Back to Shopping at

Oxy absorbing / Oxy barrier bottle caps?

Can someone tell me what the difference is if any between oxygen absorbing bottle caps and oxygen barrier bottle caps and if it really matters. I cant seem to find the answer in researching this. I’ve been using what is marketed as oxy barrier and its been fine. Just wondering if there is a difference.

Oxygen-absorbing caps have an internal liner that once activated by water, will absorb oxygen in the headspace of the bottle. Really good idea to use these with hoppy beers and anything that you want to age for some amount of time. Oxygen barrier caps are just bottle caps trying to confuse you with oxygen-absorbing caps. They’re nothing special, just regular bottle caps. They all block oxygen.

1 Like

Thanks for the explanation. So what I read is that you then really shouldn’t sanitize the oxygen absorbing caps with starsan as this will ruin the capability of the oxygen absorbing function. What is your opinion on this? Have you noticed a difference in using them? My local brew shop doesn’t carry oxygen absorbing caps and when asked about it he didn’t know the difference.

No, you should still sanitize them - it takes quite a bit of time for them to work, so the few minutes they’re in star-san won’t make much difference. It does activate them, though, so if you have any left-over caps, they won’t be effective if you dry them out and re-use them. At that point they’re basically just an oxygen barrier cap.

I haven’t done a back-to-back test with absorbing versus barrier caps, but my confirmation-biased opinion is that my hoppy beers seem to hold their aroma and flavor longer when using them.

I bought some oxygen absorbing caps my last trip to the brew store to test them out. I’ll be brewing a Speckled Heifer soon. I plan to save two bottles with the oxygen absorbing caps and two bottles with regular caps for three to four months. Just curious if the caps make a noticeable difference.

I’ll sanitize the oxygen barrier caps with a 30 second dip in Star San solution.

Awesome. Thanks guys

Back to Shopping at