cold crash airlock suck

[stompbox]

How do you cold crash without getting the airlock liquid sucked into the beer? I have only tried cold crashing once and this was an issue.

I have 3 batches I want to cold crash this week and looking for solutions.

 

[seigex]

use a sanitized rubber stopper without a hole in it

 

[julioardz]

I mostly ferment in a bucket and leave the lid loosely placed on top when cold crashing. As a matter of fact, I usually leave the lid loosely placed on top throughout the entire fermentation. In a carboy, I would just pull the stopper and wrap a bit of foil over the opening, maybe even use a rubber band to hold it in place. If you worry about infections you can spray the foil with some sanitizer if you like.

 

[dzlater]

Dump the liquid out of the airlock, and replace with a cotton ball to act as a filter.

 

[grathan]

Drop the temp in increments. Maybe 10 degrees at a time.

 

[jperry]

How do you cold crash without getting the airlock liquid sucked into the beer? I have only tried cold crashing once and this was an issue.

I have 3 batches I want to cold crash this week and looking for solutions.

If using a 3-piece airlock, Use just enough starsan, to float the airlock. By using less liquid in the airlock, there will not be enough starsan, to able to be sucked back, into a fermenter. I do this all the time, when I cold crash.

 

[BrewingGunner]

Replace the 3 piece airlock with an S type bubbler during cold crashing.

 

[LBussy]

A three piece, filled with just enough (cheap) vodka to float the cup will not suck any back. If it does it's just vodka.

use a sanitized rubber stopper without a hole in it

... don't follow that advice. If you get it sealed well enough to make it matter that you are using a stopper, it will suck into the carboy. Most likely however it will just put enough suction on it to pull air around the edges. At least with an airlock you bubble it through vodka, making a passing attempt at sanitizing.

 

[Jlaw3000]

As everyone has said, use S shapes. All I use now for this reason.

 

[seigex]

A three piece, filled with just enough (cheap) vodka to float the cup will not suck any back. If it does it's just vodka.



... don't follow that advice. If you get it sealed well enough to make it matter that you are using a stopper, it will suck into the carboy. Most likely however it will just put enough suction on it to pull air around the edges. At least with an airlock you bubble it through vodka, making a passing attempt at sanitizing.

If you use a solid stopper it will seal and create a vacuum within the carboy... if you use vodka or starsan in an airlock, eventually it will suck it all through you will still be sucking air through once it runs out of vodka/starsan to suck through ... not sure why he shouldn't follow my advice, this is what I've been doing for more than 8 years and haven't had an issue.

I'm not the only one with this suggestion:

https://www.homebrewtalk.com/f163/cold-crash-air-lock-sucking-200395/

Can you pull out the airlock and replace it with a solid bung? The reason it's sucking in is because of the temperature dropping inside the fermenter and pulling a vacuum. If you take out the airlock and replace it with a solid bung (or even some sanitized foil), that will be a quick and easy fix.

 

[LBussy]

If you use a solid stopper it will seal and create a vacuum within the carboy... if you use vodka or starsan in an airlock, eventually it will suck it all through you will still be sucking air through once it runs out of vodka/starsan to suck through ... not sure why he shouldn't follow my advice, this is what I've been doing for more than 8 years and haven't had an issue.

I've only been doing it since '91 or so. Neither the S lock nor the 3-piece will suck back through if they are filled correctly. If they are not they will suck some through (which is why I recommend vodka) and then stop.

I have experimented with using solid stoppers in empty carboys (which creates a larger vacuum because of the volume of air) and with new stoppers I can get them to seal ~75% of the time and of those they suck in about 50% of the time. With older stoppers where I assume the rubber is hardened, nearly 90% of them fail and pass air. I share this because most people are not obsessive-compulsive enough to try all this themselves.

Now *if* you can get a good seal, and *if* you keep from pulling the stopper in, then it's a superior method IMHO because it will also de-gas the beer at the same time. This is not often done by brewers but our wine-making brethren know it will definitely help a liquid clear faster. For this I have used the orange rubber caps, the plugs that come with them, and a hose clamp around the top. The more headspace is in the carboy the greater the effect. If there is liquid to the top you will likely not develop any vacuum.

So, apologies for what sounded like an extremely dismissive treatment of your advice. It was pre-coffee and not meant to be offensive. I'm just going by my experience. I feel for most people that simply leaving a perfectly good airlock on there, avoiding the opportunity to infect the beer by switching stoppers, and using something which will not have any negative effects if suckled in, will be the better solution.

Incidentally, I tried this with a 6 gallon Better Bottle and their stopper/airlock setup. 5 gallons of product in a 6 gallon BB will leave enough head space to create a profound vacuum that will start to collapse the bottle.

ETA (since you edited after I began to reply):

I'm not the only one with this suggestion:

Simply because you can find other people doing the same thing does not necessarily mean it is correct or better.

A refrigerator is a horribly dirty place, full of all sorts of spoilage microorganisms. My method assumes a large possibility of not forming a good seal. That being the case I do not want to create a channel with which gravity and in-rushing air will be utilized by said nasties to enter my beer. An airlock is not a great method of sanitizing air, but it's better than nothing. It also, as I said above, avoids a step which could also introduce bugs. The less touch points the better IMHO, but there's more than one way to skin a cat.

Fact is, a lot of us over-engineer our solutions to the point that benefits are lost to the effort required to gain them. We made perfectly fine beer back when we didn't know to cold crash.

 

[hoppus]

I just woke up so maybe I'm missing something, but what's the advantage of using a stopper to create a vacuum? Won't air simply rush in once you remove the stopper to rack the beer? Not that I'm worried about infecting already fermented beer, but at least with a vodka/everclear filled airlock may be killing some of the potential bugs.

 

[LBussy]

I just woke up so maybe I'm missing something, but what's the advantage of using a stopper to create a vacuum?

Probably nothing, but it's Sunday morning and more than a few of us have nothing better to do than argue the little things.

 

[hoppus]

Probably nothing, but it's Sunday morning and more than a few of us have nothing better to do than argue the little things.

This is why I love homebrewtalk

 

[stompbox]

I just woke up so maybe I'm missing something, but what's the advantage of using a stopper to create a vacuum? Won't air simply rush in once you remove the stopper to rack the beer? Not that I'm worried about infecting already fermented beer, but at least with a vodka/everclear filled airlock may be killing some of the potential bugs.

Not necessarily, if you allow the beer to regulate back to room temp before you open it.

Thanks to all the insight. I have had suck back with the s-type lock as well as a blowoff tube. I started with the S-type and then switched to a blow off. Situation then was more extreme as I sat the carboy out in the snow instead of a fridge.

The plastic carboys flex a lot and can create a lot of vacuum.

I pit my first batch in the fridge this AM using the simple suggestion of foil. I have 2 more batches to go once this one is done.

 

[seigex]

I've only been doing it since '91 or so. Neither the S lock nor the 3-piece will suck back through if they are filled correctly. If they are not they will suck some through (which is why I recommend vodka) and then stop.

I have experimented with using solid stoppers in empty carboys (which creates a larger vacuum because of the volume of air) and with new stoppers I can get them to seal ~75% of the time and of those they suck in about 50% of the time. With older stoppers where I assume the rubber is hardened, nearly 90% of them fail and pass air. I share this because most people are not obsessive-compulsive enough to try all this themselves.

Now *if* you can get a good seal, and *if* you keep from pulling the stopper in, then it's a superior method IMHO because it will also de-gas the beer at the same time. This is not often done by brewers but our wine-making brethren know it will definitely help a liquid clear faster. For this I have used the orange rubber caps, the plugs that come with them, and a hose clamp around the top. The more headspace is in the carboy the greater the effect. If there is liquid to the top you will likely not develop any vacuum.

So, apologies for what sounded like an extremely dismissive treatment of your advice. It was pre-coffee and not meant to be offensive. I'm just going by my experience. I feel for most people that simply leaving a perfectly good airlock on there, avoiding the opportunity to infect the beer by switching stoppers, and using something which will not have any negative effects if suckled in, will be the better solution.

Incidentally, I tried this with a 6 gallon Better Bottle and their stopper/airlock setup. 5 gallons of product in a 6 gallon BB will leave enough head space to create a profound vacuum that will start to collapse the bottle.

So your issue with my technique which I've had no issue for 8 years with, is purely anecdotal, as are mine. But you've been brewing since '91 or so, so what do I know?

ETA (since you edited after I began to reply):

Simply because you can find other people doing the same thing does not necessarily mean it is correct or better.

Not like Yooper knows anything about homebrewing or anything.

A refrigerator is a horribly dirty place, full of all sorts of spoilage microorganisms. My method assumes a large possibility of not forming a good seal. That being the case I do not want to create a channel with which gravity and in-rushing air will be utilized by said nasties to enter my beer. An airlock is not a great method of sanitizing air, but it's better than nothing. It also, as I said above, avoids a step which could also introduce bugs. The less touch points the better IMHO, but there's more than one way to skin a cat.

Fact is, a lot of us over-engineer our solutions to the point that benefits are lost to the effort required to gain them. We made perfectly fine beer back when we didn't know to cold crash.

Yes a refrigerator is dirty, my method creates a seal, I've never had a solid stopper sucked in, and I've never had a bad seal. Now I use a glass carboy, common sense would dictate that it's a bad idea with a better bottle. Whenever I used stoppers, I had to constantly refill the airlock with starsan/vodka and usually not before the seal was broken and air was being sucked in, especially during the initial cooling down of the beer when the majority of the vacuum is created as ambient co2 is being absorbed. Once the beer warms up the seal is released and all is good.

 

[tagz]

I either use a solid stopper or put the airlock on over double layer of Saran Wrap. Either way will seal the vessel and limit o2 exposure. Although many people use s-style air locks with no reported problems. I just like to limit o2 as much as possible.

 

[hoppus]

Not necessarily, if you allow the beer to regulate back to room temp before you open it.

My hat's off to you, I certainly do not possess that kind of patience :cross:

 

[LBussy]

So your issue with my technique which I've had no issue for 8 years with, is purely anecdotal, as are mine. But you've been brewing since '91 or so, so what do I know?

Um, no, being based on facts and research my issues are the opposite of anecdotal. I do however admit more research could be done but the overwhelming question to that would be WHY?

Not like Yooper knows anything about homebrewing or anything.

I don't know her personally, but I think she'd probably rather not have the responsibility of being right all the time. Just a guess. It works for her and works for you and that's fine. If the answers were all so black and white this would be a boring avocation.

FWIW, when I go to the trouble to cold-crash I usually also go to the trouble to cold-rack. Reason being we have precipitated simple proteins that become insoluble in colder liquids. If you let it warm up again you can again allow them to dissolve/disperse. You have also cooled the liquid to a level where the dissolved CO2 will not easily come out of solution. Warming allows it to potentially again do so, disturbing the sediment and making the beer more cloudy. Granted this is again a lot of work for a little gain but in for an inch, in for a mile.

Lastly, if you took from what I said that I use BB all the time that was not what I meant, I was giving a separate observation. Glass will support a vacuum where plastic will (obviously) not.

 

[seigex]

Um, no, being based on facts and research my issues are the opposite of anecdotal. I do however admit more research could be done but the overwhelming question to that would be WHY?

http://www.merriam-webster.com/dictionary/anecdotal

2 : based on or consisting of reports or observations of usually unscientific observers <anecdotal evidence>

Maybe I missed where you provided your scientific observations and reports, control methods etc...

I don't know her personally, but I think she'd probably rather not have the responsibility of being right all the time. Just a guess. It works for her and works for you and that's fine. If the answers were all so black and white this would be a boring avocation.

Amen! Which is why your first quote of my advice should not have been "... don't follow that advice." .. I was offering an option, something I use and has been tried and true, but your first response was to completely dismiss it, which is why we are even having this discussion, otherwise your post would have just been another option.

FWIW, when I go to the trouble to cold-crash I usually also go to the trouble to cold-rack. Reason being we have precipitated simple proteins that become insoluble in colder liquids. If you let it warm up again you can again allow them to dissolve/disperse. You have also cooled the liquid to a level where the dissolved CO2 will not easily come out of solution. Warming allows it to potentially again do so, disturbing the sediment and making the beer more cloudy. Granted this is again a lot of work for a little gain but in for an inch, in for a mile.

It doesn't take the beer warming back up to room temps to release the vacuum, just enough to defeat the seal, which for me usually happens as I'm preparing to siphon to my keg.

Lastly, if you took from what I said that I use BB all the time that was not what I meant, I was giving a separate observation. Glass will support a vacuum where plastic will (obviously) not.

Agree, though just to add if you have been rough with your glass, any cracks or compromised areas this will cause the glass to shatter if you drop it to too low of a temp.

 

[LBussy]

[...]your first quote of my advice should not have been "... don't follow that advice." .. I was offering an option, something I use and has been tried and true, but your first response was to completely dismiss it, which is why we are even having this discussion, otherwise your post would have just been another option.

I agree, which is why I followed shortly with:

So, apologies for what sounded like an extremely dismissive treatment of your advice. It was pre-coffee and not meant to be offensive. I'm just going by my experience. I feel for most people that simply leaving a perfectly good airlock on there, avoiding the opportunity to infect the beer by switching stoppers, and using something which will not have any negative effects if sucked in, will be the better solution.

 

[Demonantis]

I realize this only helps people with kegs, so I am sorry if you don't have one and this idea is completely useless for you. But couldn't you just cold crash in the keg and pull off all the yeast in the first glass. Bypassing the whole airlock issue.

 

[LBussy]

I realize this only helps people with kegs, so I am sorry if you don't have one and this idea is completely useless for you. But couldn't you just cold crash in the keg and pull off all the yeast in the first glass. Bypassing the whole airlock issue.

It's been my experience that you get a glass of yeast, then it settles again and you get another glass of yeast, and so on.

One way to do it is to cut the liquid line a bit short. Problem is you never know how short is short enough without wasting beer.

 

[stompbox]

It's been my experience that you get a glass of yeast, then it settles again and you get another glass of yeast, and so on.

One way to do it is to cut the liquid line a bit short. Problem is you never know how short is short enough without wasting beer.

Same here especially if you don't draw from it for a week or so.

 

[kombat]

Am I the only one who just replaces the airlock with a piece of sanitized aluminum foil, tightly wrapped around the mouth of the carboy and wrapped with a couple elastic bands?

 

[julioardz]

Am I the only one who just replaces the airlock with a piece of sanitized aluminum foil, tightly wrapped around the mouth of the carboy and wrapped with a couple elastic bands?

Nope. That's what I recommended earlier in this thread. It doesn't matter how you do it, you should just try to keep the opening to your carboy/bucket covered somehow, in case monkeys start flinging poo back and forth at each other. You don't want any of that falling in your beer.

 

[tagz]

It doesn't matter how you do it, you should just try to keep the opening to your carboy/bucket covered somehow, in case monkeys start flinging poo back and forth at each other. You don't want any of that falling in your beer.

/endthread

 

[BrewShenanigans]

I have been struggling with this issue as well. I usually use a conical for most of my fermentations in which I remove the blow off tube and seal the conical with a CO2 gauge before crashing. This creates a vacuum (if properly sealed). When I transfer the beer to kegs, I connect CO2 and pressurize the conical which pushes the beer without O2 exposure. The problem I have is when I use carboys. Wouldn't using an airlock or foil allow O2 to be drawn in allowing the beer to be oxidized or potentially contaminated? If the stopper method works (it doesn't get sucked into the carboy), could I just purge the head space with CO2 when I remove the stopper? This would quickly get rid of the O2 that is drawn in so it doesn't have time to affect the beer? If the stopper method is not advisable, what would be the best method to minimize O2 or contaminate exposure?

 

[mot]

As everyone has said, use S shapes. All I use now for this reason.

S shape suck back to they work both ways.

Your cold crashing so your done fermenting just put a solid bung on it. Or a Carboy cap.

 

[julioardz]

Wouldn't using an airlock or foil allow O2 to be drawn in allowing the beer to be oxidized or potentially contaminated?

Air outside of the carboy would be drawn in, but I've been using foil over carboys or leaving the bucket lid loosely placed on top when I cold crash and I have not noticed my beer becoming oxidized. I have also never had an infection.

I use only a primary. I don't splash my beer or wort around needlessly. I take gravity readings and samples only when needed. I cold crash soon after FG is reached or soon after I dry hop, and don't do any long term aging in a carboy or bucket. Most of my batches are bottled 2-3 weeks from brew day and are all gone within 6 months of that. Within that time, I have never had any oxidation that I perceive or would consider a flaw. Some batches start loosing freshness towards the end, but that's no different than a commercial beer that has sat around on a shelf for months. Most importantly I guess, I haven't had any of my beer with sour or cardboard tasting off flavors.

All that being said, there's nothing wrong with minimizing air exposure. I mean it's something we should be doing and the method you describe about flooding the head space with CO2 wouldn't hurt. If anything, you are only wasting CO2, but maybe you're gaining a few extra months of shelf life in your beer. I really don't know.

A simple cover over the opening that can vent the changes in pressure while cold crashing works for me. I'm not about over engineering the brewing process, like someone else stated in this thread. The simpler the better, as long as it produces great beer in the end. If I kegged and already had a CO2 tank on hand, maybe I would flood the head space as well, because it would be simple enough to do anyway.

 

[ColeR]

its easy, when your finished with fermentation, transfer your beer to a keg attach Co2 line and place keg in fridge. this way you don't have to worry about anything getting sucked in to the beer. Oh and fill the keg with Co2 before you put beer in it,

But you have to Keg your beer...

for bottling..

if you allow a small amount of air in to your carboy while you cold crash it, the existing Co2 in the Carboy is heaver than the air going in. this air will sit on top of the Co2, So just use the cotton ball idea to filter the air going in, or just use a solid bung.

CR-

 

[julioardz]

for bottling..

if you allow a small amount of air in to your carboy while you cold crash it, the existing Co2 in the Carboy is heaver than the air going in. this air will sit on top of the Co2, So just use the cotton ball idea to filter the air going in, or just use a solid bung.

CR-

The "CO2 blanket" has been debated before. Yes, CO2 may be heavier than O2, but gasses diffuse and mix. Without a one way valve or continuous purging, that headspace will eventually be air, a combination of O2, CO2, nitrogen, and whatever else is floating around in your environment. That probably doesn't matter much if you're cold crashing over a few days. The potential for infection and oxidation is there, but it's a minimal risk, from my experience, in my environment. That's why I don't do long term aging in buckets or carboys and why I don't transfer to secondary. I try to minimize how much I disturb the beer and prevent splashing around. Afterall, you have to get O2 into solution for oxidation to really have a significant effect on your beer.

As for the solid stopper. It may work sometimes, but it may suck the stopper in too far. I've never had one sucked all the way in, but I've had one get sucked in so far I couldn't get it out until I warmed the beer again. My whole point to cold crash was to drop yeast and add gelatin. Having to warm the beer up again meant I had to then cold crash again, this time with foil, so that the gelatin would be most effective. A carboy cap or a stopper with a lip around the top and some saran wrap could do the trick here if you want to completely seal it off and let it create a vacuum of sorts.

The cotton ball in the airlock is a good idea. Many probably already have cotton on hand, just like they do foil, so it's a quick simple, solution. For the overly paranoid, you can spray or soak the cotton in sanitizer first.

My whole point is, without splashing the beer around, either on the hot side of things or post fermentation, I have not noticed oxidation. Surface contact with air is probably not that bad over a short period. Long term aging that way may create a problem.

Just for kicks and to overly complicate this matter even more, what about filling a sanitized balloon or rubber glove with CO2 and flooding the head space with CO2? You can place the balloon over the opening and when it begins to suck in, it's pure CO2 over your beer. That's a bit rediculous in my book, but hey, if I had the means I would probably try it just for fun. But it would have to be with a rubber glove, because that would look funnier.

 

[cuda6pak]

If your airlock is filled with starsan or vodka, who really cares if some of it gets in?

 

[mot]

If your airlock is filled with starsan or vodka, who really cares if some of it gets in?

its the constant refilling depending on how long you are lagering or souring or whatever

 

[Xpertskir]

If your airlock is filled with starsan or vodka, who really cares if some of it gets in?

this....whole thread is much ado about nothing we are talking way less than .1%. People have more starsan in foam form when they originally fill the carboy

its the constant refilling depending on how long you are lagering or souring or whatever

That's mostly evaporation. Only time you are going to get a "sucking in" of airlock liquid is during a cooling phase, which even in lagering only happens once. Then it is just resting at a lagering temp.


this whole thread should RDWHAHB especially the poo flingers.

 

[mot]

this....whole thread is much ado about nothing we are talking way less than .1%. People have more starsan in foam form when they originally fill the carboy





That's mostly evaporation. Only time you are going to get a "sucking in" of airlock liquid is during a cooling phase, which even in lagering only happens once. Then it is just resting at a lagering temp.


this whole thread should RDWHAHB especially the poo flingers.

no its suck back, evaporation is not happening that quickly

 

[manocchs]

no its suck back, evaporation is not happening that quickly

Its not suck back. Suck back happens due to the pressure differential between the air inside of the carboy and the air outside of the carboy. The temperature of the air inside of the carboy is cooling and condensing (literally becoming more dense) causing a change in pressure that air from the outside tries to come in to equilibrate. This change only happens when the air is cooling or changing temperature in general. If the air and beer inside of the carboy started to heat up the air would become less dense and your airlock would start to bubble again. After the air has cooled and equilibrated with the environment it doesn't cause a change in the pressure anymore so nothing needs to get sucked in due to a pressure differential. This means suck back wont occur after the beer and air inside the carboy have become the same temperature as the air outside of the carboy so the only other reasonable explanation for the volume loss in the airlock is evaporation.

F*ck Yeah Science

 

[marinosr]

Clearly, I'm at work; there's no way I could have made it to page four otherwise.

 

[GJOCONNELL]

this thread went off the rails