Large PET bottle source?

The Homebrew Forum

Help Support The Homebrew Forum:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.
Years ago as a young engineer I remember being summoned to the head office of our local pop manufacturer by the Engineering Manager who was a mate of mine from Leeds. He pulled out the first 'plastic' pop bottle I had ever seen! In answer to my question “What is that” he said “That young scomet is the future!” He then went on to explain in detail how it superseded glass in every metric that was critical to his product. Shame they hadn't considered the damage it was going to do to the planet.
Fast forward to the present - I have been using large plastic pop bottles for my extra beers since I started kegging about seven years ago. In this time I have given hundreds away, all with my email address on with a request for comments. I have not had a single complaint to date. About 5 years ago I kegged an RIP at 13.8% I didn't care too much for the taste of, so I threw it into 'pop' bottles and left it in a cool dark place. This last xmas I opened a bottle out of curiosity it was imo superb, my only regret was having given so many away!!
I have heard all these criticisms of pop bottles over and over but what gets me is; How does evil oxygen cross the PET with a deltaP of ~1.5bar!? That makes no sense, just keep them dark with the lids on tight...

Come on guys we are not bottling Grange Hermitage here! it's a few beers to go etc..

CHEERS - scomet
 
Last edited by a moderator:
Years ago as a young engineer I remember being summoned to the head office of our local pop manufacturer by the Engineering Manager who was a mate of mine from Leeds. He pulled out the first 'plastic' pop bottle I had ever seen! In answer to my question “What is that” he said “That young scomet is the future!” He then went on to explain in detail how it superseded glass in every metric that was critical to his product. Shame they hadn't considered the damage it was going to do to the planet.
Fast forward to the present - I have been using large plastic pop bottles for my extra beers since I started kegging about seven years ago. In this time I have given hundreds away, all with my email address on with a request for comments. I have not had a single complaint to date. About 5 years ago I kegged an RIP at 13.8% I didn't care too much for the taste of, so I threw it into 'pop' bottles and left it in a cool dark place. This last xmas I opened a bottle out of curiosity it was imo superb, my only regret was having given so many away!!
I have heard all these criticisms of pop bottles over and over but what gets me is; How does evil oxygen cross the PET with a deltaP of ~1.5bar!? That makes no sense, just keep them dark with the lids on tight...

Come on guys we are not bottling Grange Hermitage here! it's a few beers to go etc..

Sorry I didn't bullet point all this and use aligned paragraphed indents etc but I stopped being impressed by that a long time ago……

CHEERS - scomet
I never said that the sky was going to fall in! Just trying to be helpful.
 
Last edited by a moderator:
Come on guys we are not bottling Grange Hermitage here! it's a few beers to go etc..

The discussion was about long term storage and at the end of the day its personal choice if you think there is no problem putting alcohol into a bottle not designed for that purpose fine carry on, there is no harm in discussing possible downsides of doing so in the forum and as i said having read a few threads about it i decided to move to glass as wines have a much higher %ABV i also like the feel of glass compared to floppy plastic bottles.
 
Last edited:
Yes Chippy I bottle wine in glass and about half of my beer - the reason I use PET is when we are away in the m/home it saves on space and weight. The wife and I can empty a 2ltr bottle after a bike ride or walk, its just about the right size. What we need on here is a scientist to explain this transfer of gasses, (but then if its too technical I would not understand it anyway I suppose). Most of my plastic bottles are ex cider bottles (5% ABV) and years ago I used to buy 2ltr, or maybe 4 pt bottles of bitter brewed by the Aston brewery (now defunct I believe) so there is an history of PET being used commercially.
I totally agree with the comment about the damage to the planet - that's why I will never buy bottled water, its probably just filtered tap water anyway.
 
What we need on here is a scientist to explain this transfer of gasses, (but then if its too technical I would not understand it anyway

When this was discussed at length years ago I emailed a few places like the food standard agency etc most got back to me but sat on the fence and wouldn't give me a definite answer either way, that is when I decided to move to glass.

As I said above its down to personal choice if members don't think there is an issue they will carry on using plastic if they read this and decide to move to glass bottle manufacturers gain a few sales and the recycling crew will have a little less to pick up that week.
 
Last edited:
And here's me thinking it was all about 'Large PET bottle source'....

While the OP was originally discussing the size of pet bottles the conversation had moved on to safety of long term storage at the point you posted post 41.
 
I'm sure someone posted in this post about sourcing 3L pop bottles but not checked. I have just seen an advert for Farm Foods for 3L bottles of Coke and other drinks.
 
I'm sure someone posted in this post about sourcing 3L pop bottles but not checked. I have just seen an advert for Farm Foods for 3L bottles of Coke and other drinks.
Will have a look next time I head past. Will just man I need to drink it all in one sitting :)
 
The only thing i can say is, you never see ale for sale in pet bottles in supermarkets and shops it is always sold in glass or cans, which tells me pet has a shelf life and must be permeable, i could be wrong
 
The only thing i can say is, you never see ale for sale in pet bottles in supermarkets and shops it is always sold in glass or cans, which tells me pet has a shelf life and must be permeable, i could be wrong

You are not wrong . . . . . PET bottles are permeable to oxygen. Those bottles that are used to package oxygen sensitive products are treated (usually a barrier coating) to reduce oxygen ingress. However, it is a gradual process, so many homebrewers do get away with using PET bottles.

But there are other reasons why commercial brewers do not use PET bottles. For example: the cost of suitably coated bottles compared with glass and/or aluminium cans; and also pressurised PET bottles will not withstand pasteurisation temperatures.
 
I will say it again - Drinking year old beer in PET bottles not a problem for me. I do not buy PET bottles, I reuse other peoples. I have used spring water bottles presumably not treated to eliminate oxygen ingress. I have mentioned before bottles store at a higher pressure inside than out, I do not believe oxygen transfer to be a real problem
 
It's a long time (OK, a very long time) since I studied the physics but I understand that a positive CO2 pressure doesn't stop oxygen getting in. Something about partial pressures. However, if the beer is tasty enough it probably won't be around long enough to be a problem...
The PET bottles sound ideal for kombucha which can build up high pressures on a second ferment but doesn't mind oxygen.
 
It's a long time (OK, a very long time) since I studied the physics but I understand that a positive CO2 pressure doesn't stop oxygen getting in. Something about partial pressures. However, if the beer is tasty enough it probably won't be around long enough to be a problem...
The PET bottles sound ideal for kombucha which can build up high pressures on a second ferment but doesn't mind oxygen.

Thank you . . . . . I was beginning to feel that I was a lone voice.
I also had an inkling that the two way passage of gases through thin plastic films/bottle walls was something to do with partial pressures (Dalton's Law). I have done a bit of searching on the internet and found a lot of information on this topic. Much of it is in highly technical scientific papers, which are really heavy going. I also found several references to Fick's law of diffusion and Henry's gas laws. They appear to be the primary mechanism for the permeation of gases through plastic membranes, which is a function of the properties of both the polymer and the particular gas in question. So, oxygen will slowly diffuse into the bottle at the same time as carbon dioxide is slowly diffusing out of the bottle because they are different molecules.

However, in the big scheme of things it probably doesn't matter to the majority of homebrewers who choose to use old pop bottles to package their beer, as long as it tastes good . . . . . which I am reliably informed is the case. So, I will say no more 😐

PS - If anyone is interested, the two articles attached give more information:
 

Attachments

  • Eastman - Gas Permeability of PET.pdf
    2.8 MB
  • The permeability of polymers.pdf
    415.5 KB
The only thing i can say is, you never see ale for sale in pet bottles in supermarkets and shops it is always sold in glass or cans, which tells me pet has a shelf life and must be permeable, i could be wrong

On the other hand, you do see cider being sold in plastic bottles, so I don't think you can jump to the conclusion based on that.


Anyway, I bought a dozen of the swing-top PET bottles, arrived today. Jeez, they weigh nothing, don't they? Aesthetically I do much prefer glass, but it's not bad thing to have a few PET bottles in stock, I think.
 
Just to update, I've ended up trialing some 3l 7up bottles. Green PET, so not brown like I'd hoped for, but better than clear. Am still keeping them in a box with the lid on to keep away from UV.
 

Latest posts

Back
Top