http://www.better-bottle.com/technical.html

(Click on the permeability tab)

 

[jddevinn]

During fermentation there isn;t a constant flow of C02?

Mike

I alluded to this earlier in the thread. Do I need to do the math to show that on the level we are talking about the CO2 produced is way way less than the dissipation rate of an open system? Even if the system is not open the ppm concentration of 02 required for oxidation effects (especially in lighter beer) is low enough that it doesn't matter?

 

[iijakii]

I use a low pressure propane regulator which puts 0.4 psi on the fermenter during crashing. Nothing goes in but CO2.

Have a link?

 

[bob1852]

During fermentation there isn;t a constant flow of C02?

Mike

That's not a CO2 "blanket", it's a function of positive pressure.

Once fermentation is done, there's no longer a flow of CO2, and any O2 that enters by whatever means will mix with whatever CO2 is left.

 

[day_trippr]

Have a link?

Awesome bling aside, you can pick up a .5 psi gas regulator at any big box hardware store in the gas grill parts aisle...

Cheers!

 

[iijakii]

Awesome bling aside, you can pick up a .5 psi gas regulator at any big box hardware store in the gas grill parts aisle...

Cheers!

Thanks, I'll do that. I know when I was ebay searching awhile back I kept finding propane ones but didnt stop to think about it's all the same. Ill pick one up and start cold crashing in the fermenter again one of these days. I dont keep the keezer too cold so it doesnt have the same effect cold crashing in the keg.

 

[kevink]

Have a link?

It works great. You will love it. It even works when dumping trub if you have a conical. Instead of removing the airlock or blowoff and letting air in when you dump, you use this and the volume lost is replaced with CO2 instead of air.

http://www.amazon.com/gp/product/B00KTS20JM?psc=1&redirect=true&ref_=od_aui_detailpages01

 

[kevink]

Awesome bling aside, you can pick up a .5 psi gas regulator at any big box hardware store in the gas grill parts aisle...

Cheers!

I looked at those stores, but all of the regulators were more expensive and had permanently attached propane tank fittings and/or hoses which wouldn't have worked. The one I linked to has standard female NPT threads on the inlet and outlet which is what you want. Plus, the ones at my local stores were cheap quality, uncoated, and can't be disassembled.

 

[Horseshoot]

That's not a CO2 "blanket", it's a function of positive pressure.

Once fermentation is done, there's no longer a flow of CO2, and any O2 that enters by whatever means will mix with whatever CO2 is left.

I get your point. And I defer to your expertise. Blanket is probably the wrong word. But my point is (and I am actually asking this as a question, because you would know better than I) if one compares the amount of C02 above the beer to the small amount entering via the airlock, during a cold crash; do you think it would be enough to seriously cause any issues with the beer?
I have never used any extraordinary precautions while racking my beers (aside form the common sense ones such as purging the keg prior to racking, and the like). And I have stored several beers for many years (usually by accident) yet I have never detected any evidence of oxygenation problems. Is this a common problem? Or is it an area where we are taking potential problem, and blowing it way out of proportion? I, like most of us, want to make the best possible beers that I can. But, if I were a newbie, I would feel overwhelmed if I thought I had to install pressure regulators or other complex systems to make great beer. I get the idea of being cautious to avoid oxygenation. But, I do think we sometimes overthink these things.
Anybody out there ever have a beer show signs of oxygenation? And if so, were you able to pinpoint the reason?

Mike

 

[jddevinn]

I get your point. And I defer to your expertise. Blanket is probably the wrong word. But my point is (and I am actually asking this as a question, because you would know better than I) if one compares the amount of C02 above the beer to the small amount entering via the airlock, during a cold crash; do you think it would be enough to seriously cause any issues with the beer?
I have never used any extraordinary precautions while racking my beers (aside form the common sense ones such as purging the keg prior to racking, and the like). And I have stored several beers for many years (usually by accident) yet I have never detected any evidence of oxygenation problems. Is this a common problem? Or is it an area where we are taking potential problem, and blowing it way out of proportion? I, like most of us, want to make the best possible beers that I can. But, if I were a newbie, I would feel overwhelmed if I thought I had to install pressure regulators or other complex systems to make great beer. I get the idea of being cautious to avoid oxygenation. But, I do think we sometimes overthink these things.
Anybody out there ever have a beer show signs of oxygenation? And if so, were you able to pinpoint the reason?

Mike

Roughly 1ml of air in a 300ml bottle will give an oxygen content of 1ppm, which is probably enough to oxidize all the reductones present in a light lager beer. [Brewing Science and practice] converting and expanding to batch size, this is equivalent to ~4 cubic inches of (standard pressure) air for a 5 gallon batch.

I can tell when the beer that I make is oxidized, normally after about a month or so in the keg.

 

[Horseshoot]

Roughly 1ml of air in a 300ml bottle will give an oxygen content of 1ppm, which is probably enough to oxidize all the reductones present in a light lager beer. [Brewing Science and practice] converting and expanding to batch size, this is equivalent to ~4 cubic inches of (standard pressure) air for a 5 gallon batch.

I can tell when the beer that I make is oxidized, normally after about a month or so in the keg.

Much more than I would have expected. Maybe I don't realize mine are getting oxygenated? I haven't detected it.

Mike

 

[TAK]

I just put a real blanket in my bucket. Problem solved.

 

[masonsjax]

My thoughts on why the "blanket" of CO2 phrase gets tossed about so often:
Heavy gasses behave as a fluid until they have sufficient time to homogenize. The heavier the gas, the slower this happens. This is why many auto shops opt for lifts vs pits and why the govt codes require forced ventilation in service pits where explosive gasses can pool. Same for when volcanic activity releases a large amount of gasses that then flow for a long time before diffusing. Once mixed, stratification does not occur.

How much time does it take for an unagitated small volume of nearly pure CO2 to completely dissipate when opened to the atmosphere? I certainly don't know, but my guess would be that a quick cold crash wouldn't be long enough to cause a serious problem.

 

[day_trippr]

[...]How much time does it take for an unagitated small volume of nearly pure CO2 to completely dissipate when opened to the atmosphere? I certainly don't know, but my guess would be that a quick cold crash wouldn't be long enough to cause a serious problem.

Not that it matters that much, but a "quick cold crash" would be how many days?

Most of the air is going to be introduced in the first handful of hours or so as the gases in the head space rapidly cool. I expect that the homogenization process is constant and rapid and would have no problem keeping up with the ingress of air through an air lock.

I'm talking minutes, here...

[edit] So I'd take the position that within a day the head space in the open, crashing fermenter is going to have a significant amount of O2 content.
And as the beer cools it's easier to dissolve gases therein, which goes to the "time" thing.
The unanswered question has always been "Ok, so is this going to actually hurt?"
And to be honest, I still don't know, so I avoid the whole issue with CO2 top pressure during crashes and worry about other things...

Cheers!

 

[Pkrd]

Its just a small step from here to CO2 blanket...
[ame]https://www.youtube.com/watch?v=DzLX96VWTkc[/ame]

 

[day_trippr]

lol!

Molar mass at STP:
N2 = 14.007 g/mol
Air = ~29 g/mol
CO2 = 44.01 g/mol
SF6 = 146.06 g/mol

So, a pretty big step, actually

Cheers!

 

[iijakii]

You past few posters must have missed this post - https://www.homebrewtalk.com/showpost.php?p=7422251&postcount=43

 

[Pkrd]

You past few posters must have missed this post - https://www.homebrewtalk.com/showpost.php?p=7422251&postcount=43

I really should have put a in there.
I was just pointing out that the concept of a gas blanket wasn't completely crazy.