Oxygen absorbing caps

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jamesrtaft

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Pretty novice to brewing, about 6 batches deep, but I have a quick question. I am making an imperial stout that will age for about 8 months while me and 11 of my closest friends take a little vacation. Should I cap with oxygen absorbing caps because they will sit for that long in the bottle or are regular caps fine? Thanks in advance!
 
If you are bottle conditioning it will not matter, the yeast should take up what little oxygen is left in the bottle.
 
You will probably get two answers to this question: 1. Go ahead and use the O2 absorbing caps and 2. The O2 absorbing caps are not much better than the reqular caps you use. I got both of these answers several years ago and decided that bottle conditioning my RIS desevered the extra small amount of money to use the caps. Turned out just fine. When in doubt, be nice to your beer and it will nice to you.
 
The real question is how the hell are you going on an 8 month vacation. I'm jealous.

Amen to that. Please tell your secret.



But those caps make no sense.

Claiming something absorbs oxygen, Or specifically dioxygen (o2), and NOT carbon dioxide (co2) is physically impossible since co2 contains 02.

So either the manufacturers are making false claims, or they really do absorb o2. Which, if that's the case and they do indeed absorb O2, physics says that they must absorb co2 as well.

Furthermore. The small amount of o2 in the bottle will dissipate into the beer because of the pressure and be used by the yeast.

So, simply, the yeast will absorb more oxygen more effectively than any fancy cap will.
 
Amen to that. Please tell your secret.

But those caps make no sense.

Claiming something absorbs oxygen, Or specifically dioxygen (o2), and NOT carbon dioxide (co2) is physically impossible since co2 contains 02.

So either the manufacturers are making false claims, or they really do absorb o2. Which, if that's the case and they do indeed absorb O2, physics says that they must absorb co2 as well.

Furthermore. The small amount of o2 in the bottle will dissipate into the beer because of the pressure and be used by the yeast.

So, simply, the yeast will absorb more oxygen more effectively than any fancy cap will.

Co2 is simply not o2. Just like o3 isn't o2. If I recall high school chemistry correctly, the oxygen in co2 are on either side of the carbon molecule which means of something like an oxygen absorbing film was bonding with o2 molecules, the sheer size of the large carbon molecule could keep it from bonding.

I like using oxy caps because I've had a couple of cardboard beers before and I like the tiny added protection. Don't wet the caps for sanitizing btw because this activates them and you have seconds to absorb the o2. The yeast post fermentation aren't going to absorb oxygen btw, so don't count on that. They have to have the right environment for that stage of metabolism.
 
O3 is ozone.
O2 is dioxygen
O is oxygen.

If you remember high school chemistry correctly, then you will know that of the six types of reactions, a synthesis reaction is the one that's easily broken. (Which is what c+o2(2)--->co2 is)

It's impossible to absorb gaseous o2, and leave the co2 untouched.


Well I wouldn't say it's impossible, but I highly doubt a cap can do a differentiation decomposition. There's about as much chance of that as me growing an extra 8" down south.
 
Nope. The oxygen is bonded to the more complex carbon molecule The material under the plastic in the cap can't break that bond that easily. They can't nutralize mazons(sp?). But they do certainly work. Wetting them makes the chemical disc under the platic activate. I rather think that they also keep air leaking in from getting to the beer. At any rate,my hoppy ales last a couple week more for about $1 more per bag of 144. I usually buy 2 bags. So 288 caps divided by 48 bottles per batch makes 6 batches before I need to buy more. So a buck more per bag is well worth it. And yes,I proved on my own they def work.
Oh,I almost forgot. They're called "oxygen barrier caps",not oxygen absorbing.
 
I think it was on that short lived series featuring Sam Caligone from Dogfish Head where the brewery ran an experiment on the O2 barrier caps and non-barrier caps and the barrier caps were slightly better but not worth the expense they would've had to spend for their enormous batches. For the homebrewer it is probably worth the few extra cents or whatever it is though if you are going to age something longer than 6 months.
 
My thoughts as well. But hoppy beers seem to retain there hop qualities a couple weeks longer in my observations. As long as mine last after 2 months work...:cross:
 
We had this discussion in one of the forums down below. What I do with them now is count out enough for the average number of bottles I know I can get. Then dunk the in starsan before placing on the bottle. I figured this would save the o2 barrier disc from going nutral before they're crimped. I get 8-12 bottles filled then crimp the caps. I then invert the bottle twice bfore placing in the box.
 
Anybody know if you can sanitize oxygen scavenging caps in star San and not ruin the oxygen absorbing capability?

I'm not sure on the science behind it but I have aged a beer for 2 years and my caps were certainly soaked in StarSan and the beer was only marginally oxidized as in the first sip had that oxidized flavor but after it warmed up and "breathed" the off-flavor dissipated.
 
that's one of the things I changed about sanitizing the o2 barrier caps. Just a quick dunk in starsan rather than soking seems to keep the o2 barrier disc from nutralizing from soaking too long.
 
I have to hold my opinion until I see any imperical data on their functionality.

But given the physics behind it, I have to call bs.
 
O3 is ozone.
O2 is dioxygen
O is oxygen.

If you remember high school chemistry correctly, then you will know that of the six types of reactions, a synthesis reaction is the one that's easily broken. (Which is what c+o2(2)--->co2 is)

It's impossible to absorb gaseous o2, and leave the co2 untouched.


Well I wouldn't say it's impossible, but I highly doubt a cap can do a differentiation decomposition. There's about as much chance of that as me growing an extra 8" down south.

That must have been an absolutely fascinating science class. Perhaps as taught by an english or geography major.

Oxygen absorbing caps contain a material (likely iron or another metal) held in a resin behind a membrane which is permeable to oxygen, but not to the oxides of whatever material are held in the resin. When wetted the material oxidizes, thus removing oxygen from the beer, drawing it across the membrane.

If you are bottle conditioning anyway, I would think that the yeast would take care of that anyway, although perhaps the caps do it a little more quickly, I'm not sure.

For a short lived beer they wouldn't make a difference but perhaps they can delay staling a little in a beer that's being put up a while. They aren't really expensive anyway, so why not I guess....
 
Well I'm not going to get into a pissing match over education.

So I'll bow out of this discussion.
 
I believe that the O2 absorbing caps took long enough to activate that soaking them in Star San didn't prematurely activate them as long as you used them in a reasonable amount of time. It only takes me about 20m to actually fill and cap a batch once setup. They should be ok in that time.
 
The guy at my LHBS today told me not to use the oxygen absorbing caps with hoppy beers because they absorb the hop aroma.
 
The guy at my LHBS today told me not to use the oxygen absorbing caps with hoppy beers because they absorb the hop aroma.

Although it is possible that some of the turpenes might adhere preferentially to the membrane of the cap, there is no way that they will cross the membrane nor will they react with the material that reacts with the oxygen.
 
The guy at my LHBS today told me not to use the oxygen absorbing caps with hoppy beers because they absorb the hop aroma.

This reminds me of a Mr. Wizard question in the October 2012 issue of BYO. Someone had asked why hoppy beers do not hold up well in bottles. He asked Dr. Peacock, an expert on hops, and go the answer that:

the polymeric liners used in bottle crowns to prevent oxygen ingress have a very strong affinity for aromatic hydrocarbons, just the sort of compounds associated with hoppy aromas....many of the most desirable aromas associated with hoppy brews are adsorbed by crown liners before most commercial beers ever make it into the consumer's glass

I think this a rather important point and I was surprised to not find a discussion of it here when the issue came out. It seems to me that if that was the case there would be a strong market for beer caps which were made of some other polymer that didn't adsorb hops!
 
I would not be jealous of my vacation, more of a business trip really.

Sounds to me like you're being deployed. If that's the case, thanks very much for your service and may God bless you and your unit.

Hope the brew turns out tasty.
 
So, when you use them, do you, fill the bottle, quick rinse the caps in starsan then cap right away? I didn't know you didn't want to soak them in starsan while bottling.... Bummer! Oh well live and learn I guess
 
I don't sanitize my oxygen absorbing caps. I also keep them sealed away to reduce potential nasties. Very little can survive in finished beer (anaerobic, alcohol, hop oils), and there is a strong yeast population. There are caps that are oxy barrier caps but some do absorb oxygen. The absorbing type of caps activate as soon as they get wet and stop absorbing quickly, so the only thing to absorb would be atmosphere. Alternatively, keggers can purge the bottles with co2 first to have the same effect.
 
Erroneous said:
I don't sanitize my oxygen absorbing caps. I also keep them sealed away to reduce potential nasties. Very little can survive in finished beer (anaerobic, alcohol, hop oils), and there is a strong yeast population. There are caps that are oxy barrier caps but some do absorb oxygen. The absorbing type of caps activate as soon as they get wet and stop absorbing quickly, so the only thing to absorb would be atmosphere. Alternatively, keggers can purge the bottles with co2 first to have the same effect.

So you mean to say its okay not to sanitizer them? Or is it that they come Pre- sanitizer anyway ? I intend to use them in my current brew!
 
So you mean to say its okay not to sanitizer them? Or is it that they come Pre- sanitizer anyway ? I intend to use them in my current brew!

I don't sanitize mine. There's threads discussing that issue. If you intend to use oxygen absorption caps then don't use a liquid sanitizer if you want them to work as intended, which would be hard tell. If you're worried about the tiny chance of infection in some bottles then there's always oven or UV sterilization.
 
I agree that unless you store your caps in chicken broth there is really no need to sanitize them.
 
The O2 absorption comes (as a previous poster indicated) from an easily oxidized material, such as iron, present in or under the membrane (Cichello, 2010). To suggest that it will strip O2 from CO2 ignores science. Then again we've only known about yeast's role in fermentation for 156 of the past 3,800 years, so superstition plays a large role in brewing it would seem.

Having judged a good many beers, I can attest to the strong correlation between large amounts of headspace and oxidized taste profiles. It is possible the lack of care exhibited by a sloppy fill is the precursor to the off taste and not the headspace itself, but in my experience a careful brewer makes a lot less bad beer than a sloppy one.

I have tasted a good number of beers capped with these and I have not noted any metallic notes which really would have been my only concern. If it makes people feel better, great. It does no harm, may do some good, and that's a lot better than you can say about some of the gimmicks out there. The science is there for the examination in the food packaging industry so I don't see why it's such a stretch to make the case (excuse the pun) for using it in beer packaging.

Cichello, Simon Ph.D. (2012). "A Guide to Oxygen Absorbers". Wholesale Group International Pty Ltd. Retrieved February 9, 2013 from OxygenAbsorbers.net.
 
A prominent member here did a little test with not sanitizing o2 barrier caps. It was something like 1 out of 3 got infected. So I've been doing a quick dunk & onto the bottle. Maybe not filling 12 or so before crimping them would be a hair better? I know from experience that they are an improvement. Just need to maybe improve the ol' process a bit.
 
A prominent member here did a little test with not sanitizing o2 barrier caps. It was something like 1 out of 3 got infected. So I've been doing a quick dunk & onto the bottle. Maybe not filling 12 or so before crimping them would be a hair better? I know from experience that they are an improvement. Just need to maybe improve the ol' process a bit.

That is interesting. My suspicion is that starsan will not prematurely trigger the caps. I think it is only the strong oxidizers like PBW or other percarbonate types that would ruin them. That said if you are worried about oxidation you are likely not using one step as a no-rinse :).
 
There is another thread here somewhere. Star san and iodophor are fine for these caps. Keep them away from one step. PBW and Oxyclean aren't sanitizers. If your caps are dirty I think you should probably get a special cap cleaning brush,
. The are made from synthetic fibers. Avoid the natural fiber brushes, can harbor micro organisms. Doh.. JK if your caps are dirty don't use Them...
 
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