Oxygen permeability of HDPE

[gatewood]

I've decided to begin using some leftover HDPE (number 2 plastic) to make bigger alcohol batches. However, I've been aware for some time that PET, HDPE and LDPE are watertight but permeable to oxygen (introducing unwanted aeration into the vessel), and I usually lose some sugar, being converted into CO2, when using PET bottles.

The buckets are about 2mm thick and pretty rigid, you guys think this sufficient to make them suitable vessels?

 

[day_trippr]

I know there are more comprehensive tables than this one (though I'm not finding one now) but this one covers the relative barrier properties between HDPE and PET, the latter being a bit more than an order of magnitude better at blocking O2.

I'd stick with PET if possible...

Cheers!

 

[gatewood]

I know there are more comprehensive tables than this one (though I'm not finding one now) but this one covers the relative barrier properties between HDPE and PET, the latter being a bit more than an order of magnitude better at blocking O2.

View attachment 707967

I'd stick with PET if possible...

Cheers!

damn, I was completely unaware of such measurements, most appreciated input

Btw, I was thinking that, maybe, I could also paint the buckets to add another layer that oxygen has to go through (like we do with metals).

 

[tracer bullet]

Bumping a not super-old thread. I was looking into a blow-off hose that wasn't silicone, thinking that it'd be yet one more step towards removing oxygen from my fermented beer. I use Big Mouth Bubblers, which are PET, so that's good to see they're almost at the bottom of the list (not to be confused with LDPE and HDPE). I didn't see silicone on this list but found it on another, and yeah it's pretty bad. I'll link that below. It's not an exact apples / apples comparison here but you can see the relative ranking of some different materials with some of them crossing with the chart @day_trippr posted earlier.

I think I'll be looking for some 1/2" PET blow-off tubing.

Scroll down to page 4 if interested:

https://imageserv5.team-logic.com/mediaLibrary/99/D116_20Haibing_20Zhang_20et_20al.pdf