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Limiting oxidation: effect of purging headspace O2 in a bottle conditioned IPA

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Birrofilo

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@Miraculix

In answer to a post of yours earlier in this discussion, I bought today a cylinder with net 390g of liquid CO2, which will expand to 214 litres of CO2, for around €20 and I also needed a pression reducer which cost around €20 (can't find the exact prices now, but I am not wrong by much).

That kind of cylinder is not refillable. 214 litres is a lot of capping...

I also bought 3 metres of a silicon hose with an internal diameter of 3mm online for €9.

I will keep the cylinder outside away from sun rays. CO2 can be dangerous in high concentrations (or whatever it's the right word...) and I want to take into account the possibility of some defective valves.
 

Birrofilo

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If you REALLY want to get anal about preservation, there's an article on the Low Oxygen Brewing website where a brewer actually stored his capped beer bottles in an empty keg, then capped the keg and and purged with CO2. That way any ingress of oxygen would be impossible across the beer cap barrier since the O2 in the keg had virtually been eliminated. A bit more than I'm interested in doing, but apparently it worked.
A much more elegant, effective and cheap method would be to "wax" the bottles. That is ideally done when your bottles will have to be consumed more than one year, or even several years, after brewing. Wax gives a cheap and perfect protection from outside air. Crown caps leak in the long run, wax doesn't.

You can also impress a design on the wax, bringing the "cool factor" an order of magnitude higher ;-)

 

Vale71

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Crown caps leak in the long run, wax doesn't.
Wax has an oxygen permeability up to 10 times that of PET. PET bottles are so bad that they're considered unsuitable for beer storage. Wax is up to 10 times worse.You do the math. But it certainly looks cool even though it serves no practical purpose.
 

Birrofilo

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Wax has an oxygen permeability up to 10 times that of PET. PET bottles are so bad that they're considered unsuitable for beer storage. Wax is up to 10 times worse.You do the math. But it certainly looks cool even though it serves no practical purpose.
Wax is used for long-term storage for wine and beer since ages. I don't want to say that time-honoured traditions are necessarily right. But I would like to see some evidence that they are wrong and that wax serves "no practical purpose".

Also, PET is unsuitable for long-term storage but that means an entire bottle of PET. In our case, the bottle is made of glass, and you use wax as an additional shield which must protect you from the slow and tiny loss than a crown cap can have. You only have to fill that tiny gap. The quoted text suggests a keg filled with CO2 where to store bottles. I suggest wax in its stead.

I don't think that your comparison with PET makes any sense (unless you want to say that one can actually use PET instead of wax, which is also done, I don't know the English for a fascetta, that plastic wrap-up around the neck of the bottle). Glass doesn't leak (PET does). You use wax to close that tiny gap, not to preserve the entire beer in a wax bottle.

In fact, that's another method for long-term conservation of beers: cork and a plastic fascetta, or crown cap and plastic fascetta. That's easier in any case than keeping a keg idle for years for storing bottles. You do the math.

You might have a point in this: that even in long-term storage maybe a way is needed for some CO2 to escape (the beer is not stabilized, or the wine, so there is always an albeit tiny amount of activity going on in the bottle) and therefore wax is used because it's much less transpirating the cork, or crown cap, but it does allow that tiny bit of CO2 to escape.

If you use a fascetta, you have to practice two tiny holes in them (as you can see in any bottle of wine, the fascetta always has two small holes).

If you prefer, you can also apply the plastic fascetta, that's very easy:

(notice the holes which come pre-punched into the fascetta). (A fascetta is also called a capsula).

It's way better than the keg filled with CO2 IMHO, but YMMV.

The wax has the cool factor on its side :)
 
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Vale71

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Wax is used for long-term storage for wine and beer since ages. I don't want to say that time-honoured traditions are necessarily right. But I would like to see some evidence that they are wrong and that wax serves "no practical purpose".
Since you're the one claiming that wax protects from oxidation the onus is on you to prove it. That's how science work, unless what you're claiming is to be taken as just your opinion which would be scientifically neither right nor wrong but simply irrelevant.

Wineries used wax sealant to prevent counterfeiting and tampering of expensive wines. Nowadays it's probably done just for looks. It most definitely wasn't done to prevent oxygen ingress as natural cork is already impenetrable to oxygen (plastic corks are but they aren't used for expensive wines) so if this is your "proof" that wax protects from oxygen ingress you're already wrong from the get go.

As to my comparison with PET it was used to illustrate how permeable wax is without using actual numbers. The point I was making is that using a highly gas permeable material to "protect" from oxygen ingress is utterly pointless. If the materials used in the package (in this case glass bottle and metal cap + PVC compound sealant) are already much less permeable than the wax then you're not adding any protection at all. I will concede that it looks "cool" though, it simply does nothing at all to address the actual issue.

BTW plastic in general is highly gas permeable, so using anything plastic to protect from O2 ingress is usually not very effective.
 

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@Miraculix

In answer to a post of yours earlier in this discussion, I bought today a cylinder with net 390g of liquid CO2, which will expand to 214 litres of CO2, for around €20 and I also needed a pression reducer which cost around €20 (can't find the exact prices now, but I am not wrong by much).

That kind of cylinder is not refillable. 214 litres is a lot of capping...

I also bought 3 metres of a silicon hose with an internal diameter of 3mm online for €9.

I will keep the cylinder outside away from sun rays. CO2 can be dangerous in high concentrations (or whatever it's the right word...) and I want to take into account the possibility of some defective valves.
Thank you very much for the information, much appreciated!

This is in a range of investment costs that I would be willing to take. Would you mind sharing direct links to the specific items you bought? If you don't want to share them here, pm would be fine as well. I just have no idea what I would need to look for, this would give me a good idea about where to start here in Germany.

Thanks!
 
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Miraculix

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Since you're the one claiming that wax protects from oxidation the onus is on you to prove it. That's how science work, unless what you're claiming is to be taken as just your opinion which would be scientifically neither right nor wrong but simply irrelevant.

Wineries used wax sealant to prevent counterfeiting and tampering of expensive wines. Nowadays it's probably done just for looks. It most definitely wasn't done to prevent oxygen ingress as natural cork is already impenetrable to oxygen (plastic corks are but they aren't used for expensive wines) so if this is your "proof" that wax protects from oxygen ingress you're already wrong from the get go.

As to my comparison with PET it was used to illustrate how permeable wax is without using actual numbers. The point I was making is that using a highly gas permeable material to "protect" from oxygen ingress is utterly pointless. If the materials used in the package (in this case glass bottle and metal cap + PVC compound sealant) are already much less permeable than the wax then you're not adding any protection at all. I will concede that it looks "cool" though, it simply does nothing at all to address the actual issue.

BTW plastic in general is highly gas permeable, so using anything plastic to protect from O2 ingress is usually not very effective.
Jeeez what is wrong with you mate. Anti anti anti, all the freaking time.

He very well explained that the wax is just used to close the small gap between cap and bottle. This leaves a surface area of wax that would be able to transfer O2 of how much.... 0.0002 square millimeters? And you are comparing this to the whole surface area of a pet bottle? Now tell me again about being scientific please.
 
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Taket_al_Tauro

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Thank you very much for the information, much appreciated!

This is in a range of investment costs that I would be willing to take. Would you mind sharing direct links to the specific items you bought? If you don't want to share them here, pm would be fine as well. I just have no idea what I would need to look for, do this would give me a good idea about where to start here in Germany.

Thanks!
Very interested as well... No idea where to find CO2 equipment that cheap. So far I only stumbled upon those mini keg chargers...quite cheap but also relatively tiny amounts of CO2 in those cartridges. And no precise idea on how to put together a practicable device for purging headspaces.
I already allowed myself to send him a PM about this, since I guess it only concerns us Europeans, but if he wants to share here, why not!
 

Miraculix

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Very interested as well... No idea where to find CO2 equipment that cheap. So far I only stumbled upon those mini keg chargers...quite cheap but also relatively tiny amounts of CO2 in those cartridges. And no precise idea on how to put together a practicable device for purging headspaces.
I already allowed myself to send him a PM about this, since I guess it only concerns us Europeans, but if he wants to share here, why not!
I actually saw some regulators in the 20 euro range during a quick online search but I have no idea of they would fit the purpose. I have simply no clue about connection types, pressures, what type if container to connect to it and so on...
 
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Vale71

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Jeeez what is wrong with you mate. Anti anti anti, all the freaking time.

He very well explained that the wax is just used to close the small gap between cap and bottle. This leaves a surface area of wax that would be able to transfer O2 of how much.... 0.0002 square millimeters? And you are comparing this to the whole surface area of a pet bottle? Now tell me again about being scientific please.
Sorry, didn't realize that being against misinformation was a bad thing. Oh well, you learn something new every day.

I never compared the area of anything with anything else, I was merely pointing out how extremely gas permeable wax is by comparing it to a material that is known to be so permeable as to be unsuitable for packaging O2-sensitive beverages. That was to avoid using actual numbers and units that might be hard to deal with by some. Apparently that was a bad idea.

Area is clearly irrelevant as the area of the covering material is obviously identical to the area covered. All that matters is the gas permeability of the covering material. My point was that it's pointless to use an extremely gas permeable material as "additional protection" against oxygen ingress as you won't be reducing oxygen ingress at all. If you want to effectively protect against oxygen ingress you need to use materials with low oxygen permeability (should be quite obvious right?) and wax is not one of them by a far stretch. So if you want to wax your beer bottles because you think they look cool then fine, but if you think you're protecting your beer from oxygen ingress than you're just fooling yourself.
 

Miraculix

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Sorry, didn't realize that being against misinformation was a bad thing. Oh well, you learn something new every day.

I never compared the area of anything with anything else, I was merely pointing out how extremely gas permeable wax is by comparing it to a material that is known to be so permeable as to be unsuitable for packaging O2-sensitive beverages. That was to avoid using actual numbers and units that might be hard to deal with by some. Apparently that was a bad idea.

Area is clearly irrelevant as the area of the covering material is obviously identical to the area covered. All that matters is the gas permeability of the covering material. My point was that it's pointless to use an extremely gas permeable material as "additional protection" against oxygen ingress as you won't be reducing oxygen ingress at all. If you want to effectively protect against oxygen ingress you need to use materials with low oxygen permeability (should be quite obvious right?) and wax is not one of them by a far stretch. So if you want to wax your beer bottles because you think they look cool then fine, but if you think you're protecting your beer from oxygen ingress than you're just fooling yourself.
Glad to see that you are not blocking me anymore. Thank you.

The wax will limit the amount of oxygen close to the permeable mini gap between cap and bottle big time. As the amount of transferred oxygen through a permeable substance is a function of permeability and the amount of oxygen present, the result will be that there is much less oxygen going through the gap with the additional wax protection than without it. As without it, there would be direct contact with the air.
 
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Vale71

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Glad to see that you are not blocking me anymore. Thank you.
Hopefully I won't have to regret it.

The wax will limit the amount of oxygen close to the permeable mini gap between cap and bottle big time. As the amount of transferred oxygen through a permeable substance is a function of permeability and the amount of oxygen present, the result will be that there is much less oxygen going through the gap with the additional wax protection than without it as without it, there would be direct contact with the air.
That's not how gas diffusion through membranes work. Even if you have a multi-layered membrane the rate will only be limited by the layer with the least permeability.

Let's try to explain using an analogy with water and funnels. Let's say you have water running through a system of funnels connected serially. One funnel has a throughput of 10 liters per minute and this funnel cannot be exchanged for a different funnel and all the water has to pass through this funnel. This funnel cleraly represents our crown cap. Let's say that you can now place a second funnel before this funnel and you can choose between a funnel that has a throughput of 1000 liters per minute and one that only lets 20 liters per minute through but keep in mind that all water still has to pass through the first funnel that has a 10 liters per minute rate. Which combination of funnels will give the highest total throughput? There is only one correct answer of course. ;)
 

Birrofilo

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Since you're the one claiming that wax protects from oxidation the onus is on you to prove it. That's how science work, unless what you're claiming is to be taken as just your opinion which would be scientifically neither right nor wrong but simply irrelevant.

Wineries used wax sealant to prevent counterfeiting and tampering of expensive wines. Nowadays it's probably done just for looks. It most definitely wasn't done to prevent oxygen ingress as natural cork is already impenetrable to oxygen (plastic corks are but they aren't used for expensive wines) so if this is your "proof" that wax protects from oxygen ingress you're already wrong from the get go.
You don't seem to be much into wine.
Natural cork is quite permeable to oxygen, and this is why it is used for non-stabilized wine, because wine must "breathe" or, better, it must expel CO2 from the bottle (although probably there is some oxygen intake which is also useful or necessary).
After the seasoning in the bottle (long-aged wines are aged first in the cask, then in the bottle) the necessity arises to reduce the gas-permeability, but in any case to allow the minimal gas exchange which is always needed. That is when the wax, or the capsula, is applied, the capsula always has the holes.

Wax is not a barrier against counterfeiting: it's extremely easy to use (just like the fascette). You see that in the video. That sort of "rubber stamp" which is used to impress a trademark on the wax is also very easy to counterfeit, much more than the label which you have to counterfeit in any case.

Your approach is too much science and not enough life. Just ask any proper winery why the capsules are perforated and they will let you that it is to let a minimum of gas exchange. The capsule would not be sufficiently gas-permeable. If you go to any good wine-shop and examine the bottles, you will see that all (and I mean all) wine capsules are perforated for this reason. Look well, the holes are tiny, but they are always there.

What I "claim" is demonstrated by "empirical evidence" which is in front of our eyes every day. If you search around the internet, you will find people who wax Belgian beer destined to long aging because crown caps are not reliable enough, and they will tell you that, in their experience, this solved the problem of crown tap leakage. And why should I not trust them? Because I went up looking on the internet the gas-permeability of wax just to contradict them? I am sure they are reliable because they talk through real-life experience and not abstract theory.

IMHO you have a wrong approach to problem-solving, too analytical. I prefer to start from the experience of people solving problems, not from equations and physical properties. You are obviously free to ignore the experience of experienced people, and to go on having leaking crown caps or storing bottles into CO2-filled kegs, of course. But I do bet that, when you begin storing Belgian ales for a couple years, you will give a try to wax :)
 
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Birrofilo

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Thank you very much for the information, much appreciated!

This is in a range of investment costs that I would be willing to take. Would you mind sharing direct links to the specific items you bought? If you don't want to share them here, pm would be fine as well. I just have no idea what I would need to look for, this would give me a good idea about where to start here in Germany.

Thanks!
I went to one of those hardware store chains, Leroy Merlin. Similar chains in Italy are Bricofer, Obi and others. There you have to look for the soldering sector. You will find there cylinders with oxygen, or CO2, and also argon and argon-CO2 mix.

There are let's say three kinds of cylinders that you can buy.

The large and serious cylinder, heavy to transport, which is used e.g. by people kegging the beer, or for real work in apartment restructuring etc. Those are refillable cylinders. They are filled at a very high pressure and have specific "valves" (pression reducers).
This is an example: Bombola Co2 da 4Kg Nuova ForHome® Ricaricabile Con Valvola Residuale Certificata
They might be overkill if the purpose is only capping.

Then you have the smaller, non-refillable cylinders. In the case of Oxygen, they come in two formats: small, around 24 litres of expanded gas, they are very light when you take them in your hand they seem empty, and "larger", not in physical dimensions but in weight and capacity, they hold more than 200 litres of expanded gas, the cylinder itself weights 1200g. Both kinds use the same pression reducers I do believe.
The pression reducer is often termed simply "for non-refillable cylinders", or it is termed "M10x1"

This is one example, a "heavier" CO2 non-refillable cylinder: Bombola a gas co2 AWELCO 0.95 L. Prezzo online | Leroy Merlin
The connector is called "filetto europeo", European thread, because that's a standard for those kind of cylinders. Basically M10x1, European thread or "for non-refillable cylinders" will get you the right pression reducer.

Note, though, that oxygen cylinders (which can be used for wort oxygenation, with a 0,5 micron aeration stone) need a specific pressure reducer, which is marked as "oxygen".

Actually now that I think about it, M10x1 is the one for oxygen, and generic "for non refillable cylinders" is for generic gas. Maybe (I did not test it) the two threads are different. [EDIT: tested, the thread is the same]

In any case, the assistant will give you the right pression reducer for the CO2 cylinder and the right pression reducer for the O2 cylinder. These cylinders typically are not sent by courier for the danger of explosion when left in hot temperatures, so you'll have to go to the hardware store.

Examples: Riduttore di pressione. Prezzo online | Leroy Merlin

The gas gets out through a "hose connector", you can couple there, typically, a hose with 3mm internal diameter. I bought this on Amazon.


A silicon hose is very good because you can immerse it with the aeration stone in a vessel with water and sanitize, or even sterilize it with a microwave oven without having to touch the stone to fit the hose again, you just sanitize all together.

Oxygen is easily inflammable and CO2 can suffocate you and actually kill you, so this stuff is to be kept with some caution. I keep the cylinders outside but NOT in direct sunlight, that creates a danger of explosion.

In order to use them, you just close the tap on the reducer, fill the reducer on the cylinder, and then open the tap for the gas to get out. No particular manoeuvers.

The cylinder does not stand right by itself so I will use a bottle-holder to keep it up. One hand manovrates the gas tap, the other keeps the silicon hose inside the bottle. I will report here how it worked.

Just as we are there, this is an oxygen cylinder:

That's, again, more than 200 litres of oxygen. If you oxygenate beer (at pitching stage) with 1 minute at 1 litre/minute of flow, you have more than 200 batches of beer for this cost (plus the cost of the pressure reducer).

Oxygen for "soldering" is basically identical to the one used for medical purposes, for our goals. You will find very pure gases in there, no oils or other unwanted stuff.

Another option is to use the SodaStream cylinders with an adapter, as in this video:

"SodaStream" cylinders are actually generic gas cylinders of a standard which is called "S30", so you need an S30 CO2 cylinder, not necessarily a SodaStream.

Besides capping the bottles, considering the relatively low cost I think I will put some CO2 inside the fermenter at yeast pitching time. CO2 will sit (given some time) on the beer making a "blanket" and isolating it from air (OK there will be some air in any case but the oxydation might be reduced). That might help against not just oxidation but also infection in the first crucial day of fermentation.
 
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Miraculix

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I went to one of those hardware store chains, Leroy Merlin. Similar chains in Italy are Bricofer, Obi and others. There you have to look for the soldering sector. You will find there cylinders with oxygen, or CO2, and also argon and argon-CO2 mix.

There are let's say three kinds of cylinders that you can buy.

The large and serious cylinder, heavy to transport, which is used e.g. by people kegging the beer, or for real work in apartment restructuring etc. Those are refillable cylinders. They are filled at a very high pressure and have specific "valves" (pression reducers).
This is an example: Bombola Co2 da 4Kg Nuova ForHome® Ricaricabile Con Valvola Residuale Certificata
They might be overkill if the purpose is only capping.

Then you have the smaller, non-refillable cylinders. In the case of Oxygen, they come in two formats: small, around 24 litres of expanded gas, they are very light when you take them in your hand they seem empty, and "larger", not in physical dimensions but in weight and capacity, they hold more than 200 litres of expanded gas, the cylinder itself weights 1200g. Both kinds use the same pression reducers I do believe.
The pression reducer is often termed simply "for non-refillable cylinders", or it is termed "M10x1"

This is one example, a "heavier" CO2 non-refillable cylinder: Bombola a gas co2 AWELCO 0.95 L. Prezzo online | Leroy Merlin
The connector is called "filetto europeo", European thread, because that's a standard for those kind of cylinders. Basically M10x1, European thread or "for non-refillable cylinders" will get you the right pression reducer.

Note, though, that oxygen cylinders (which can be used for wort oxygenation, with a 0,5 micron aeration stone) need a specific pressure reducer, which is marked as "oxygen".

Actually now that I think about it, M10x1 is the one for oxygen, and generic "for non refillable cylinders" is for generic gas. Maybe (I did not test it) the two threads are different. [EDIT: tested, the thread is the same]

In any case, the assistant will give you the right pression reducer for the CO2 cylinder and the right pression reducer for the O2 cylinder. These cylinders typically are not sent by courier for the danger of explosion when left in hot temperatures, so you'll have to go to the hardware store.

Examples: Riduttore di pressione. Prezzo online | Leroy Merlin

The gas gets out through a "hose connector", you can couple there, typically, a hose with 3mm internal diameter. I bought this on Amazon.


A silicon hose is very good because you can immerse it with the aeration stone in a vessel with water and sanitize, or even sterilize it with a microwave oven without having to touch the stone to fit the hose again, you just sanitize all together.

Oxygen is easily inflammable and CO2 can suffocate you and actually kill you, so this stuff is to be kept with some caution. I keep the cylinders outside but NOT in direct sunlight, that creates a danger of explosion.

In order to use them, you just close the tap on the reducer, fill the reducer on the cylinder, and then open the tap for the gas to get out. No particular manoeuvers.

The cylinder does not stand right by itself so I will use a bottle-holder to keep it up. One hand manovrates the gas tap, the other keeps the silicon hose inside the bottle. I will report here how it worked.

Just as we are there, this is an oxygen cylinder:

That's, again, more than 200 litres of oxygen. If you oxygenate beer (at pitching stage) with 1 minute at 1 litre/minute of flow, you have more than 200 batches of beer for this cost (plus the cost of the pressure reducer).

Oxygen for "soldering" is basically identical to the one used for medical purposes, for our goals. You will find very pure gases in there, no oils or other unwanted stuff.

Another option is to use the SodaStream cylinders with an adapter, as in this video:

"SodaStream" cylinders are actually generic gas cylinders of a standard which is called "S30", so you need an S30 CO2 cylinder, not necessarily a SodaStream.

Besides capping the bottles, considering the relatively low cost I think I will put some CO2 inside the fermenter at yeast pitching time. CO2 will sit (given some time) on the beer making a "blanket" and isolating it from air (OK there will be some air in any case but the oxydation might be reduced). That might help against not just oxidation but also infection in the first crucial day of fermentation.
Wow, thank you, great information!!!
 

Vale71

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You don't seem to be much into wine.
Natural cork is quite permeable to oxygen...
No it isn't, look it up.

Wax is not a barrier against counterfeiting: it's extremely easy to use (just like the fascette). You see that in the video. That sort of "rubber stamp" which is used to impress a trademark on the wax is also very easy to counterfeit, much more than the label which you have to counterfeit in any case.
Which is why today it's just for looks (a.k.a. marketing)

Your approach is too much science and not enough life. Just ask any proper winery why the capsules are perforated and they will let you that it is to let a minimum of gas exchange. The capsule would not be sufficiently gas-permeable. If you go to any good wine-shop and examine the bottles, you will see that all (and I mean all) wine capsules are perforated for this reason. Look well, the holes are tiny, but they are always there.
OK, so you're one of those people who think they "know better" when it's clear that you don't know anything. Good luck with that.

What I "claim" is demonstrated by "empirical evidence" which is in front of our eyes every day. If you search around the internet, you will find people who wax Belgian beer destined to long aging because crown caps are not reliable enough, and they will tell you that, in their experience, this solved the problem of crown tap leakage. And why should I not trust them? Because I went up looking on the internet the gas-permeability of wax just to contradict them? I am sure they are reliable because they talk through real-life experience and not abstract theory.
Your "empirical evidence" is just other peope believing the same nonsense you choose to believe. That is not evidence, if anything it's the opposite. The "abstract theory" you choose to ignore on the other hand is supported by sound, repeatable, scientific experiments.

IMHO you have a wrong approach to problem-solving, too analytical. I prefer to start from the experience of people solving problems, not from equations and physical properties. You are obviously free to ignore the experience of experienced people, and to go on having leaking crown caps or storing bottles into CO2-filled kegs, of course. But I do bet that, when you begin storing Belgian ales for a couple years, you will give a try to wax :)
Those "experienced people" will also tell you to bottle wine only during a full moon. Need I say more? I don't think so, that speaks for itself.
 
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Another option is to use the SodaStream cylinders with an adapter, as in this video:
Thanks for the infos. Without having the time to delve into it much deeper for the moment, I really like the Soda Stream cylinder idea. I'll have to find out how or where to get one of those adapters here.
It seems to me that you could easily rig it up as to handle the cylinder and valve with one hand, and the bottles/caps with the other.
 
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So I have a question for the experts on gas physics here (maybe a stupid one, or one that has already been answered X-times in this forum before…apologies if that’s the case).

If we assume, like it is often stated here and elsewhere, that bottle caps do not seal 100% airtight, and that some albeit very reduced rate of gas exchange will still be happening… then why is there no significant carbonation loss in beer over a long aging period?

The partial CO2 pressure inside a bottle of beer is of an order of magnitudes higher than the partial CO2 pressure in the air. As a consequence, shouldn’t the CO2 be able to gradually escape the bottle?


Is it because those seals are only permeable to O2, but not to CO2?


Same for PET: Is this material permeable to O2, but on the other hand very effective at blocking CO2? Otherwise I’d guess that one should notice some carbonation loss over time in soda drinks stored in PET?
 

Vale71

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If we assume, like it is often stated here and elsewhere, that bottle caps do not seal 100% airtight, and that some albeit very reduced rate of gas exchange will still be happening… then why is there no significant carbonation loss in beer over a long aging period?
That's because there is an actual loss of carbonation but it will take a really long time (like several years) for it to become noticeable. That is, if it becomes noticeable at all. If there is any further fermentation, either because of an infection or because the beer is not pasteurized and there is some residual fermentable extract, this might more than compensate for the loss of carbonation.
Same goes for PET bottles, there is some loss but since nobody will store soda drinks for, say, 5+ years, which would be well past any "best before" date, this doesn't get noticed in practice.
 

Birrofilo

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No it isn't, look it up.
No it definitely and absolutely is.
The "cork" market is divided into several products, all of which have their own gaspermeability.
Wine makers do experiment with the effect different corks have on the same wine batch.
All corks, include natural "monopiece" corks, have a gaspermeability, which is necessary.

"Silicon" corks also have gaspermeability, and actually they are considered unsafe for wine to be laid down because they have too much of it. You find them on wine which is to be drunk young (even of very good quality).

Now obviously if you go and search "silicon" you might find "silicon has no gaspermeability", again your approach is flawed, you over-think things and don't consider facts of real life.

Google is your friend in translating this test with 6 different corks on the same batch of wine


Wine-making is very serious stuff, and there is not less science in it than in beer making. People is not stupid, they use cork for a reason.
 
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Taket_al_Tauro

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That's because there is an actual loss of carbonation but it will take a really long time (like several years) for it to become noticeable. That is, if it becomes noticeable at all. If there is any further fermentation, either because of an infection or because the beer is not pasteurized and there is some residual fermentable extract, this might more than compensate for the loss of carbonation.
Same goes for PET bottles, there is some loss but since nobody will store soda drinks for, say, 5+ years, which would be long past any "best before" date, this doesn't get noticed in practice.
Thanks, makes sense.
I might try to keep one mineral water or soda bottle in my cellar and come back here in 10-20 years to report my observations ;)
 

Birrofilo

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If we assume, like it is often stated here and elsewhere, that bottle caps do not seal 100% airtight, and that some albeit very reduced rate of gas exchange will still be happening… then why is there no significant carbonation loss in beer over a long aging period?
I think this might have to do with an increased pressure inside the bottle. If you had a leakage in the gasket of the tap of your fermenter, you might have noticed that the leakage might be very tiny (a drop now and then) or that it only happens at a certain "level" of beer or water (and not for a lower level).

What might happen is that the continuous fermentation (fermentation inside the bottle never stops, if you give it time yeast might consume complex sugars that they don't consume during the normal fermentation) creates an extra pressure inside the bottle.
This extra pressure will deformate the crown cap and I see two possible scenarios:
a) The tap "burps" elastically and then reacquires its shape perfectly and goes on doing its job;
b) The tap "burps" and remain deformed (we are talking very tiny gaps) and there will be some loss of pressure. Yet, at a lower pressure level, the gas escaping should stop because at that pressure level the cap is still tight enough.

But I would not rule out the other case: a continuous infinetely small leakage, as would be a drop every half an hour in a fermenter gasket. Given enough time, that will be a noticeable leakage.

If only the first case applies, then a stabilized bottle of beer should retain its pressure forever (because there is no biological activity inside).

If the second case applies, even a stabilized bottle of beer could lose pressure, given enough time. Actually it will lose pressure in a more noticeable way because there is no creation of new CO2 inside the bottle.

We have to keep in mind that there are no gaskets involved, gaskets solve the problem of a less than perfect adherence between two surfaces by deforming themselves, in a crown cap glass and metal should adhere absolutely perfectly for gas not being able to escape and one cannot rule out manufacturing imperfections in glass and metal so that there is a little, microscopic but continuous leakage happening at every moment, and that becomes noticeable only in long-term storage.

Thinking about it that appears to me the most likely case: a continuous leakage which becomes noticeable only after a long time.

Beer for long storage is also sold with corks, because they allow the fermentation gases to escape (just like in corks for wine) when there is some internal pressure, while keeping an overall tight barrier to external air.

If crown caps were perfectly air-tight, there would be no need to use corks for beer sold for aging (Chimay Grande Reserve comes to mind. You are supposed to want to lay that down for some years, the taste will change. The 33cl bottle is sold with crown cap, the 75cl bottle is sold with a cork, and that's the one you are supposed to lay down).
 
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Vale71

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No it definitely and absolutely is.
The "cork" market is divided into several products, all of which have their own gaspermeability.
Wine makers do experiment with the effect different corks have on the same wine batch.
All corks, include natural "monopiece" corks, have a gaspermeability, which is necessary.

"Silicon" corks also have gaspermeability, and actually they are considered unsafe for wine to be laid down because they have too much of it. You find them on wine which is to be drunk young (even of very good quality).

Now obviously if you go and search "silicon" you might find "silicon has no gaspermeability", again your approach is flawed, you over-think things and don't consider facts of real life.

Google is your friend in translating this test with 6 different corks on the same batch of wine


Wine-making is very serious stuff, and there is not less science in it than in beer making. People is not stupid, they use cork for a reason.
Here it's a much more reputable source of information than a bunch of tinkerers sitting around a table drinking wine.


So called "oxygen ingress" using natural corks is actually the air trapped into the material being released into the bottle with time. If the corks were somehow purged of that air prior to capping (not practical) you'd have zero oxygen ingress.

Incidentally, it's silicone and FYI I'm very well aware of its gas permeability characteristics as forum members who know me well can attest. If you'd like I can calculate for you how much O2 is entering your fermenter (and somehow not flying away...) through a silicone blow-off hose of a given size and material thickness.

Yes, people is not stupid (but their grammar might me lacking...) but more often than not they do something simply because they don't know better.
 

Vale71

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What might happen is that the continuous fermentation (fermentation inside the bottle never stops, if you give it time yeast might consume complex sugars that they don't consume during the normal fermentation) creates an extra pressure inside the bottle.
That's nonsense. Barring an actual infection yeast will not magically acquire the power to ferment anything beyond maltotriose.

Loss of gas thorugh a gas permeable barrier happens through continuous diffusion (into, through and out of the barrier) and there is no "burping" or other such nonsense. You don't need any "gaps" as the gaps between the polymer chains in the material already let through gases through diffusion.
 

Birrofilo

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That's nonsense. Barring an actual infection yeast will not magically acquire the power to ferment anything beyond maltotriose.

Loss of gas thorugh a gas permeable barrier happens through continuous diffusion (into, through and out of the barrier) and there is no "burping" or other such nonsense. You don't need any "gaps" as the gaps between the polymer chains in the material already let through gases through diffusion.
That's again nonsense. Read people who know, such as White and others. Do your homework.
Saying that a yeast "cannot" ferment complex sugars is a common and practical simplification.
Many yeast strains will do that, if you give them time.

The ordinary experience of homebrewers (who certainly don't let the beer in the fermenter for years) is that the yeast "stops" fermenting when certain sugars have been consumed. But the yeast is a living being which is always in search for food. You can digest a leather sole, if you chew enough!

You think that you cannot digest soles, because you never tried.
You think that yeast will never make use of complex sugars, because you never let your beer ferment for years, or your bottle age for years.

If you don't stabilize a fermentation, ANY fermentation, that will go on and on, adapting to the new conditions. The Ancient Romans fermented Garum for several years. Japanese ferment Umeboshi for years. This means that food undergoes several stages of fermentation. Bacteria adapt to the food they have.

When a wine is left to age for years, what happens inside is also fermentation.

In a Lambic you have all sorts of fermentations going on for years.

The same can be said for old Port, Marsala, Sherry, Madeira etc. and also for preparations like Aceto Balsamico Tradizionale di Modena DOP (you can buy that aged for "at least 25 years", each new stage of fermentation adds a layer of aromatic complexity).

Also your idea of "infection" is simplified. What you call "infection" other call "aging". There are other microbes, in your beer, which - given time - will do their own fermentation and will add to the complexity of the aroma (if things go well) or spoil the bottle (if things go bad). That "infection" is an important costituent of "aging" for wines and beers (the case of the Belgian Lambic being paramount, because in those cases, for what I read, there is more "infection" than beer...).
 
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Vale71

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You clearly have absolutely no idea what you're talking about. It was already clear from all your previous posts but still you keep piling on...
 

Birrofilo

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You clearly have absolutely no idea what you're talking about. It was already clear from all your previous posts but still you keep piling on...
Man, I insist it's you who have no idea what you are talking about, but have no humility to consider this hypothesis. I live it here.

EDIT I read your reference: it says: " Results for the natural cork showed diffusion of oxygen at a slow but continuous rate over the first 12 months of storage and in very tiny amounts through the cork−glass interface in the 12 monthsthereafter. "

It's this "very tiny amounts" which makes the difference. Cork is gas-permeable at least in its contact surface with glass and this is important, if you consider the long-term storage, which requires a "very tiny amount" of gas exchange.
Silicon is more gas-permeable because its pressure along the sides of the glass diminishes with time (it shrinks).

But also, your text says that the oxygen intake is "primarly" through diffusion, it doesn't exclude permeation, and it recognizes that there is some permeation, so much so that it says there is an interest now for screw-caps which can allow some permeation (i.e. "like cork").

And now that I think about it, cork is used in construction because it is a thermic isolant which allows some gas exchange, limiting molds and condensation (I don't know whether this is marketing b*****, but it is certainly sold as permeable to air, vapour etc.).
 
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Miraculix

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Hopefully I won't have to regret it.



That's not how gas diffusion through membranes work. Even if you have a multi-layered membrane the rate will only be limited by the layer with the least permeability.

Let's try to explain using an analogy with water and funnels. Let's say you have water running through a system of funnels connected serially. One funnel has a throughput of 10 liters per minute and this funnel cannot be exchanged for a different funnel and all the water has to pass through this funnel. This funnel cleraly represents our crown cap. Let's say that you can now place a second funnel before this funnel and you can choose between a funnel that has a throughput of 1000 liters per minute and one that only lets 20 liters per minute through but keep in mind that all water still has to pass through the first funnel that has a 10 liters per minute rate. Which combination of funnels will give the highest total throughput? There is only one correct answer of course. ;)
I think your example is not suitable, as we have quite a different situation here then direct flow of water but gas diffusing through a membrane.

Let's say it like this, if you got a membrane, that, under given circumstances, lets 10% of what is on the one side of the membrane to the other side, and you double that up with another membrane, which again let's only 10% pass, you'll end up with a total permeability of one percent as 10% of 10% is one percent. This is the situation we got here. Two limiting membranes, the wax and the crown cap, one after the other.
 
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McKnuckle

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What could be intelligent and revealing discourse/debate is sadly forced to devolve into "I'm always right, and you're an idiot." Nobody is always right, and while there are certainly idiots, I don't see any of those here, especially not when writing about science in a second language.

The best teachers not only share their knowledge freely and without resentment, they also learn from their students. And we are all both teachers and students.

Now, I suggest to go put a cork in it!
 

Vale71

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I think your example is not suitable, as we have quite a different situation here then direct flow of water but gas diffusing through a membrane.

Let's say it like this, of you got a membrane, that, under given circumstances, lets 10% of what is on the one side of the membrane to the other side, and you double that up with another membrane, which again let's only 10% pass, you'll end up with a total permeability of one percent as 10% of 10% is one percent. Thus is the situation we got here. Two limiting membranes, the wax and the crown cap, one after the other.
Gas permeation doesn't work like that, sorry. Since we're talking about flow-rates you can't measure those in "percent". In your example, what's "10% of what is on the one side" in terms of mass flow units?? As a matter of fact, what is this thing that's to be found "on the other side"? Granted, permeability is a function of thickness (an inverse function) so any material if deposited in a thick enough layer could reduce permeability. The problem is, with a highly permeable material you'll need an exceptionally thick layer and that's often impractical, so that one is forced to look for better materials with low permeability coefficient. Nowadays this means synthetic materials.
 

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Gas permeation doesn't work like that, sorry. Since we're talking about flow-rates you can't measure those in "percent". In your example, what's "10% of what is on the one side" in terms of mass flow units?? As a matter of fact, what is this thing that's to be found "on the other side"? Granted, permeability is a function of thickness (an inverse function) so any material if deposited in a thick enough layer could reduce permeability. The problem is, with a highly permeable material you'll need an exceptionally thick layer and that's often impractical, so that one is forced to look for better materials with low permeability coefficient. Nowadays this means synthetic materials.
I think you might have a model in your head that works well when gas mixes with gas but not when gas has to permeate a physical barrier. With a barrier it is quite simple, the thicker the barrier, the less gas gets through over a defined time. We are adding another layer, so the resistance for the gas increases.
 
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