PET Bottles

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jhmtaylor

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I recently purchased 2 boxes of Coopers 750ml PET bottles and I am experiencing problems with some of them not sealing properly and the beer not carbonating. I have purchased additional caps and that was the problem in some instances and in others, the bottles are defective. Although they are cheap, it is annoying throwing away 15% of some brand-new items because of defects. Because they are only sold in boxes of 15 I now need to purchase another box of bottles for"just in case". Before I do so;
  1. Is this a common Coopers product problem? or
  2. The nature of the product?
  3. Is there an alternative brand with products of a more reliable quality?
 
If I were in your shoes, I'd be giving the Coopers support line a call or contacting them on their home brew forum. As with any product, they are covered by Australian consumer protection laws and must be fit for purpose. I have loads of Coopers PET bottles and almost never have a problem with sealing and carbonation. It does happen occasionally, but its not the same individual bottle failing. I would say less than 1% failure easy and I'm still using original lids although I have bought some replacements a long time ago. My oldest Coopers bottles are 10 years old but I recently bought a few "new" ones (90 x 2nd hand bottles only used once or twice) and they are fine.

You do need to tighten the lids down pretty firmly to get a definite seal and sometimes they're pretty darn hard to get back off. I've developed a callus on the web of my left hand from unscrewing lids. When I do find a soft bottle in a batch I just remove the lid and drop a single carbonation drop in then re-seal the lid. I have a bag of their sugar drops just for this purpose as trying to do it with granulated suger causes it to fizz up before you can get the lid down sometimes.

I'd have to say also that most of my flats occur in my non Coopers bottles. I have some MJs and others that I think were just HBS unbranded ones so my failure rate with Coopers bottles is nearly zero.
 
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If I were in your shoes, I'd be giving the Coopers support line a call or contacting them on their home brew forum. As with any product, they are covered by Australian consumer protection laws and must be fit for purpose. I have loads of Coopers PET bottles and almost never have a problem with sealing and carbonation. It does happen occasionally, but its not the same individual bottle failing. I would say less than 1% failure easy and I'm still using original lids although I have bought some replacements a long time ago. My oldest Coopers bottles are 10 years old but I recently bought a few "new" ones (90 x 2nd hand bottles only used once or twice) and they are fine.

You do need to tighten the lids down pretty firmly to get a definite seal and sometimes they're pretty darn hard to get back off. I've developed a callus on the web of my left hand from unscrewing lids. When I do find a soft bottle in a batch I just remove the lid and drop a single carbonation drop in then re-seal the lid. I have a bag of their sugar drops just for this purpose as trying to do it with granulated suger causes it to fizz up before you can get the lid down sometimes.

I'd have to say also that most of my flats occur in my non Coopers bottles. I have some MJs and others that I think were just HBS unbranded ones so my failure rate with Coopers bottles is nearly zero.
Thats consistent with my experience - had pretty much a zero failure rate over the years. I hadn't thought of the 'drop another sugar drop in' - will do that (if there is a) next time :)
 
Coopers pet bottles are normally really good. I do remove the tamper ring after the first use.
This gets ride of possible issues in sanitation; you only have to clean the cap and bottle.

I have seen other brand name caps with the tamper evident ring bottom out on the bottle hindering a completed seal.
 
Coopers pet bottles are normally really good. I do remove the tamper ring after the first use.
This gets ride of possible issues in sanitation; you only have to clean the cap and bottle.

I have seen other brand name caps with the tamper evident ring bottom out on the bottle hindering a completed seal.
After the first few times I used PET bottle lids with the tamper ring, I started removing them before first use. I have a new bag of black lids I obtained with a batch of gear that I need to do so I can use them.

One thing about home brewing is that a lot of people give up and there is plenty of "used" gear out there, if you can be bothered to look for it.
 
I only get the odd PET bottle that doesn't carbonate. As livo said, they last for years but need tightening fairly firmly.
 
I recently purchased 2 boxes of Coopers 750ml PET bottles and I am experiencing problems with some of them not sealing properly and the beer not carbonating.

When I used PETs, I never had any issues. The odd one maybe, but that could have been forgetting to sugar. Easily done.

That's another thing... If you're using the carb drops, IIRC 2 are needed for the 750ml. That might be a bit high, but I found one wasn't enough. Drops were average to poor at carbing and I went to measured doses of sugar instead. Always consistent results. I've long since stopped dosing bottles and siphon my finished beer into a second fermenter, dosed with a sugar water mix for the whole batch and fill the bottles from that.
 
If I were in your shoes, I'd be giving the Coopers support line a call or contacting them on their home brew forum. As with any product, they are covered by Australian consumer protection laws and must be fit for purpose. I have loads of Coopers PET bottles and almost never have a problem with sealing and carbonation. It does happen occasionally, but its not the same individual bottle failing. I would say less than 1% failure easy and I'm still using original lids although I have bought some replacements a long time ago. My oldest Coopers bottles are 10 years old but I recently bought a few "new" ones (90 x 2nd hand bottles only used once or twice) and they are fine.

You do need to tighten the lids down pretty firmly to get a definite seal and sometimes they're pretty darn hard to get back off. I've developed a callus on the web of my left hand from unscrewing lids. When I do find a soft bottle in a batch I just remove the lid and drop a single carbonation drop in then re-seal the lid. I have a bag of their sugar drops just for this purpose as trying to do it with granulated suger causes it to fizz up before you can get the lid down sometimes.

I'd have to say also that most of my flats occur in my non Coopers bottles. I have some MJs and others that I think were just HBS unbranded ones so my failure rate with Coopers bottles is nearly zero.
Thanks @livo. I took your advice and they are sending me some more bottles. No hassle! They also want the defective bottle back to investigate the cause. I am pleasantly surprised by Cooper's commitment to customer service. As a result, I purchased a second fermenter kit today because for numerous reasons; Ie needed more bottles, wanted a Cooper plastic hydrometer, and mainly because I want to be able to experiment with taste/flavors using small batches
 
Great. They are a globally recognised and trusted company. I'm not at all surprised with this outcome. Well done for making the effort.
 
I have a couple of hundred coopers bottles used repeatedly and don’t think I have had a problem that I could blame on the bottles. I take the tamper ring off the caps before first use.
 
I have a couple of hundred coopers bottles used repeatedly and don’t think I have had a problem that I could blame on the bottles. I take the tamper ring off the caps before first use.
My problem has been solved. "take the tamper ring off the caps". In some instances, the tamper-evident collar was causing the cap to "cross-thread" and preventing the cap from sealing. After removing the tamper-evident collar it works as it is supposed to.
 
I have just recently used one of the "only used once or twice" batches of Coopers PET bottles I purchased a few months back for the first time. I made a double batch of Brown Ale, which is yummy, but the point is that I bottled half in the fairly new PETs and half in Grolsch glass swing tops. The carbonation, although done identically on the same day, is chalk and cheese. The PETs aren't flat, but the glass swing tops are so much better. I've undone the lids on the second 15 PETs and dropped in an extra sugar lolly. It's why I have them, but I rarely ever need to use them. I drank the first 15 while comparing them to the glass ones just to be absolutely sure there was a problem. Hck.

I don't know if it's just the difference between PET and glass or if there is something wrong with this batch of bottles. I don't normally have any issue with carbonation in my old Coopers PETs. I didn't buy these ones new so it's just bad luck if they are dodgy. The lids were on firmly so I'm not sure what went wrong. Still a nice beer to drink but just less fizzy and no head. The bottles firmed up quite well, but I did notice that they went a bit squishy when chilled and they don't phsshh much when cracked. Hopefully the second half with extra lolly will be a bit better after I leave them for a week or so. The glass ones let out a really satisfying pop when you flip the lid and pour to a really nice glass of beer.
 
but the point is that I bottled half in the fairly new PETs and half in Grolsch glass swing tops. The carbonation, although done identically on the same day, is chalk and cheese. The PETs aren't flat, but the glass swing tops are so much better.

I found same. The PETS are fine, but results did vary. The carb drops were useless IME. I switched to sugar dosing and that made a noticeable difference to carb levels and consistency. I only use swing tops now and a flattie is very rare. Now I rack off my finished brew into a 2nd fermenter with a batch dose of sugar solution, as single dosing per bottle was a pain.
 
I've been bulk priming in a secondary fv for a long time. I'll know in a few days if adding a carb drop sugar lolly to the PETs has helped.
 

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