Back to Shopping at

Caps - O2 absorbing or regular?

I notice that in several brewing supply sources I am offered a choice between oxygen absorbing caps or regular caps (I assume they are just regular).

Which is better? The cost doesn’t seem that much more for the O2 ones.

I’m using nthe O2 absorbing caps right now, can’t tell any difference quite frankly.

It’s a personal preference but here is what it boils down to.

02 absorbing caps will not work if they are dipped in sanitizer. The chemicals in the sanitizer does something to the O2 absorbing barrier, rendering it useless. If you want the barrier to work the caps have to be dipped in clean water first.

The caps will be fine if they dipped in sanitizer. They will just act like normal caps.

If you have to bottle condition for a year a more then O2 absorbing will give the biggest benefit so your beer does not oxidize. If you plan on bottle condition for less than a year it doesn’t matter which cap you use.

They’ll contact beer, I don’t see the need to pre-rinse them.

I just do it to keep any dust or debris out of the beer. Not really worried about infection at this point but just to keep piece of mind.

But if you want to active the O2 absorbing barrier you have to dip it in water first.

I don’t think I’ll be bottling anything for up to a year so I should be fine with normal ones.

The oxygen barrier caps can be rendered less-useful if you dip them in an oxygen (peroxide) type sanitizer, but StarSan doesn’t do anything to them other than sanitize. I drop enough caps for the entire batch into a bowl of StarSan, fill five or six bottles, then set a wet cap on top of each bottle and continue filling and setting caps until the batch is done. Then I start capping from the first filled to the last. The loose cap allows the CO2 coming out of the beer to push the O2 out of the bottle, or at least dilute it a bit, and once the bottle is sealed the cap starts scavenging the oxygen.

For the extra buck or two, I always get the o2 caps. I make enough beer which is specifically designed to stay in the bottle for a year (or considerably longer) that I see no point in keeping both types of cap on hand. The difference in cost is negligible.

Back to Shopping at