Oxygen Absorbing Caps

[JonnyAnchovy]

Hi All,

I'm interested in hearing people's opinions on the oxgen-eating bottle caps on the market - who used them? Any noticeable difference in shelf-life?

Extra points for first-hand experience.

 

[peas_and_corn]

I've never used them, but I really don't store beer for a long time.

 

[Fourstar]

AFAIK Sierra Nevada have recently begain using them.

Anything to reduce oxidation especially with shipping your beer all over the universe is a good thing. They may also help the homebrewer who stores their beer in enviroments where the temperature can fluctuate quite a bit as O2 can be drawn in under the cap when this happens.

 

[MHB]

There are two answers and they are both right
If you are packaging Filtered/Pasteurised that is to say sterile beer they are a great idea.
If your beer has live yeast they are a complete WOFTAM, the yeast will do a better job of scavenging any O₂ than the caps ever will
As my beer has live yeast Bah! Hocus Pocus nonsence!

AFAIK Sierra Nevada have recently begain using them.

Anything to reduce oxidation especially with shipping your beer all over the universe is a good thing. They may also help the homebrewer who stores their beer in enviroments where the temperature can fluctuate quite a bit as O2 can be drawn in under the cap when this happens.

Really, you must have interesting O₂ at your place, stuff with a special exemption to the laws of physics, I never have any problem with gas leaking into a pressurised container.

MHB

 

[bradsbrew]

I'll be using these after filling the bottles of my comp beers with my CPBF. Any other time I will be using normal caps.

Cheers

 

[Kai]

Really, you must have interesting O₂ at your place, stuff with a special exemption to the laws of physics, I never have any problem with gas leaking into a pressurised container.

MHB

Any plastic is a semi-permeable membrane and O2 can transfer in against the pressure gradient just as easily as CO2 in the beer can transfer out with it. I never did physics at high school and university is too dim and hazy a memory to properly explain it, but 'strue. Same as why PET bottles aren't as good for long term storage; the CO2 inside wants to equilibrate with outside, and the O2 wants to do the same with what's in the bottle. It just happens a lot slower through a bottle top.

But, Sierra Nevada don't use oxygen scavenging caps. They use barrier seals, which will not scavenge oxy already present in the bottle but do reduce O2 ingress via the plastic under the seal when compared to normal or scavenging caps.

At home, just like HSA, I don't think there's any point using oxygen scavenging caps unless you can guarantee low DO levels in every other point of your process. By my reckoning if your beer has had too much exposure to oxygen before you bottle then your beer will continue to oxidise in the bottle regardless of what type of crown seal you use.

 

[tallie]

I bought some of these recently for a Barley Wine that I'm planning on bottling and putting away for a few years.

Upon reading the replies above, I'm starting to wonder if it's worth it. Now I'm thinking of capping a couple of bottles with regular caps and trying them side-by-side in a few years time to see if there's any difference between the two.

Check back here in a couple of years and I'll let you know how it goes

Cheers,
Kris.

 

[zoidbergmerc]

where the temperature can fluctuate quite a bit as O2 can be drawn in under the cap when this happens.

and fourstar's credibility does down, way way way down.

Seriously? Air from the outside of a pressurised bottle getting into said pressurised bottle?

 

[Kai]

and fourstar's credibility does down, way way way down.

Seriously? Air from the outside of a pressurised bottle getting into said pressurised bottle?

Not air, oxygen. Though temperature fluctuations have nothing to do with it.

 

[///]

Father-in-Law worked on the polymer for the oxygen scavenging caps in the late 70's (or was it 80's?) as an industrial chem with ICI .... can ask!

But, whats it matter with homebrew. Our left over yeasties and a bit of sugar are better than most a sucking up that oxygen!

Scotty

 

[zoidbergmerc]

Not air, oxygen. Though temperature fluctuations have nothing to do with it.

Care to share on how pure O2 manages to get into my pressurised beer bottles then?

 

[thelastspud]

yeah i thought positive pressure would keep o2 out, what happens? does a little bit leak out and that lets a little bit in?

 

[Fourstar]

Im not going to go into depth about it as i dont know the science behind it. I heard/read about them some time ago, something todo with vacuum and temperature differentials of ambient and the contents of the bottle. I'd highly doubt the draw of O2 would be anything signifigant but for long term storage (including low O2 exposure up until bottling) they could be a good thing.

Thinking about it, i think it might have been during a Q&A with Charlie Bamforth although i cannot confirm. Heck i may even be confusing the use of vacuum to remove O2 during the bottling process before capping. But i definitly can remember something todo with temperature differentials and oxygen eating caps.

 

[JonnyAnchovy]

lol @ poll results.

 

[zoidbergmerc]

Im not going to go into depth about it as i dont know the science behind it. I heard/read about them some time ago, something todo with vacuum and temperature differentials of ambient and the contents of the bottle. I'd highly doubt the draw of O2 would be anything signifigant but for long term storage (including low O2 exposure up until bottling) they could be a good thing.

Thinking about it, i think it might have been during a Q&A with Charlie Bamforth although i cannot confirm. Heck i may even be confusing the use of vacuum to remove O2 during the bottling process before capping. But i definitly can remember something todo with temperature differentials and oxygen eating caps.

i think you must be very very confused if you think just O2, not Air, not Nitrogen (which is smaller than Oxygen), just O2 entering a pressurised vessel.

 

[JestersDarts]

Just popped over to DrKarls science forum and asked the quick question about oxygen permeating through the PET into the pressurised solution -

From the answer I got back , it seems as though any oxygen in the solution can be at a different pressure than the other elements, and permeate out or in the bottle accordingly.

Although this process would be extremely slow.

 

[Kai]

Care to share on how pure O2 manages to get into my pressurised beer bottles then?

I shared what I knew earlier in the thread.

Come to think of it, first year biology covered the concept too. Look up osmosis and diffusion.

 

[zoidbergmerc]

I'm familiar with osmosis and diffusion but they just wont happen when the pressure in the bottle is much higher than the pressure outside the bottle. Look up Physics. All the pressure from the bottle would have to be released before anything else from the outside can get in.

 

[felten]

Thinking about it, i think it might have been during a Q&A with Charlie Bamforth although i cannot confirm. Heck i may even be confusing the use of vacuum to remove O2 during the bottling process before capping. But i definitly can remember something todo with temperature differentials and oxygen eating caps.

yah Charlie Bamforth on the Q and A 30-11-09 ep says "air will creep between the bottle and the cap". They also mention temp fluctuations pull in air under the caps, but they don't elaborate on the science of it unfortunately.

 

[Fourstar]

i think you must be very very confused if you think just O2, not Air, not Nitrogen (which is smaller than Oxygen), just O2 entering a pressurised vessel.

Errrr no, im not very confused. When did i say that? The topic is oxidation and the effect O2 has on beer stability. Not the effect of nitrogen, or the make up of our atmosphere on beer stability. Although im sure they could permeate into our beer with plenty of other things as well.

yah Charlie Bamforth on the Q and A 30-11-09 ep says "air will creep between the bottle and the cap". They also mention temp fluctuations pull in air under the caps, but they don't elaborate on the science of it unfortunately.

Yeah that must be it. Atleast somone has heard the same thing.