Bottle Cap Preference

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NTXBrauer

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I normally use whatever is available at my LHBS when buying bottle caps, but understand the oxygen absorbing ones are recommended for lengthy bottling times (1 yr+). What do you your thoughts on this?
 
I think it comes down to your brew and bottle process with how fast you drink your beer. If you have no off flavors to age out and bottle cleanly (not oxygenating the beer) you probably are good with standard caps.

The LHBS I normally go to only sells the oxygen absorbing caps. Their reasoning is no need to track 2 types of caps and their mark up is the same on both.
 
I haven't yet noticed any difference, but seldom have I bottle aged a beer past 6 months. :)
 
oxygen caps can have a hop aroma robbing quality when used with IPA's, from my experience. I use oxygen caps on all my beers except the highly hopped ones.
 
Does anyone have any evidence that they do anything at all?

I would think the amount of oxygen they could absorb would be minuscule.

Absent facts, it smells like a clever marketing scam.
 
I am wondering how they absorb oxygen and to what degree/ timeline. The bag does not seem hermetically sealed so right of the shelf they have been exposed to oxygen.

Haven't noticed hop robbing quality but I don't make a lot of IPA.
 
think they're liquid-activated or something like that

which is why you don't boil to sanitize them.

I haven't searched for a side-by-side comparison to regular caps for long-term storage or aroma-stealing properties
 
I am wondering how they absorb oxygen and to what degree/ timeline. The bag does not seem hermetically sealed so right of the shelf they have been exposed to oxygen.

Haven't noticed hop robbing quality but I don't make a lot of IPA.

I've only used them once or twice, but I do generally know how they work. They contain pure iron (or a similar metal), probably in rather small particles, embedded in a membrane. The basic principle is that when exposed to oxygen, the pure (zero state) iron will oxidize to form an iron oxide (with a higher valence state). This consumes oxygen and "traps" it in the metal.

They aren't "activated" until you wet them, my guess is there's some type of very thin water-soluble layer that dissolves away and exposes the metal particles to the air in the headspace. The reaction happens on the order of hours, so wetting the caps via a dunk in Star San right before you bottle will not negate the oxygen-absorbing properties.

Iron (and other metals) give off a tiny bit of heat as they oxidize, and this is how chemical hand warmers work. When you open the bag, you expose the iron powder to the air. As the iron slowly oxidizes, it produces heat.

The science behind the caps is pretty basic, but I don't know if it the result is anything noticeable.
 
I've only used them once or twice, but I do generally know how they work. They contain pure iron (or a similar metal), probably in rather small particles, embedded in a membrane. The basic principle is that when exposed to oxygen, the pure (zero state) iron will oxidize to form an iron oxide (with a higher valence state). This consumes oxygen and "traps" it in the metal.

They aren't "activated" until you wet them, my guess is there's some type of very thin water-soluble layer that dissolves away and exposes the metal particles to the air in the headspace. The reaction happens on the order of hours, so wetting the caps via a dunk in Star San right before you bottle will not negate the oxygen-absorbing properties.

Iron (and other metals) give off a tiny bit of heat as they oxidize, and this is how chemical hand warmers work. When you open the bag, you expose the iron powder to the air. As the iron slowly oxidizes, it produces heat.

The science behind the caps is pretty basic, but I don't know if it the result is anything noticeable.

better explanation than I could give

boomy.jpg
 
I've only used them once or twice, but I do generally know how they work. They contain pure iron (or a similar metal), probably in rather small particles, embedded in a membrane. The basic principle is that when exposed to oxygen, the pure (zero state) iron will oxidize to form an iron oxide (with a higher valence state). This consumes oxygen and "traps" it in the metal.

They aren't "activated" until you wet them, my guess is there's some type of very thin water-soluble layer that dissolves away and exposes the metal particles to the air in the headspace. The reaction happens on the order of hours, so wetting the caps via a dunk in Star San right before you bottle will not negate the oxygen-absorbing properties.

Iron (and other metals) give off a tiny bit of heat as they oxidize, and this is how chemical hand warmers work. When you open the bag, you expose the iron powder to the air. As the iron slowly oxidizes, it produces heat.

The science behind the caps is pretty basic, but I don't know if it the result is anything noticeable.

Thanks zachattack for the detailed response! :mug:
 
The science behind the caps is pretty basic, but I don't know if it the result is anything noticeable.

Yeah- it's not as though they can save an already oxidized beer. Thanks for the awesome explanation btw. :mug:

Until recently I had been using the oxy scavengers but I doubt I'll spend any more money on them in the future.

I'll try a side by side comparison when I bottle my imperial stout. It will be a while before I notice anything I am sure.

Maybe it would be worth trying this with an IPA to see if they really absorb hop flavor/ aromas as well.
 
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