Preventing O2 ingress when cold-crashing for lagering - ideas?

[Bobo1898]

If you have a food saver/vacuum sealer and an extra bottling bucket valve, put one of these together. I just inflate it, squeeze the air out a couple of times then put it on and cold crash.

I use a similar device to this, from Bobby and Brewhardware:

https://www.brewhardware.com/product_p/ccguardianv3.htm
Their cold crash guardian is great if you don't have time to DIY. This is set up to work with a gas post.

 

[MaxStout]

Well, the second DIY device I made yesterday (with the bucket valve) didn't hold CO2. Did a leak test and the spot where I taped it up onto the valve inlet was leaky. The first device I made is still holding gas. My taping job was better on that first one and the tubing I attached the balloon to is smoother than the valve, so better seal.

Nevertheless, I decided to get a Cold Crash Guardian from Brew Hardware (I needed a few other things, anyway). It should arrive in time for the cold crash. I'll just squirt in some CO2 from a tank, connect, then cold crash.

 

[General Sterling Price]

I've been wondering about the "suck back" issue lately, as I'll be attempting to cold crash my first brew this winter out in the garage. Would using a "colmatore" (like the winemakers) be useful? Seems like a larger 3 piece airlock with the option of "topping up" as the wine contracts. Any thoughts?

 

[tracer bullet]

Seems like a larger 3 piece airlock with the option of "topping up" as the wine contracts.

A goal with beer is to not have "air" go back into the fermenter - it contains oxygen which will start aging the beer and you'll be losing hops flavor. Hence the devices that fill with CO2, and then return that CO2 to the fermenter.

 

[Bobo1898]

I'm not too familiar with colmatori, but I know with standard 3-piece airlocks, oxygen will pass back through the water in the airlock when you cold crash. These looks like they fuction similarly, but I couldn't say for sure that it can allow air back in with a pressure drop.

Someone correct me if I'm wrong, but a device that can trap CO2 is probably the safest bet to avoid oxygen.

 

[day_trippr]

Certainly looks like it works the same as a three-piece.
S-locks do the same. The whole "lock" thing is clearly a misnomer

 

[General Sterling Price]

A goal with beer is to not have "air" go back into the fermenter - it contains oxygen which will start aging the beer and you'll be losing hops flavor. Hence the devices that fill with CO2, and then return that CO2 to the fermenter.

That's the stated purpose of this device as well. The airlock has a reservoir (an extension of the barrel contents), and what looks like a larger airlock portion that is more "user friendly" with regards to removing the center piece. It seems as though the water portion has enough to seal the air out, but not enough to suck into the chamber (ie: the water seal will break).....being larger than a normal airlock, it would allow the winemaker/brewer time to break the seal himself, and top up with something perhaps carbonated (like a beer maybe?). There's not much online about the techniques they use, but somehow they're able to avoid suck back without oxidizing their wines.

 

[MaxStout]

That's the stated purpose of this device as well. The airlock has a reservoir (an extension of the barrel contents), and what looks like a larger airlock portion that is more "user friendly" with regards to removing the center piece. It seems as though the water portion has enough to seal the air out, but not enough to suck into the chamber (ie: the water seal will break).....being larger than a normal airlock, it would allow the winemaker/brewer time to break the seal himself, and top up with something perhaps carbonated (like a beer maybe?). There's not much online about the techniques they use, but somehow they're able to avoid suck back without oxidizing their wines.

Do vintners typically cold crash their wines? If not, that's the reason they don't get oxidation

 

[tracer bullet]

Do vintners typically cold crash their wines? If not, that's the reason they don't get oxidation

Seems that they are concerned about some suck-back due to evaporation through the barrels. For the ones that use wood of course. So there may be some commonality there.

I didn't quite get what the device does, something about filling it with wine? I'm only familiar with the typical homebrew 3-piece airlocks, or the single piece with the sideways S shape in them. I looked somewhat carefully at it but the glass makes it hard to know what's going on. A little Google searching just got frustrating.

 

[General Sterling Price]

Do vintners typically cold crash their wines? If not, that's the reason they don't get oxidation

Winemakers are subject to the same challenges of oxidation as brewers.
They use airlocks the same way we do....except (as I've now discovered) that they also use them to mitigate the potential for oxidation VIA suck back.

Info is scarce, but it seems that the colmatore style airlock is basically like a regular 3 piece (in functionality), except it has a reservoir below the "airlock" section, it's larger (around the size of a 2 liter pop bottle), reservoir can be filled VIA the large tube in the airlock portion, and the center piece (lock) can be readily removed for filling.

 

[Spivey24]

I use a couple of those cold crash guardians. They work well enough, but it is not possible to make sure all oxygen is out of the device as there is always some space left in the bag and hoses. I figure after a few flushes though it is good enough.

Off topic question though. I usually cold crash to 33F for a few days. I get some suck back as the temperature drops and the balloon deflates some. But after a couple of days at 33F I will get a lot more suck back. I can’t quite figure out what’s going on. I have checked the device many times and it free flows back out of the bag with no issue. And the temp is monitored by the Tilts so I am reasonably sure of the temperature of the beer.

 

[Indian_villager]

Any interest in a ****** CO2 generator? As in 2L soda bottle with water, sugar, bakers yeast, use some carbonation caps and bs to attach to your lid. Include a tee between your CO2 generator and your fermenter and have the third leg of that tee go into a small container of star san, this way you don't risk over pressurizing your fermenter.

 

[tracer bullet]

I use a couple of those cold crash guardians. They work well enough, but it is not possible to make sure all oxygen is out of the device as there is always some space left in the bag and hoses. I figure after a few flushes though it is good enough.

I don't own one and don't know for sure, but aren't they hooked up at the beginning of fermentation? Like when you pitch your yeast and get the rest all set up? At that point in time O2 is fine, the yeast will use anything that is in the headspace as it dissolves into the wort. The device is just a slight extension of the headspace. I think anyhow - sound right?

 

[MaxStout]

Seems that they are concerned about some suck-back due to evaporation through the barrels. For the ones that use wood of course. So there may be some commonality there.

I didn't quite get what the device does, something about filling it with wine? I'm only familiar with the typical homebrew 3-piece airlocks, or the single piece with the sideways S shape in them. I looked somewhat carefully at it but the glass makes it hard to know what's going on. A little Google searching just got frustrating.

Unless I'm missing something, I don't see any advantage of this vs a standard airlock. If there is sufficient negative pressure within the FV, it looks like outside air will still be drawn through the airlock. My concern in this thread is O2 ingress, not just liquid suckback.

In any case, it doesn't appear to address my concerns. I have decided to use a CO2 capturing device, like the Cold Crash Guardian.

 

[MaxStout]

Any interest in a ****** CO2 generator? As in 2L soda bottle with water, sugar, bakers yeast, use some carbonation caps and bs to attach to your lid. Include a tee between your CO2 generator and your fermenter and have the third leg of that tee go into a small container of star san, this way you don't risk over pressurizing your fermenter.

If I were collecting CO2 from beer fermentation I don't see how generating more from sugar/bakers yeast would be necessary.

However, my issue today is I hadn't collected fermentation CO2 and now I need some to accommodate the cold crash.

Filling a Cold Crash Guardian from a CO2 tank would be a more elegant and less messy solution.

 

[mac_1103]

I use a couple of those cold crash guardians. They work well enough, but it is not possible to make sure all oxygen is out of the device as there is always some space left in the bag and hoses. I figure after a few flushes though it is good enough.

I don't own one and don't know for sure, but aren't they hooked up at the beginning of fermentation?

Yes, they're designed to capture fermentation gas and they will be fully flushed of O2 if you use them that way. They even come with a check valve. Filling something from a CO2 tank is only happening in this case because OP's other CO2 capture device failed.

 

[jerrylotto]

I agree this would do the trick. But if your able to pressurise the bucket (even if the pressure would be very low) you wouldn't need to transfer to a new bucket/keg in my opinion. Then you can just cold crash in the original and still avoid stuck-back. Or am I missing something?

Carbon dioxide dissolves in beer, and the amount that dissolves increases as temperature drops. So if you're going to cold crash you're going to have to be under pressure or you are going to pull a vacuum.

 

[MaxStout]

Yes, they're designed to capture fermentation gas and they will be fully flushed of O2 if you use them that way. They even come with a check valve. Filling something from a CO2 tank is only happening in this case because OP's other CO2 capture device failed.

I plan to purge the bag a couple times with CO2 from a tank, then fill again and connect. It looks like one of those collapsible water jugs people use for camping, with a hose and check valve attached. Rather clever, I think.

But I will use it with a blowoff jar next time.

 

[MaxStout]

Info is scarce, but it seems that the colmatore style airlock is basically like a regular 3 piece (in functionality), except it has a reservoir below the "airlock" section.

I think that's the crux. Since, AFAIK, vintners have no need to cold crash and tend to store fermenting wine at a fairly constant temp (wine people correct me if I'm wrong), there only needs to be enough barrier to hold back air ingress caused by minor temp changes. Just by looking at the pic I can see that the reservoir in the colmatore airlock does just that. It provides enough hydraulic pressure to withstand a relatively minor pressure differential. Therefore, it would be adequate to prevent O2 ingress only in cases of minor temp changes.

OTOH, those of who lager are dropping temps by 25 to 30F or so. The contraction of the CO2 in the headspace, combined with the increased solubility of gas in beer as temp decreases, requires more than just an airlock. The pressure differential can require several liters of CO2 from an external source.

I'm not trying to pick a fight. Just saying the colmatore airlock is the wrong tool for the job here.

 

[General Sterling Price]

I think that's the crux. Since, AFAIK, vintners have no need to cold crash and tend to store fermenting wine at a fairly constant temp (wine people correct me if I'm wrong), there only needs to be enough barrier to hold back air ingress caused by minor temp changes. Just by looking at the pic I can see that the reservoir in the colmatore airlock does just that. It provides enough hydraulic pressure to withstand a relatively minor pressure differential. Therefore, it would be adequate to prevent O2 ingress only in cases of minor temp changes.

OTOH, those of who lager are dropping temps by 25 to 30F or so. The contraction of the CO2 in the headspace, combined with the increased solubility of gas in beer as temp decreases, requires more than just an airlock. The pressure differential can require several liters of CO2 from an external source.

I'm not trying to pick a fight. Just saying the colmatore airlock is the wrong tool for the job here.

>I'm not trying to pick a fight.

No worries, buddy...I didn't get that impression. The forums are for sharing knowledge, and friendly debate.

>The contraction of the CO2 in the headspace, combined with the increased solubility of gas in beer as temp decreases, requires more than just an airlock.

Can you give me a ballpark figure at to how many CC's (or liters) of volume shrinkage a guy can expect from a 23 liter carboy FULLY topped up to the lip (ie: zero headspace) before a cold crash? Say from 68F to 35ish?

>Therefore, it would be adequate to prevent O2 ingress only in cases of minor temp changes.

This is kind of what I was hoping for in a sense...viewing the cold crash as a series of minor temp changes, and topped up throughout with perhaps a finished (CO2 laden) beer? Of course this depends on just how much space I'd have to make up.

*note - Sorry about the goofy "quotes"...I can't seem to figure out the quote function, OR "quit" a reply once I've brought up a reply box.

 

[tracer bullet]

Some % of wine could be lost through the wood barrels, right? Angel's share and all that in whisky terms. I wonder how much? They could have legit backfill issues.

I can't quit figure out how that glass thing works for wine. Google skills are failing me. It seemed like a standard 3-piece airlock for beer but seems there's more to it.

One could argue that a giant 3-piece airlock might do it, one where the little piece that pops up and down was big enough to hold a ton of CO2 (a liter perhaps) and not the couple of cc's they normally do.

 

[tracer bullet]

I think I figured out a little more. Look at the earlier picture. Note the wine in it... There is no headspace in the barrel. It's filled to the top, and into this airlock contraption's stem. Without the airlock it'd actually be overflowing.

Still it seems as this wine was drawn into the barrel, air would be drawn in through the top, that wine sitting up there would oxidize, and then get into the barrel. Maybe they count on it sitting up there above and not mixing in?

Hmm. I could be wrong, Maybe that helps the mystery a bit. Since we are already off topic anyhow, haha.

 

[tracer bullet]

Can you give me a ballpark figure at to how many CC's (or liters) of volume shrinkage a guy can expect from a 23 liter carboy FULLY topped up to the lip (ie: zero headspace) before a cold crash? Say from 68F to 35ish?

https://www.engineeringtoolbox.com/volumetric-temperature-expansion-d_315.html
Just over a half liter, apparently.

 

[Dland]

I cold crash after racked into kegs and spunded (carbonated by residual fermentation), or force carb after crash. Back when I bottled, I cold crashed after they were primed and carbonated.

Yes, there will be a little yeast sediment at bottom of keg or bottle, but not much more than what one would get racking and not wasting too much beer.

The whole thing with balloons and stuff kind of baffles me.

 

[General Sterling Price]

Some % of wine could be lost through the wood barrels, right? Angel's share and all that in whisky terms. I wonder how much? They could have legit backfill issues.

I can't quit figure out how that glass thing works for wine. Google skills are failing me. It seemed like a standard 3-piece airlock for beer but seems there's more to it.

One could argue that a giant 3-piece airlock might do it, one where the little piece that pops up and down was big enough to hold a ton of CO2 (a liter perhaps) and not the couple of cc's they normally do.

>Some % of wine could be lost through the wood barrels, right? Angel's share and all that in whisky terms. I wonder how much? They could have legit backfill issues.

Probably quite a bit, also (according to this article) the volumes they deal with are subject to tidal activity....

https://www-poderesanpierino-it.tra...tr_sl=it&_x_tr_tl=en&_x_tr_hl=en&_x_tr_pto=sc
>I can't quit figure out how that glass thing works for wine. Google skills are failing me.

It's not you....I had a hell of a time finding out what I have already...lol.

>One could argue that a giant 3-piece airlock might do it

That exactly what I was hoping/wondering about, they're quite large (this one has a 4 liter reservoir)....

https://www.colmatoriperbotti.com/
....of course trying to get one to fit a standard carboy might be difficult.

 

[General Sterling Price]

https://www.engineeringtoolbox.com/volumetric-temperature-expansion-d_315.html
Just over a half liter, apparently.

Oh wow......I was expecting a lot more!

 

[MaxStout]

>I'm not trying to pick a fight.

No worries, buddy...I didn't get that impression. The forums are for sharing knowledge, and friendly debate.

>The contraction of the CO2 in the headspace, combined with the increased solubility of gas in beer as temp decreases, requires more than just an airlock.

Can you give me a ballpark figure at to how many CC's (or liters) of volume shrinkage a guy can expect from a 23 liter carboy FULLY topped up to the lip (ie: zero headspace) before a cold crash? Say from 68F to 35ish?

>Therefore, it would be adequate to prevent O2 ingress only in cases of minor temp changes.

This is kind of what I was hoping for in a sense...viewing the cold crash as a series of minor temp changes, and topped up throughout with perhaps a finished (CO2 laden) beer? Of course this depends on just how much space I'd have to make up.

*note - Sorry about the goofy "quotes"...I can't seem to figure out the quote function, OR "quit" a reply once I've brought up a reply box.

It can be a lot. I'd say the biggest factors are headspace (CO2 contraction inside the FV), and amount of dissolved CO2 already in the beer (how much more will dissolve when dropping temp, etc). Contraction of the beer itself contributes some to the effect. I typically rack around 6 gallons into a 7 gal FV, so I don't leave much headspace. In the past I had less than 1/2 gallon suckback.

Wish I had a better answer, but there are so many variables it's difficult to predict.

Someone around here has a suckback calculator, but I can't find it. There's some discussion of volumes here.

I'd say plan for more than you think you need. I ordered the CO2 collector thingy from Brew Hardware. I'll find out how well it works in coming weeks.

 

[mashdar]

https://www.brewhardware.com/product_p/ccguardianv3.htmedit: oops, looked and didn't see this yet, but I missed bobo's post above.

 

[mac_1103]

edit: oops, looked and didn't see this yet, but I missed bobo's post above.

That's OK, he missed wepeeler's above his.

 

[doug293cz]

Off topic question though. I usually cold crash to 33F for a few days. I get some suck back as the temperature drops and the balloon deflates some. But after a couple of days at 33F I will get a lot more suck back. I can’t quite figure out what’s going on. I have checked the device many times and it free flows back out of the bag with no issue. And the temp is monitored by the Tilts so I am reasonably sure of the temperature of the beer.

The first bit of deflation is due to gas volume contraction due to the temperature drop. The continued deflation is from additional CO2 being absorbed into the beer, since at a constant CO2 partial pressure, the beer will hold more CO2 at a lower temperature.

Brew on