Bottle Pressure Limits

[Chalkyt]

I have managed to get some information from a few manufacturers about the pressure limits of their bottles.

This information seems worth sharing as heat pasteurising and the risk of bottle bombs seems to be a frequent topic. So here is what I have found... use the information to help make your own decisions about how far to go down the bottle bomb path.

Visy Glass (one of Australia's large.. glass bottle manufacturers) says...

With our bottles, we typically talk in GV (Gas Volume). Gas Volume is a unit less measure, of how much C02 is present vs liquid.
Ciders are typically less than 3GV (Gas Volume) and sometimes up to 4GV, which results up to 12Bar or 1.2MPa. Our industry beer bottles are typically rated to 4GV; Product Results

We do not recommend reusing one-way bottles for home brewing, and when using new bottles or even returnable bottles in good condition, they should not be filled beyond the rated capacity.

ShangHai Misa Glass Co. Ltd. Beer Glass Quality Standards refer to GB4544 (a China Standard). I have mentioned this in other posts but following is an extract from the Misa web site...

1, internal pressure.
The internal pressure resistance item is one of the most important safety indicators for beer glass bottles. Due to the filling of beer with a certain amount of CO2.therefore,Beer bottle as a beverage bottle filled with CO2 should strictly meet the internal pressure requirements specified in GB4544.The current standards in China stipulate that the qualified product index is ≥1.2 MPa(all developed countries are ≥1.6 MPa,Japan International Standard is 1.8MPa), otherwise,Due to the lack of internal pressure resistance of beer glass bottles,Will cause beer glass bottles to fill,transport,In the process of consumption, there was a bottle burst accident.

The inspection data shows that the qualified rate of the internal pressure resistance of recycled beer glass bottles was 25% lower than that of new beer glass bottles and selective beer glass bottles.

I found some manufacturers who have published the pressure ratings for a limited number (but not all) of their bottles so I looked for any relationship between the weight and capacity of bottles vs pressure rating. This information is attached and as expected, does show a rough relationship but the individual bottle rating is probably more important.

I guess the most relevant information from all of this is that new 330 ml or 12 oz bottles (commonly used by many of us) seem to be rated by manufacturers at 4 volumes of CO2 which is only 0.36 MPa (52psi) at room temperature of 20C/68F. However if a bottle carbonated to 4 volumes of CO2 is heat pasteurised to something like 65C/149F, the pressure will reach 1.26 MPa (183psi) which is at the limit of the bottle rating and getting into "Bottle Bomb Land".

So, if recycled bottles are being used and downgraded by 25% as recommended by Misa Glass, it seems that carbonating to 2.5 volumes is about as far as it is prudent to go for heat pasteurising. The recycled bottle downgraded rating would now be 0.9MPa (135psi) and the pressure at 65C/149F will approach 0.75MPa (109psi). This seems to be a reasonable margin of safety.

Similarly, bottling for a still sweet cider at around SG1. 015 would generate the same sort of pressure (0.75MPa or 109psi) if left to fully ferment, and certainly approach volcano or "Bottle Bomb Land" if the bottles were left in a warm room of say, 30C/86F.

Hmm, food for thought.

 

[Rick Stephens]

I had my one and only bottle bomb last week while pasteurizing a skeeter pee batch. I've done well over 50 gallons of bottle carbed and pasteurized ciders and pee this last 6 months.

The 10 gal. skeeter pee batch with the bottle bomb was interesting in that I decided to catch it and bottle on the way down while still in active primary fermentation. Last skeeter pee batch took weeks to bottle carb after letting it finish dry and adding sugar for taste and priming bottle carb. So I decided to guarantee active fermentation. After 3 days opening a test bottle emptied half the contents in a geyser. Totally different from skeeter pee that is bottled after primary is done, which took many weeks to finally reach the level I wanted. With this last batch I blew one bottle in the high temp bath 20 seconds after dropping it in. Using relatively young Belgian pints, which are fairly high rated for pressure.

The end product of this batch after refrigeration opens with the pop and hiss of just a couple volumes of C02. Pretty much perfect. I don't go much higher levels the slow way and never had a geyser. So I think the variable added by having all that suspended yeast and active fermentation was in the end a negative, even though it worked out other than the one bomb.

Only point of the post is that there are a lot of variables when bottle carbing and pasteurizing. Modifying them should be done carefully and limit the number of variables you make changes to on any one batch.

Rick

 

[AzOr]

Thank you so much Chalky. This info is very helpful. I use both 12 and 22 oz brown bottles and have had the following issues;
-the cap pops off on at least one bottle out of 20.
-I've had less than a half dozen bottles break while pasteurizing. All of them have been the 22 oz brown beer bottles. Ive never had a 12 oz break. This is over the course of six or so seasons and at least 20+ batches.

I usually carbonate to about 2.5 to 2.7 volumes. Of course this is based off my keg pressure calculations, so definitely not scientific.

I occasionally come across heavier duty 500ml bottles and those seem to be made for higher pressure but since I don't exactly know the specific type and brand of bottle, it's just a guess. I hang on to those and hopefully will start collecting more.

When pasteurizing, please wear safety goggles and some sort of gloves. I wear those elbow length padded rubber gloves for bbqing.

 

[Chalkyt]

Thanks for the feedback.

Rick, I had a similar experience bottling for a sweet cider "on the way down" at 1.015, then pasteurising when the pressure gauge reached 2.5 volumes. In theory that should have been O.K., and was until I clunked two bottles together after removing them from the bath, then "boom".

So, they must have been close to the pressure limit and the shock was enough to set them off (note to self... be more careful next time). I guess that your observation about other variables having an unknown influence makes sense. In any case, the cider bottled at 1.015 with a planned finish of 1.011 ended up a bit too sweet so next time I will try finishing with bottling at 1.012 to finish at 1.008, etc, etc until I find the "magic spot".

The plan was to have a sweet "lighter (alcohol, say 6%) sparkling cider. I figured that fully fermenting from 1.050 then topping up with sugar to 1.015 and fermenting to 1.011 for carbonation (i.e. 2 vols) would get close to 8% ABV which is a bit more than SWMBO wants.

In any case this was a bit of "mad science experiment" with two small batches (although it was a shame to lose two bottles!). I was doing the batches to compare SO4 and MO2 (which I hadn't used before). The "bomb" was from the SO4 batch which I found to ferment more robustly than the MO2. I "bailed out" with pasteurising the MO2 batch since the pressure gauge had leaked a bit so I didn't really know what the pressure was in the bottles. I put the bottles in the fridge in order for some of the CO2 to be absorbed into solution, released then resealed the caps, and heat pasteurised. The carbonation in this batch seems to be around 2 volumes now, so I suspect that originally it might have been approaching 3 vols which could have been a bit of a problem.

Azor, I hope the data helps people. Decent information about bottle strength is a bit hard to find. I was really surprised when Visy came back with their information and later found that with some (but not all) makers if you dig far enough into their specs, you can find pressure ratings. A common pattern is that they make beer bottles to withstand 4 vols at 20C (i.e. when they are bottled), which can translate into something close to their limit of 1.2MPa when heat process pasteurised. The 25% reduction in rating for recycled bottles is worth noting. I did find a reference to this with the U.S. Department of Commerce, but as with such things they are sometimes buried in an obscure reference and unfortunately I haven't been able to find it again.

There is an old study from the 1950's (Google... Jo Morgan Teague, Ohiolink). It is a dissertation for a PhD and some of the data shows that the range of bottle strengths in a batch can be up to 50% above and below the mean batch rating. Although glass bottle technology may have changed since that time, it does suggest that low spec bottles could be out there.

Cheers!

 

[DuncB]

Thanks for this info, maybe better for me to use champagne bottles if I'm going to pasteurise any beer or what about a PET bottle?

 

[Chalkyt]

You will see from the attachment above that in the samples I was able to get, Sparkling/Champagne bottles are rated at 5.0-7.0 by their manufacturers. Claude Jolicoeur suggests that they are good for 3.5 - 5.5 Volumes of CO2.

I haven't used PET bottles but I understand that over time they allow two way transfer of gas. i.e. O2 gets in and CO2 gets out. Others with more experience with this might be able to help.

 

[DuncB]

@Chalkyt I think you are right about the PET bottles not a long term solution.
Maybe looking at the pressure raise issue from the wrong end. I understand that corney kegs have a very high pressure rating. So perhaps bulk pasteurise in there and then counter pressure fill. Could even do the pasteurise at a lower pressure and then force carb up and then bottle?

 

[Maylar]

Thanks for this info, maybe better for me to use champagne bottles if I'm going to pasteurise any beer or what about a PET bottle?

PET bottles will not survive. The bottom will bulge at about 45 psi.

 

[AzOr]

Thanks for the feedback.

Rick, I had a similar experience bottling for a sweet cider "on the way down" at 1.015, then pasteurising when the pressure gauge reached 2.5 volumes. In theory that should have been O.K., and was until I clunked two bottles together after removing them from the bath, then "boom".

So, they must have been close to the pressure limit and the shock was enough to set them off (note to self... be more careful next time). I guess that your observation about other variables having an unknown influence makes sense. In any case, the cider bottled at 1.015 with a planned finish of 1.011 ended up a bit too sweet so next time I will try finishing with bottling at 1.012 to finish at 1.008, etc, etc until I find the "magic spot".

The plan was to have a sweet "lighter (alcohol, say 6%) sparkling cider. I figured that fully fermenting from 1.050 then topping up with sugar to 1.015 and fermenting to 1.011 for carbonation (i.e. 2 vols) would get close to 8% ABV which is a bit more than SWMBO wants.

In any case this was a bit of "mad science experiment" with two small batches (although it was a shame to lose two bottles!). I was doing the batches to compare SO4 and MO2 (which I hadn't used before). The "bomb" was from the SO4 batch which I found to ferment more robustly than the MO2. I "bailed out" with pasteurising the MO2 batch since the pressure gauge had leaked a bit so I didn't really know what the pressure was in the bottles. I put the bottles in the fridge in order for some of the CO2 to be absorbed into solution, released then resealed the caps, and heat pasteurised. The carbonation in this batch seems to be around 2 volumes now, so I suspect that originally it might have been approaching 3 vols which could have been a bit of a problem.

Azor, I hope the data helps people. Decent information about bottle strength is a bit hard to find. I was really surprised when Visy came back with their information and later found that with some (but not all) makers if you dig far enough into their specs, you can find pressure ratings. A common pattern is that they make beer bottles to withstand 4 vols at 20C (i.e. when they are bottled), which can translate into something close to their limit of 1.2MPa when heat process pasteurised. The 25% reduction in rating for recycled bottles is worth noting. I did find a reference to this with the U.S. Department of Commerce, but as with such things they are sometimes buried in an obscure reference and unfortunately I haven't been able to find it again.

There is an old study from the 1950's (Google... Jo Morgan Teague, Ohiolink). It is a dissertation for a PhD and some of the data shows that the range of bottle strengths in a batch can be up to 50% above and below the mean batch rating. Although glass bottle technology may have changed since that time, it does suggest that low spec bottles could be out there.

Cheers!

Chalkyt I never considered that a recycled bottle would have a reduced capacity. I think I will start to transition to the heavier duty 500ml bottles.
Thanks again for the info

 

[Chalkyt]

Yes, that was somewhat of a surprise to me. It can be heavy going, but the Jo Morgan Teague study mentioned above has some data on this. Although it is quite an old study and can be heavy going at times, I imagine that the findings hold true today. Basically as part of the dissertation, the author compared breaking pressure of bottles with "pristine surface" (i.e. fresh from production) and "abused surface".

My interpretation of the study is that the "abused surface" involved creating surface imperfections by clanking the bottles together and running them through a metal conveyor, etc, etc. The result being much like the state of recycled bottles. Although different design bottles had different results, overall the abused bottles in some cases were up to 50% weaker than their pristine counterparts. This suggests that surface imperfections have quite an effect on bottle strength, hence the suggested 25% downgrading for recycled bottles.

Without sending everyone dizzy with numbers a couple of sets of breaking pressure figures for different bottle designs and weights were "Pristine"396psi - "Abused" 275psi, "Pristine" 531psi - "Abused 276 psi. Make of it what you will.

 

[DuncB]

There must be a pretty good tolerance on the bottles in their range of use though. Certainly here in NZ buying crates of beer in 750ml bottles and returning them is very common. I've got quite a lot of them as bigger bottles is fewer washings and caps etc. although I'm only bottling for giveaways now really.
All of these bottles have signs of wear and tear from the bottling processing plant. There is no way they can say a bottle has been used too many times via data, they aren't bar coded. Maybe they remove any chipped ones and then process the rest and if they fail during bottling they go in the broken glass pile.

 

[Chalkyt]

I am not a lawyer, but I suspect that the "advice" that common beer bottles are not suitable to be re-used is intended to protect the manufacturer. Certainly, bottles for recycling are not uncommon in some markets.

Among "my scratching around" I came across an article from the Ohio Law Journal by a Carl Spangenberg. The article looks fairly comprehensibly at both the technical and legal aspects of causes and who is responsible if a bottle explodes, and takes the view that...

"A bottle, even one that has been fairly abused, ought to stand about 150 pounds per square inch in pressure; but even under agitation and with heat, it is seldom that you can get a bottle of beer up above 50 or 60 pounds per square inch internal pressure."

I just throw this in for general information, as the debate has been going on for a long time. After all the article was published in 1963!

 

[doublejef]

Hello there,

Did anybody have issue with bottle caps when pasteurizing?

I am using 75cl Champegnoise bottle that can support high pressure so there is no risk of bottle explosion, I was assuming that if a bottle was really over-carbonated, the cap will blow but instead of that, it leaks slowly and release CO2. The cider is finally nearly still, I can hear a little pchittt when opening the bottle so the cap is not fully unsealed, but it is way to still for a semi-dry cider. Not all the bottle in the batch has this problem but afterward, I can’t see which bottle is ok and which is not, so I can’t separate it.

Do you think it’s a problem of a cap quality or it’s just something unavoidable?

 

[DuncB]

How did you get the pressure in the bottle in the first place?

 

[doublejef]

Plastic bottle test + opening one bottle every days + opening two bottle just before pasteurize all the other. I drank it don't worry.
The bottle fermentation was very slow (more than 2 weeks) because of the temperature and very poor in nutriment cider. So The monitoring was quite precise. I'm quite sure it was not overcabonated.
Also I assume that if it was a pressure problem, the cap can be like a valve (as it not pops off completely and finally stay airtight) and keep enough CO2 inside the bottle once pressure went down.
Did anybody use to pasteurize in champegnoise bottle with 29mm cap ?

 

[DuncB]

Are you sure they weren't undercarbonated? If really flat and sweeter than at time of packaging maybe they were'nt carbed fully before pasteurising stopped it. Plastic bottles probably warm up a bit quicker , if all bottles together some will be cooler than others.

 

[doublejef]

Sorry I forget to mention that I saw bubble coming from the caps when under water and heard somme bottle leaking.

 

[DuncB]

ahh, so they did leak some of them, I've only got an Emily Capper for my Champagne caps but have never tried pasteurising them. But seems like a capping failure. If not off maybe you could prime and go again?

 

[doublejef]

Pasteurization is done so I could add yeast and let it ferment again a couple of day and pasteurize again but I have more than 200 bottle so it's quit a big job. Moreover, I can't see wich bottle need to be re-carbonated.
My main goal now is to now if it will always be the same issue or if I just have to use better quality cap because I plan to do 200 bottle more...

 

[DuncB]

How about filling some bottles with soda water or lemonade cheapest you can find and do a repasteurising test to see if it's your technique or the caps.
You'd need to get some different caps as well. What capper do you have bench or the emily lever type?
Whenever I cap anything I try and do the first cap on and then " recap " it with the bottle twisted 90 degrees. Not sure if this helps just makes me think it's more secure.

 

[AzOr]

Hello there,

Did anybody have issue with bottle caps when pasteurizing?

I am using 75cl Champegnoise bottle that can support high pressure so there is no risk of bottle explosion, I was assuming that if a bottle was really over-carbonated, the cap will blow but instead of that, it leaks slowly and release CO2. The cider is finally nearly still, I can hear a little pchittt when opening the bottle so the cap is not fully unsealed, but it is way to still for a semi-dry cider. Not all the bottle in the batch has this problem but afterward, I can’t see which bottle is ok and which is not, so I can’t separate it.

Do you think it’s a problem of a cap quality or it’s just something unavoidable?

I have not had that issue. I have had caps pop when in the water bath. Scares the beejeezus outta me. I've never lost carbonation through a slow leak though. I'm using standard beer bottles (12 and 22 oz) and some Belgian bottles.

 

[Chalkyt]

In some earlier heat pasteurisation/bottle bomb trials using soda water in bottles (didn't want to waste good cider) I got the the water bath temperature up to near boiling point. Then "boom" which I thought was a bottle bomb but turned out to be a cap blowing off a used Peroni bottle. The other bottles were O.K., including a commercially bottled beer.

I assume that it was just poor capping on my part and since then I have made extra sure that I apply lots of pressure to the capping lever (I use a "Superautomatica" type manual capper). I must say that I now fully submerge bottles being pasteurised in a hot water bath and have only found the odd one or two leaking/bubbling caps at high pressure which seem to reseal once the bottles cool down. I guess it might be that the plastic seals inside the caps soften and leak at the pressures generated while pasteurising.

I also found that the Grolsch type bottle seals started leaking and bubbling at around 75psi. Grolsch have acknowledged that this is the case (see a post by Beaudoin 9 April 2013) . I am not sure if it is deliberate but in any case it seems to be useful protection against bottle bombs when using this type of bottle.

 

[doublejef]

How about filling some bottles with soda water or lemonade cheapest you can find and do a repasteurising test to see if it's your technique or the caps.
You'd need to get some different caps as well. What capper do you have bench or the emily lever type?
Whenever I cap anything I try and do the first cap on and then " recap " it with the bottle twisted 90 degrees. Not sure if this helps just makes me think it's more secure.

I use this one

I think it's a good quality one.

Reading all your message, I'm thinking that the problem come from the caps.
I'll will try another type next time..

Thanks for your answer everybody.

 

[DuncB]

THat is a good capper would be difficult to say others were better.

 

[GratefulBear]

All you guys with bottle bomb issues, did you use campden tablets too or just pasteurize?

 

[Maylar]

It wouldn't matter.

 

[GratefulBear]

It wouldn't matter.

I agree that it wouldn't matter during pasteurization, but some of the above posters had bottle bombs after pasteurization. Don't campden tablets help stop the little guys from doing their thing after bottling?

 

[Maylar]

I agree that it wouldn't matter during pasteurization, but some of the above posters had bottle bombs after pasteurization. Don't campden tablets help stop the little guys from doing their thing after bottling?

Nope. At that level it's just an anti-oxidant.

 

[GratefulBear]

Nope. At that level it's just an anti-oxidant.

What do you mean by "that level"? Is there a typical amount that is used at bottling that only functions as an anti-oxidant? Can you use more to stop refermentation? Or are you referring to the timing of the campden tablets, specifically? Thanks, still learning about preventing bottle bombs. I've been kegging since I started brewing so not normally an issue for me. I also thought campden tablets and sulfites were the same thing, but now I'm thinking they're two different chemicals

 

[Raptor99]

Campden tablets are potassium metabisulfite, so yes they add sulfites. But they can't stop active fermentation.

After pasturization the yeast should all be dead, so fermentation cannot restart. If you add campden tablets (akak Kmeta) before pasturization it can help to prevent oxidation.

 

[Chalkyt]

Going off at a slight tangent but just to add to my earlier post, I heat pasteurised a couple of batches yesterday and kept watch for any bubbles from under the caps. Sure enough, there was the odd bubble (about one per second) from one or two bottles.

Those batches were carbonated to 2.2 vols (2.2 bar or just over 30psi). I used a souse-vide heater to hold the bath at 65C so by the time the bottles had reached 64C (after about 10 minutes in the bath), enough pasteurisation had taken place. The bottle pressure reaches just under 90 psi at this temperature. Once the bottles had cooled to below 60C I put the suspect ones under water and the leaking had stopped so I do suspect that the cap seals soften a bit with heat. I wasn't smart enough to mark the bottles so I won't be able to tell if their carbonation is different to the others unless they have gone quite flat.

Maybe on another occasion it might be worth sacrificing a suspect bottle and letting it cool down in the bath. This will well and truly over-pasteurise it, but should give an idea of at what pressure/temperature the leaking starts/stops. As well as the "quality" of my capping, I imagine that a big variable will be the seal material in the caps which possibly is different for different cap manufacturers... Hmm, always something new to fuss about!

 

[doublejef]

Ok so I'm not the only one having this problem.
This week-end I pastorized a batch of bottle that I let fermented too long, I had a lot of cap poping also a few bottle bomb (even it was big though ones).
I was affrid of loosing also alcool when the cap is leakiig but it's evaporing at 80°C so I don't think there is a risk here.

 

[Maylar]

What do you mean by "that level"? Is there a typical amount that is used at bottling that only functions as an anti-oxidant?

Campden (sulfite) is used at different times for different purposes. At the start of a batch, before pitching yeast, we use it to kill bacteria and wild yeast. At racking and at bottling it's used to inhibit oxidation. As noted above, it can't stop an active fermentation.