Canning to avoid bottle bombs

[Selloum]

Hi,

I would like to carbonate up to 5 volumes of CO2 but the bottles available in my country can only support up to 3 volumes of CO2. The thing is I cannot see how that is a proper measure of a bottle's resistance if they don't mention the temperature of those 3 volumes. For example: By looking at a chart (Zahm & Nagel) @ 38ºF/3.33ºC, 3 volumes is 15 psi of pressure, while @ 72ºF/22.22ºC it is 40 psi of pressure. Let's say a bottle is resistant up to 45 psi, technically I could carbonate up to 5 volumes @ 38ºF/3.33ºC and not fear bottle bombs because the pressure would be 34 psi, a safe number significantly below the max of 45 psi; assuming I keep the bottle refrigerated at that temperature and there are no defects.

Instead, I've been thinking of canning since I've heard that cans can resist pressures of up to 90 psi, sometimes up to 100 psi. Meaning that if I carbonate at 5 volumes of CO2 @ 38ºF/3.33ºC, I would need 34 psi of pressure, and if I leave the can outside @ 72ºF/22.22ºC, the pressure would be 76 psi. In this case, below the max pressure and no fear of any problems.

What is the psi that those 3 volumes are referring to exactly? Correct me if I'm wrong but a bottle's resistance should be measured with pressure and not volumes of CO2.

 

[Selloum]

I forgot to ask, as anyone ever carbonated up to 5 volumes in a can using an open filling system by purging the can with CO2 first then filling it up with the liquid? Would you need to over-carbonate above 5 volumes to avoid loss of carbonation? What's the foam situation like?

 

[Qhrumphf]

What on earth are you trying to can at 5 volumes? Attempting to package anything that's carbed at that level is gonna be a foamy mess no matter how you slice it.

If you insist on something that carbed, I'd bottle condition it.

But again, why?

 

[Selloum]

What on earth are you trying to can at 5 volumes?

Mixers and sodas.

But again, why?

Because 5 volumes is a max number for Mixers (tonic waters, ginger beers, etc). My range would be between 4 to 5 volumes.

If you insist on something that carbed, I'd bottle condition it.

Force carbonation is my go-to method for these types of drinks. Bottled-conditioned mixers and soda will lose their sweetness over time and the carbonation feels softer than force-carbonating them.

The issue is not what I'm trying to carbonate but rather figuring out the bottle specs to avoid bottle bombs, and if people have had experience with canning highly- and force-carbonated products.

 

[Qhrumphf]

Ahh, okay, that makes more sense. I assumed this was for beer.

 

[Qhrumphf]

Since soda doesn't form a head like beer, I presume you'd have less of a foaming problem.

And I presume that normal temp ranges (ie up to room temp) are the unspoken factor in how many "volumes" a container can hold. I imagine a vessel rated to "3 volumes" would still burst at 2.7 volumes if you heated up to 150F. Like you said, PSI is a more useful metric.

 

[Vale71]

Beer bottles depending on the applicable standard can hold up to 10 bar before actually bursting. The "3 vols max" is a recommendation based on maximum expected temperature in the worst possible conditions like say, a truck sitting in traffic at noon in Florida or in the brewery when undergoing pasteurization in the bottle.

For example this techical standard for German breweries (on page 8) gives a rating of 10 bar for beers carbed up to 6 g/l of CO2 or 3.06 vols which corresponds to a temperature of 92°C. While you won't reach such high temperatures when pasteurizing beer there is always a safety margin factored in to account for variability in production.

https://www.vlb-berlin.org/sites/default/files/2020-04/STLB Bierflaschen aus Glas_August 2017_0.pdf

 

[Selloum]

According to this technical std. for German breweries, the pressure rating of a bottle is connected to the volumes to account for variability in production? Using the same bottle with beer @ 4 volumes the rating would be reduced to a pressure below 10 bars for safety reasons, correct? Are they using these numbers to avoid liability claims? That is quite the huge safety net if you need 92ºC @ 3 vols of CO2 to burst a bottle.

"Set points for EW bottles with a CO 2 content above 6 g / L are to be agreed individually"
What do they mean by "agreed individually"?

 

[Qhrumphf]

That's a hefty safety margin indeed. Explains why you can have ceiling soaker gushers without bottle bombs.

 

[Vale71]

What do they mean by "agreed individually"?

It means if you're a brewery and you're buying a few million bottles you can have them manufactured to whatever specs you desire...

 

[Birrofilo]

Sparkling wine bottles are of the toughest kind. Some of them can be closed with crown caps, 29 mm diameter. For what I know, it is normal to bottle sparkling wine at 6 volumes of CO2. Just by taking one in your hands you will understand how tough they are. I would say they are more robust than cans, and you can referment in the bottle if you want to make sparkling wine.

 

[Selloum]

I know champagne and sparkling wine bottles are stronger but I can't justify buying them due to their size and cost to fill them with a mixer. I also like the idea of cans because they will buckle before bursting.

According @Vale71 it makes more sense to have a safety net due to product variability and and to avoid litigations from consumers but from an engineering point of view you could have more volumes of CO2 without going over the pressure limits of the bottle and not fear bottle bombs.

 

[Birrofilo]

Never bought a bottle in my life
Distribution of empty bottles is hugely inefficient, distribution of full bottles is much more efficient, you buy the wine and get the bottle "for free". Certainly that requires planning and now you might not have the time to begin the purchase of sparkling wine for consumption.

If you distill, or have a friend who distills, you could consider buying bottles enough for an entire batch, let's say 40 bottles, with sparkling wine inside that is, you distill the wine and you obtain the brandy (or the acquavite di vino), and the bottles are yours for immediate use, and they are reusable. If you consider the distillate "value", the bottles are free.

If you can find glass Coca-Cola bottles for crown cap, they are also very robust*, more than the usual beer bottle for what I know. Maybe you could find some restaurant, pub etc. having bottles to give away for free. Here in Italy restaurants never serve Coca-Cola in plastic bottles, they will serve you the glass bottles, so restaurants might be a good place where to find a cheap provision.

* Some people measured the pressure that plastic Coca-Cola bottle can withstand, which is reportedly 17,8 bar (!). Glass bottles I presume are of comparable strenght.