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General Category => Equipment and Software => Topic started by: majorvices on June 08, 2021, 10:59:52 PM

Title: Using collapsable bags to displace o2 during racking/packaging
Post by: majorvices on June 08, 2021, 10:59:52 PM
Been playing around with this for a few batches and it works. Fill the bag with co2, attach in place of air lock and the co2 in the bag displaces the head space.
 (https://uploads.tapatalk-cdn.com/20210608/8b066261bad80eed901beffed14b64d3.jpg)

Bottled a couple 5 liter batches today without a hitch. I haven't tried it on 5 gallon batches yet. Might need to replace bag before end not sure.

here are the bags and the spigots if any one is interested

https://www.usplastic.com/catalog/item.aspx?itemid=122655
https://www.usplastic.com/catalog/item.aspx?itemid=136411



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Title: Re: Using collapsable bags to displace o2 during racking/packaging
Post by: hmbrw4life on June 09, 2021, 12:54:52 PM
Been playing around with this for a few batches and it works. Fill the bag with co2, attach in place of air lock and the co2 in the bag displaces the head space.
 (https://uploads.tapatalk-cdn.com/20210608/8b066261bad80eed901beffed14b64d3.jpg)

Bottled a couple 5 liter batches today without a hitch. I haven't tried it on 5 gallon batches yet. Might need to replace bag before end not sure.

here are the bags and the spigots if any one is interested

https://www.usplastic.com/catalog/item.aspx?itemid=122655
https://www.usplastic.com/catalog/item.aspx?itemid=136411



Sent from my iPhone using Tapatalk

Could you just attach your CO2 line to the rubber stopper, and slowly (<=1-2psi) do the same thing minus the need for the bag?
Title: Re: Using collapsable bags to displace o2 during racking/packaging
Post by: majorvices on June 09, 2021, 01:56:29 PM
Yep. I've done that. Sorta where I got the idea looking for better alternatives. The co2 pressure pops the bung out cuasing it to have to be constantly monitored. IN this particular instance I was bottling directly from the fermenter so that definitely wouldn't work.

Obviously if you have a vessel capable of being and holding pressure a tank of Co2 might be a better solution. Maybe not for bottling though since it puts pressure on the line and forces the beer out faster than you may want it.

Another thing that struck me is that if homewbrewers don't have co2 they could simply collect the co2 off their fermentation into the bag and use that in place of filling the bag.
Title: Re: Using collapsable bags to displace o2 during racking/packaging
Post by: hmbrw4life on June 09, 2021, 01:58:10 PM
Yep. I've done that. Sorta where I got the idea looking for better alternatives. The co2 pressure pops the bung out cuasing it to have to be constantly monitored. IN this particular instance I was bottling directly from the fermenter so that definitely wouldn't work.

Obviously if you have a vessel capable of being and holding pressure a tank of Co2 might be a better solution. Maybe not for bottling though since it puts pressure on the line and forces the beer out faster than you may want it.

Another thing that struck me is that if homewbrewers don't have co2 they could simply collect the co2 off their fermentation into the bag and use that in place of filling the bag.

Fair enough.

Have you seen an improvement in product, when bottling with CO2 in the headspace, as opposed to standard?
Title: Re: Using collapsable bags to displace o2 during racking/packaging
Post by: denny on June 09, 2021, 01:59:17 PM
Yep. I've done that. Sorta where I got the idea looking for better alternatives. The co2 pressure pops the bung out cuasing it to have to be constantly monitored. IN this particular instance I was bottling directly from the fermenter so that definitely wouldn't work.

Obviously if you have a vessel capable of being and holding pressure a tank of Co2 might be a better solution. Maybe not for bottling though since it puts pressure on the line and forces the beer out faster than you may want it.

Another thing that struck me is that if homewbrewers don't have co2 they could simply collect the co2 off their fermentation into the bag and use that in place of filling the bag.

Kinda like the party balloon a lot of people have started using.
Title: Re: Using collapsable bags to displace o2 during racking/packaging
Post by: BrewBama on June 09, 2021, 02:00:35 PM

Another thing that struck me is that if homewbrewers don't have co2 they could simply collect the co2 off their fermentation into the bag and use that in place of filling the bag.

That was my thought.



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Title: Re: Using collapsable bags to displace o2 during racking/packaging
Post by: hmbrw4life on June 09, 2021, 02:01:38 PM
https://www.brewhardware.com/product_p/ccguardianv3.htm
Title: Re: Using collapsable bags to displace o2 during racking/packaging
Post by: majorvices on June 09, 2021, 03:30:19 PM
https://www.brewhardware.com/product_p/ccguardianv3.htm
How bout that? Didn’t see the size but same concept.


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Title: Re: Using collapsable bags to displace o2 during racking/packaging
Post by: majorvices on June 09, 2021, 03:31:46 PM
Actually yeah, 2.5 gallon. This one is 5 gallons and cheaper option


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Title: Re: Using collapsable bags to displace o2 during racking/packaging
Post by: Visor on June 12, 2021, 04:41:09 PM
   I use Fast Ferments and just stick a plug in the airlock hole when I cold crash, the lid seal & plug hold what little vacuum is created during crashing. As for the bag thing, I've been using a supersized balloon of CO2 attached to the airlock when bottling for several years now. Probably accomplishes very little, but almost certainly doesn't hurt.
Title: Re: Using collapsable bags to displace o2 during racking/packaging
Post by: majorvices on June 12, 2021, 04:55:03 PM
   I use Fast Ferments and just stick a plug in the airlock hole when I cold crash, the lid seal & plug hold what little vacuum is created during crashing. As for the bag thing, I've been using a supersized balloon of CO2 attached to the airlock when bottling for several years now. Probably accomplishes very little, but almost certainly doesn't hurt.

I guess it's a bigger deal for me than it is for others. I never like racking a beer and displacing with air.  I much prefer a closed transfer system. The only time I am not closed transfering is when I am bottling and bottle conditioning and even with that I am considering using a CPBF to purge with Co2 first (not filling under pressure).

One of the big benefits is if you are racking and you accidentally screw up your process and bubbled get in the line -- that Co2 instead of air.

Another big bonus is the yeast cake is under Co2 instead of unfiltered air (unless you use a filter ;) )

FTR you can also purge your racking line if you have a "siphonless fermenter" by having a small amount of Co2 in your keg and attaching the line via a QDC with port "closed" -- the Co2 will purge the line pushing the air out that tiny hole that is on every single plastic spigot I have ever encountered (the reason for I have never completely fathomed).
Title: Re: Using collapsable bags to displace o2 during racking/packaging
Post by: Richard on June 12, 2021, 10:10:15 PM
I use that tiny little hole on the spigot to flush it with StarSan. I put a hose on the bottom (output) of the spigot and fill it with StarSan until it starts shooting out the little hole.
Title: Using collapsable bags to displace o2 during racking/packaging
Post by: majorvices on June 13, 2021, 01:27:45 AM
Utilizing those hidden options… love it! I believe when the idea struck me me to purge the racking line was when sani left over in the keg shot me in the face out of that little hole (insert joke here)


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Title: Re: Using collapsable bags to displace o2 during racking/packaging
Post by: Joe_Beer on June 13, 2021, 10:28:39 AM
Been playing around with this for a few batches and it works. Fill the bag with co2, attach in place of air lock and the co2 in the bag displaces the head space.

Great idea! I wonder how this would work as a bladder for collecting co2 during ferment. Wish I could re-cycle all that gas somehow and at least use it for purging a keg of starsan. Tried garbage bags but they are a little too thin for squeezing the gas back into the keg.
Title: Re: Using collapsable bags to displace o2 during racking/packaging
Post by: majorvices on June 13, 2021, 02:52:58 PM
Been playing around with this for a few batches and it works. Fill the bag with co2, attach in place of air lock and the co2 in the bag displaces the head space.

Great idea! I wonder how this would work as a bladder for collecting co2 during ferment. Wish I could re-cycle all that gas somehow and at least use it for purging a keg of starsan. Tried garbage bags but they are a little too thin for squeezing the gas back into the keg.

That definitely works. I've tried it. Great option for those folks who don't keg or have a Co2 rig. In fact, that got me to thinking that folks who insist on using a "secondary" should attach the "secondary" to the primary with a double hole bung and add the airlock on the "secondary". That way the "secondary" is purged with co2 (mostly).
Title: Re: Using collapsable bags to displace o2 during racking/packaging
Post by: ynotbrusum on June 13, 2021, 07:41:28 PM
I routinely stack up my clean kegs and use the fermenter CO2 to push sanitizer out of the first filled keg to a bucket and then pour into the next keg filling it and repeat.  You can also daisy chain them to go with multiple kegs for one fermentation, dropping them out as they become empty.  Easy use of CO2 and not wasting it - you could put the airbag in the first spot in line and give it a try.
Title: Re: Using collapsable bags to displace o2 during racking/packaging
Post by: RC on June 14, 2021, 12:12:09 AM
This is a great idea, and I love the idea of capturing and re-using the CO2 from fermentation.

That said, I do wonder how much O2 is ingressing during an open transfer from fermenter to keg, which is what I do. I use a siphon starter, and the hose is attached to the beer-out connector on closed, purged keg, which is filled until beer spills out of the opened PRV. There's always at least 1/2 gallon of beer left behind in the fermenter (a 7-gal Fermonster), usually it's ~3/4 gal.

Oxygen is not very soluble in liquid. In the 15-ish minutes it takes to fill my keg, I doubt enough oxygen has dissolved in the beer to the point where it has seeped below the top ~1 inch of beer in the fermenter. IOW, I doubt that the beer that actually gets into the keg has any oxygen in it due to the open transfer.

My doubts can be easily dispelled by data on oxygen ingress from open transfer, if anyone has any. Otherwise we're all just speculating, and I'll choose doing nothing (i.e. the KISS principle) over doing something if I can get away with it, which so far I have been able to.
Title: Re: Using collapsable bags to displace o2 during racking/packaging
Post by: majorvices on June 14, 2021, 01:16:29 PM
I agree, it may be overkill. Without any actual testing it is impossible to know if there is any effect of the final DO levels. And this method might be impossible to do with an auto-siphon.

I have been bottle conditioning most of my homebrews for the last couple of months and I am not purging the bottles before filling and I have to admit they are turning out pretty great (for me). And the ones I put in kegs with autosiphon turned out pretty great (for me) as well. So who knows? I may try to test it with a DO meter here in the next couple of months just for grins. It makes me feel better and, since I am lazy, it allows me to harvest the yeast at a later date since I don't feel there is any risk of added infection with my "kitchen air". Two great danes and a crazy cat -- not the cleanest home ever. ;)

Title: Re: Using collapsable bags to displace o2 during racking/packaging
Post by: neuse on June 14, 2021, 04:02:38 PM
I think a big factor is how long the bottles or keg sit before drinking them. I don't purge my bottles with CO2, but for the last couple of years I've been planning brew days so that I can start drinking a batch when it is carb'd up, rather than brewing ahead. It seems to help a lot in terms of hop aroma. That might be why experiences differ for different brewers. I like a low tech solution.
Title: Re: Using collapsable bags to displace o2 during racking/packaging
Post by: majorvices on June 14, 2021, 04:15:04 PM
With hop aroma fresher is always better. And oxidation is a big enemy if you are trying to retain those aromas. I have mostly been brewing German lagers and English style ales at home. Regardless, I think this would work extremely well for hoppy beers. And ... uhm, this is an extremely low tech solutions.  It's a collapsable plastic bag. ;)
Title: Re: Using collapsable bags to displace o2 during racking/packaging
Post by: RC on June 15, 2021, 12:30:14 AM
I agree, it may be overkill. Without any actual testing it is impossible to know if there is any effect of the final DO levels. And this method might be impossible to do with an auto-siphon.
I may try to test it with a DO meter here in the next couple of months just for grins. It makes me feel better and, since I am lazy, it allows me to harvest the yeast at a later date since I don't feel there is any risk of added infection with my "kitchen air". Two great danes and a crazy cat -- not the cleanest home ever. ;)

Outside air, specifically "garage air", is permanently in my fermenters until I fill them with wort. Unless you're in a clean room at NASA, IMHO worrying about outside air is probably not all that useful. But your point is taken, especially vis-a-vis harvesting at a later time. Probably a good idea to keep great dane slobber out of your harvests :-[.

One thing I wonder: if you test DO or TPO and get a very low reading, how do you know it's due to having very low ingress vs. having lots of ingress but all the O2 reacted with stuff already? Where I worked, we had temporary access to a very fancy, very expensive industrial-brewing DO meter, and it read below the machine's resolution of 13 ppb for the three batches we were able to test. Great! But this low is virtually impossible to achieve at any scale. Was this due to us being amazing brewers (answer: absolutely, definitely NOT), or was there a lot of ingress but all the O2 already reacted with stuff, which gave us that low reading?
Title: Re: Using collapsable bags to displace o2 during racking/packaging
Post by: majorvices on June 15, 2021, 01:20:58 AM
Were you using any oxygen scavenging ingredients like metabisulphite in the BT? We used "Beer Protect" (from Erbslöh) for a while and it brought our DO levels to ridiculously low levels. Also if it wasn't calibrated correctly (using a Beverly) then the levels were never correct.

Also my wife worked for Nasa for a few years. And I know some people who work for Nasa and Boeing. So clean room ... maybe!
Title: Re: Using collapsable bags to displace o2 during racking/packaging
Post by: RC on June 15, 2021, 01:34:52 AM
Didn't use any scavenging ingredients. It was several years ago, but the brand name of Beverly sounds correct. We had the rep there at the time, that's how we "borrowed" it...the darn thing better have been calibrated correctly, since the rep was right there watching me!

Very cool that your better half worked at NASA, btw...
Title: Re: Using collapsable bags to displace o2 during racking/packaging
Post by: majorvices on June 15, 2021, 01:47:08 AM
There are 2 ways to calibrate it. It will give you decent results PPM calibrating with just Co2, like off a tank. But if you want PPB you have to use the calibration gas. Took me a while to figure that out because we had stupid low levels that were unrealistic. Also wasn't cheap, I believe it was about $600 for the calibration gases.
Title: Re: Using collapsable bags to displace o2 during racking/packaging
Post by: RC on June 15, 2021, 02:44:25 AM
There are 2 ways to calibrate it. It will give you decent results PPM calibrating with just Co2, like off a tank. But if you want PPB you have to use the calibration gas. Took me a while to figure that out because we had stupid low levels that were unrealistic. Also wasn't cheap, I believe it was about $600 for the calibration gases.

Never heard of calibration gas. But yeah I thought our levels were too low to be realistic...

Anyway, my overarching point is that I think we homebrewers can get away with a lot more than we think we can, whether it comes to pitch rate, or DO, or mash temp, or cleaning/sanitizing, or...(fill in the blank)...

Of course, not having the pressure to sell our beer is a huge plus.
Title: Re: Using collapsable bags to displace o2 during racking/packaging
Post by: Visor on June 16, 2021, 10:14:14 PM
I think a big factor is how long the bottles or keg sit before drinking them. I don't purge my bottles with CO2, but for the last couple of years I've been planning brew days so that I can start drinking a batch when it is carb'd up, rather than brewing ahead. It seems to help a lot in terms of hop aroma. That might be why experiences differ for different brewers. I like a low tech solution.

   I've never messed with the hassle of purging bottles, I figure the beer pushes the air out as it fills and what little mixing that does take place with the tiny surface area in a bottle during the 5 or 10 seconds it takes to fill can't be adding any consequential amount of DO, and bottle conditioning should clean most of that up. I'll admit that my sense of taste isn't world class, but I don't have many batches that start tasting stale prematurely, and most of the ones that do seem to be Lagers like Marzens. I have a goodly number of beers on hand that are well over a year old that still taste great, many keep getting better with age. Most of those though had O.G.s well in excess of 60.
Title: Re: Using collapsable bags to displace o2 during racking/packaging
Post by: majorvices on June 17, 2021, 12:05:30 AM
I think a big factor is how long the bottles or keg sit before drinking them. I don't purge my bottles with CO2, but for the last couple of years I've been planning brew days so that I can start drinking a batch when it is carb'd up, rather than brewing ahead. It seems to help a lot in terms of hop aroma. That might be why experiences differ for different brewers. I like a low tech solution.

   I've never messed with the hassle of purging bottles, I figure the beer pushes the air out as it fills and what little mixing that does take place with the tiny surface area in a bottle during the 5 or 10 seconds it takes to fill can't be adding any consequential amount of DO, and bottle conditioning should clean most of that up. I'll admit that my sense of taste isn't world class, but I don't have many batches that start tasting stale prematurely, and most of the ones that do seem to be Lagers like Marzens. I have a goodly number of beers on hand that are well over a year old that still taste great, many keep getting better with age. Most of those though had O.G.s well in excess of 60.

Oh, I agree it is probably overkill. I also probably won't do it since I haven't noticed any issues on the bottle conditioned beers I have been brewing. But I have thought about it. That said "pushing the air out" is introducing some oxidation, and it's difficult to say how much oxygen the yeast actually does clean up without testing. I think that Homebrewers have a huge advantage over commercial beers since we can keep the cold with minimal jostling. Plus, if the beers start to go south we can notice immediately and drink them up.
Title: Re: Using collapsable bags to displace o2 during racking/packaging
Post by: Bilsch on June 19, 2021, 03:23:20 AM
Oxygen is not very soluble in liquid. In the 15-ish minutes it takes to fill my keg, I doubt enough oxygen has dissolved in the beer to the point where it has seeped below the top ~1 inch of beer in the fermenter. IOW, I doubt that the beer that actually gets into the keg has any oxygen in it due to the open transfer.

Actually oxygen is quite soluble in water/beer but does have a saturation limit of about 8ppm depending on the temperature. Just because the saturation point is a low number does not mean that the oxygen dissolves in slowly. The speed is relative to the concentration gradient. If there is little or no DO in your beer then the force to push it in there will be greater. And as the O2 that went into solution reacts with the antioxidants in said beer, that makes room for more to come in. It's a vicious circle.

Concentration gradient is also germane to the polymer CO2 bag idea being discussed in this thread. Since all plastics are oxygen permeable to a certain extent, some much more than others, this idea wont protect your beer from oxidation or staling. Unless your using a good (read expensive) barrier polymer for storing the CO2 (and the fittings and lines to connect them) then the clock is ticking on it's O2 concentration. Every minute the difference in oxygen concentration on the outside of the bag is pushing/forcing O2 molecules in the bag through the plastic and that process wont stop until the inside and the outside reach equilibrium.

In other words it's probably a waste of time trying to store a low oxygen gas in a plastic bag and expect it to be low oxygen for long.
Title: Re: Using collapsable bags to displace o2 during racking/packaging
Post by: RC on June 19, 2021, 06:13:48 AM
Actually oxygen is quite soluble in water/beer...

This is not correct. Oxygen is not very soluble at all. It's ~40 times less soluble than CO2 and only about twice as soluble as N2--itself being, for the most part, insoluble. Like N2, O2 is a non-polar solute trying to be dissolved in a polar solvent. That said, O2 makes a difference for better and for worse in very small amounts. Maybe this is why everyone thinks it's so soluble. But it's not.

The speed is relative to the concentration gradient. If there is little or no DO in your beer then the force to push it in there will be greater.

Also incorrect. If there is little or no DO in the beer, it won't take anything to add oxygen. The rate of dissolution will be rapid at first but will slow down tremendously as you approach equilibrium with the atmospheric concentration. It will slow down so much that it will be almost impossible to reach atmospheric concentration (but you'll get close). This is the same reason why chilling the wort happens so rapidly at first but slows down as you approach your groundwater temp. The first ~130 degrees of chilling happen in a few minutes but the final 20 degrees takes forever. So it is with O2 dissolution. The 2nd law of thermodynamics is a real b**ch.
Oxygen is not very soluble in liquid. In the 15-ish minutes it takes to fill my keg, I doubt enough oxygen has dissolved in the beer to the point where it has seeped below the top ~1 inch of beer in the fermenter. IOW, I doubt that the beer that actually gets into the keg has any oxygen in it due to the open transfer.

Concentration gradient is also germane to the polymer CO2 bag idea being discussed in this thread. Since all plastics are oxygen permeable to a certain extent, some much more than others, this idea wont protect your beer from oxidation or staling.
Reality kicks theory's butt on this one.

Oxygen is not very soluble in liquid. In the 15-ish minutes it takes to fill my keg, I doubt enough oxygen has dissolved in the beer to the point where it has seeped below the top ~1 inch of beer in the fermenter. IOW, I doubt that the beer that actually gets into the keg has any oxygen in it due to the open transfer.

In other words it's probably a waste of time trying to store a low oxygen gas in a plastic bag and expect it to be low oxygen for long.

Storing a low oxygen gas in a plastic bag is not at all what the OP was describing.
Title: Re: Using collapsable bags to displace o2 during racking/packaging
Post by: majorvices on June 19, 2021, 11:46:31 AM
Oxygen is not very soluble in liquid. In the 15-ish minutes it takes to fill my keg, I doubt enough oxygen has dissolved in the beer to the point where it has seeped below the top ~1 inch of beer in the fermenter. IOW, I doubt that the beer that actually gets into the keg has any oxygen in it due to the open transfer.

Actually oxygen is quite soluble in water/beer but does have a saturation limit of about 8ppm depending on the temperature. Just because the saturation point is a low number does not mean that the oxygen dissolves in slowly. The speed is relative to the concentration gradient. If there is little or no DO in your beer then the force to push it in there will be greater. And as the O2 that went into solution reacts with the antioxidants in said beer, that makes room for more to come in. It's a vicious circle.

Concentration gradient is also germane to the polymer CO2 bag idea being discussed in this thread. Since all plastics are oxygen permeable to a certain extent, some much more than others, this idea wont protect your beer from oxidation or staling. Unless your using a good (read expensive) barrier polymer for storing the CO2 (and the fittings and lines to connect them) then the clock is ticking on it's O2 concentration. Every minute the difference in oxygen concentration on the outside of the bag is pushing/forcing O2 molecules in the bag through the plastic and that process wont stop until the inside and the outside reach equilibrium.

In other words it's probably a waste of time trying to store a low oxygen gas in a plastic bag and expect it to be low oxygen for long.

Hey Blisch -- tell you what. I'll fill that bag with Co2 and let you inhale it. Then you tell me how much Co2 you think is in it. ;) It definitely displaces the fermenter with Co2 when used as I suggedsted.

Yeah, eventually that collapsable bag will exchange o2. Though these are extremely sturdy bags. They aren't exchanging o2 over the 1-2 hours I'm using them.

I'm guessing you either didn't entirely read the purpose I proposed or you are fixated my suggesting they could be a way to capture Co2 for bottle conditioners or secodnary users without acess to Co2. I still think they could be used for this as well. I think they will exchange very little gas in that period.
Title: Re: Using collapsable bags to displace o2 during racking/packaging
Post by: Bilsch on June 19, 2021, 10:32:24 PM
Actually oxygen is quite soluble in water/beer...
This is not correct. Oxygen is not very soluble at all. It's ~40 times less soluble than CO2 and only about twice as soluble as N2--itself being, for the most part, insoluble. Like N2, O2 is a non-polar solute trying to be dissolved in a polar solvent. That said, O2 makes a difference for better and for worse in very small amounts. Maybe this is why everyone thinks it's so soluble. But it's not.

Very or not very makes no difference in this instance as it only takes PPB to damage your beer. And what do you think the O2 does when it gets into the beer, sit there and do nothing? No it reacts with the antioxidants (your fresh beer flavor) and makes room for more oxygen. It really wouldn’t matter if the solubility limit was 100 PPB or 100 PPM because the limit will never be reached due to consumption. Your argument here is a non sequitor.

The speed is relative to the concentration gradient. If there is little or no DO in your beer then the force to push it in there will be greater.
Also incorrect. If there is little or no DO in the beer, it won't take anything to add oxygen. The rate of dissolution will be rapid at first but will slow down tremendously as you approach equilibrium with the atmospheric concentration. It will slow down so much that it will be almost impossible to reach atmospheric concentration (but you'll get close). This is the same reason why chilling the wort happens so rapidly at first but slows down as you approach your groundwater temp. The first ~130 degrees of chilling happen in a few minutes but the final 20 degrees takes forever. So it is with O2 dissolution. The 2nd law of thermodynamics is a real b**ch.

Did you happen to read what I wrote? You simply disagreed with my statement and then went ahead and said the same thing. But hey.. I’m glad we finally got that settled. ;)

Concentration gradient is also germane to the polymer CO2 bag idea being discussed in this thread. Since all plastics are oxygen permeable to a certain extent, some much more than others, this idea won’t protect your beer from oxidation or staling.
Reality kicks theory's butt on this one.

That is your answer?
How have you measured your reality?

Oxygen is not very soluble in liquid. In the 15-ish minutes it takes to fill my keg, I doubt enough oxygen has dissolved in the beer to the point where it has seeped below the top ~1 inch of beer in the fermenter. IOW, I doubt that the beer that actually gets into the keg has any oxygen in it due to the open transfer.

I’m glad you based your belief on solid scientific evidence like your doubts.
Instead of guessing, I measure.
For example: I recently did a study on the oxygen permeability of the silicone hoses in my system and found that for 0.75” id x 0.5” od silicone hose,  a permeability of 0.0386ppm per hour, per inch of length.  I also re-ran the experiment with a barrier polymer wrap on the outside of the same hose and reduced that number to 0.0203ppm per hour, per inch of length. 
(https://ibb.co/QHkJZFf)

https://ibb.co/gSW9qkX
Title: Re: Using collapsable bags to displace o2 during racking/packaging
Post by: Bilsch on June 19, 2021, 10:50:37 PM
Hey Blisch -- tell you what. I'll fill that bag with Co2 and let you inhale it. Then you tell me how much Co2 you think is in it. ;) It definitely displaces the fermenter with Co2 when used as I suggedsted.

Yeah, eventually that collapsable bag will exchange o2. Though these are extremely sturdy bags. They aren't exchanging o2 over the 1-2 hours I'm using them.

I'm guessing you either didn't entirely read the purpose I proposed or you are fixated my suggesting they could be a way to capture Co2 for bottle conditioners or secodnary users without acess to Co2. I still think they could be used for this as well. I think they will exchange very little gas in that period.

How about instead of inhaling and guessing we use the proper instrument to determine if that is the case or not? Sturdy.. is that a good rating of the O2 permeability of plastic? I read exactly what you posted and I am telling you that oxygen will get through your sturdy bag and into the headspace of your jar. Believe it or not.
Title: Re: Using collapsable bags to displace o2 during racking/packaging
Post by: majorvices on June 20, 2021, 12:00:35 AM
Hey Blisch -- tell you what. I'll fill that bag with Co2 and let you inhale it. Then you tell me how much Co2 you think is in it. ;) It definitely displaces the fermenter with Co2 when used as I suggedsted.

Yeah, eventually that collapsable bag will exchange o2. Though these are extremely sturdy bags. They aren't exchanging o2 over the 1-2 hours I'm using them.

I'm guessing you either didn't entirely read the purpose I proposed or you are fixated my suggesting they could be a way to capture Co2 for bottle conditioners or secodnary users without acess to Co2. I still think they could be used for this as well. I think they will exchange very little gas in that period.

How about instead of inhaling and guessing we use the proper instrument to determine if that is the case or not? Sturdy.. is that a good rating of the O2 permeability of plastic? I read exactly what you posted and I am telling you that oxygen will get through your sturdy bag and into the headspace of your jar. Believe it or not.


If I fill a collapsable bag (please view the particular one I posted, I'm not talking about a WalMart shopping bag) with Co2 ... it's going to be filled with Co2 for all intents and purposes. This is a laughable argument. And I'm the one who should be laughed at most for arguing about it when this really just feels like an attempt to troll for no other reason but to troll.
Title: Re: Using collapsable bags to displace o2 during racking/packaging
Post by: Bilsch on June 20, 2021, 02:14:15 AM
If I fill a collapsable bag (please view the particular one I posted, I'm not talking about a WalMart shopping bag) with Co2 ... it's going to be filled with Co2 for all intents and purposes. This is a laughable argument. And I'm the one who should be laughed at most for arguing about it when this really just feels like an attempt to troll for no other reason but to troll.

So when someone comes here with alternate viewpoint that questions the efficacy of your clever ideas it's trolling? My apologies. Apparently the bubble here at this forum is made from a science barrier polymer?

On the bright side though there has been progress. If say three or four years ago someone postulated that you should attempt keep the headspace of your still beer protected from oxidation by using a CO2 filled bag.. heads would have exploded.
Title: Re: Using collapsable bags to displace o2 during racking/packaging
Post by: majorvices on June 20, 2021, 02:58:12 AM
Yawn. Go away, Bryan. I am certain you can find something better to do than this. Go do something productive. Trolling is so beneath you.
Title: Using collapsable bags to displace o2 during racking/packaging
Post by: tommymorris on June 20, 2021, 03:08:55 AM
Back to the original post. I am doing that. My bag is smaller. During fermentation it fills with CO2. I then use it just like you have pictured when draining the fermenter into the keg. The only problem is, the bag probably had O2 in it before fermentation. I assume that O2 is still in there.

Here is a picture of mine waiting to be kegged.

(https://uploads.tapatalk-cdn.com/20210620/c0de609adc2b539ef5ce344167428b6e.jpg)

PS. I don’t add the bag until the beer is a few points from terminal gravity. I still have to let lots of CO2 out. It fills up fast.
Title: Re: Using collapsable bags to displace o2 during racking/packaging
Post by: majorvices on June 20, 2021, 12:04:48 PM
Tommy -- the ones I posted are completely collapsable. When they are devoid of air they lay completely flat. In fact, the lowest tech way I have found to make them completely void of air is just to suck on them, then sani the tube.

https://www.usplastic.com/catalog/item.aspx?itemid=122655
https://www.usplastic.com/catalog/item.aspx?itemid=136411

(https://www.usplastic.com/catalog/images/products/Bottles/400/67831psku.jpg)

Title: Re: Using collapsable bags to displace o2 during racking/packaging
Post by: tommymorris on June 20, 2021, 01:12:58 PM
Tommy -- the ones I posted are completely collapsable. When they are devoid of air they lay completely flat. In fact, the lowest tech way I have found to make them completely void of air is just to suck on them, then sani the tube.

https://www.usplastic.com/catalog/item.aspx?itemid=122655
https://www.usplastic.com/catalog/item.aspx?itemid=136411

(https://www.usplastic.com/catalog/images/products/Bottles/400/67831psku.jpg)
Mine maybe completely collapsable also. I haven’t tried sucking the air out. I’ll try that next time.