Pet Bottles Not So Good For Storage

[white.grant]

Interesting fragment of information on smh.com about PET bottles being used for wine and increasing oxidation. I imagine it's probably similar for homebrew. The actual report is here.

cheers

grant

 

[Goofinder]

Seems to match up with what I've read on here before - that beer in PET bottles goes downhill after about 8-9 months.

If you're drinking it earlier than that you shouldn't have a problem. I used PET pretty much exclusively until I got my keg setup and never had any issues, though my beer was generally all gone by the 4 month mark. Glass is obviously better for longer term storage and is what I use for bigger beers for aging.

 

[Goofinder]

So it looks like they were specifically looking at those small single serve bottles. In this case I reckon the advantages of PET (smaller, lighter, more recyclable) would have to outweigh glass since you're obviously not after a fine wine experience in this situation. They just need to make sure they have supply and demand sorted out so they don't get too much excess lying around for more than 8 months.

 

[ianh]

Interesting article but storing wine and beer are totally different.

Wine is stored at normal atmospheric pressure using SO2 as preservative. Beer is stored at pressure due to the CO2 produced during carbonation.

Thus with wine oxygen slowly permeates through the PET bottle and reacts with the SO2 thus reducing the level of preservative and the wine in PET becomes more 'developed' than wine in glass. From the article this starts to occur for storage times longer than 8 months. But even at 12 months it had not resulted in a preference of the tasters for the wine in PET or glass.

Because the bottle of beer is pressurised with CO2 it would be much more difficult for oxygen to permeate through the PET bottle to make it go off. A possible problem with beer may be the loss of carbonation as CO2 permeates out of the bottle.

That said I bottle all my beer in PET but have never kept any long enough to check this out. But the there seems a consensus that it slowly goes off after an 8-9 month period.

 

[pdilley]

I can see a new slogan coming "Its got to be glass, or it will taste like a@@"

The important thing in the study is most wine drinkers can not differentiate up to the 12 month mark between PET and Glass. While a home brewer with a long aged cellar will not be going plastic, I can not but think the commercial wine industry will start to increase shipments in plastic and some creative marketing type will put a positive PR spin on the whole thing and most people in Oz will end up buying it.

Cheers,
Brewer Pete

 

[mwd]

Wonder if that was before or after the "Barrier Technology" type PET bottles.

I am sure I read somewhere but cannot find it now that Coopers PET bottles had some kind of nylon barrier between the double skin which is supposed to reduce the permeability of the plastic.

Most of my PET bottled brews are long gone within 3 months so cannot comment on long storage times.

Link to Barrier Technology "NEW" type PET.

 

[spazmodik]

Wonder if that was before or after the "Barrier Technology" type PET bottles.

I am sure I read somewhere but cannot find it now that Coopers PET bottles had some kind of nylon barrier between the double skin which is supposed to reduce the permeability of the plastic.

Make sure you use cold water to wash your PET bottles as the nylon is damaged when washing with hot water. I noticed that my original set of PET bottles (when I was stupidly using hot water against instructions), didnt hold pressure for very long. I have since ditched them, and the new sets I use seem to hold pressure much better. I only use them for the excess beer in the fermenter after filling a keg these days, but they sit on my shelf quite happily and age nicely. Havent left any for much more than 8 months though... Even the nylon has its limits.

 

[geoffi]

I will cheerfully go on using PET for beer. Mine are lucky to make it past two months after all, let alone 'full gestation'.