Some call the O2 absorbing. Do they do anything other than drain your wallet slightly faster?
I couldn’t swear they work, but I’m willing to pay more for them for beers that are going to be aged a long time. Couldn’t hurt.
Ditto here. I’ve used them for years.
Where I buy them, they are only $1 more per bag. All I can say is that last year I opened a bottle of Wee Heavy that I made in the early 1990’s, and there was no hint of oxidation in the palate (or if there was, it was certainly below my taste threshold as well as the two people I shared the brew with).
For the extra buck, to me it’s a no-brainer.
The standard caps go on the run of the mill beers that are not for aging. Big beers, cides and meads get the O2 barrier caps.
I’ve heard that Sierra Nevada changed their bottles from screw off caps to pry off caps just so theycould switch to O2 absorbing caps. Those guys know their sh*t.
I thought it was a new plastic that had 1/20th of the O2 getting in over time. There was a little said about it in the 2009 keynote at the NHC, and a graph. You can download it here, it is a little big.
http://www.ahaconference.org/past-presentations/2009-presentations/
In my fuzzy memory, I remember someone saying they switched to pry offs (with the plastic barrier caps), then to o2 scavenging caps, and then switching back to the barrier caps because the o2 scavenging caps had no effect or a negative effect.
I ended up buying them because it was all my LHBS had at the time and well I needed caps to bottle. It seemed to me the beer was fully conditioned in less time, however I am not sold on my own theory.