Max. CO2

[Rambling1]

I was hoping you all could help me with a problem I'm having. I have a small soda company and have just begun pasteurizing cans. As you can guess we've had some cans pop on us! I believe the can max recommendations are 90 psig (6.2 bar). I guess my simplest question is what formula do I use to figure the max Vol of CO2 I can put in a product and pasteurize at 140 degrees and stay below 90 psig or 6.2 bar?

I'm filling at approximately 36 degrees if that is needed to figure into the equation. Really would appreciate any help!

[UnFermentable]

Unfortunately there is not an easy formula for this question. You need to know the head space volume, the product pH (and probably more technically Total Acidity) and conduct some molar math for a proper calculation. About 3.1 volumes (6.075 g/L) is going to be your tipping point (+/-) if you are looking to reach a peak temperature of 140*F (60*C). Beer, most likely having a higher pH, could likely go a few points higher.

The larger questions begs to be asked....Why do you want to pasteurize your soda? Most US made sodas do not undergo pasteurization, but rather make use of benzoate, sulphate or sorbate. Pasteurization requires a lot of process energy and labor time in comparison.

[NewarkBrewingCo]

We pasteurize here with our max co2 roughly 2.8/2.9 vol. Weve had issues with popping cans as well.
1. make sure your fill levels are on point.
2. Make sure your cans aren't heating up too quickly. We have a tunnel which takes about 50 mins for the cans to go through. Our first zone is roughly 20 celsius, our second 30, our third 50 and then our hot zone is 67.5 celsius. This generates roughly 25-50 PU's depending on where in the tunnel the can is. CHinese pasteurizer so it isn't even.

We have an Ecklund-Harrison PU meter and the product gets to roughly 63 degrees celsius during the pasteurizing process. I would suggest getting one of those so you are always on point but they are not cheap.

As far as the science, PV=nRT formula would probably do the trick. However you would need to know the volume of the headspace and then assume all CO2 goes into the headspace during pasteurization.