Before submitting this thread for deletion (claiming it's been asked a jillion times before and answered definitively), please read my question thoroughly. I tried my best to find a proper answer and will cite what I found, but in the end, these answers were "lacking"... I know that the ACS claims that the pressure of a shaken soda can is unchanged, but I have a few problems with this claim: Tests with larger bottles DO show palpable differences: I did a few simple double blind tests with 2-liter bottles of soda sitting for a day at room temperature and my blinded testers were able to identify the shaken soda more than 90% of the time, suggesting to me the effect is easier to detect in larger bottles than in small (rigid) cans. Equilibrium seems to be assumed: And (ignoring the theoretical impracticality of true equilibrium), a shaken can is NOT in equilibrium for at least a few minutes after shaking. So I claim the argument that pressure doesn't change is based on shaking the can as vigorously as you want, and then letting it sit there and returning to equilibrium (an hour or so later at least), after which, the pressure would have reduced to its "pre-shaken" state in agreement with Henry's Law. Of many posts, I found only one on this site that might confirm my claim: here a user "bystander" explains that the pressure WILL CHANGE (he didn't specify whether higher or lower) shortly after shaking due to both low pressure effects (he says "cavitation")... his use of the scientific jargon is really confusing as it seems he is purposely using fancy language to sound erudite. does he say pressure drops? it's possible he is claiming pressure actually drops (instead of my claim it rises). I can't tell too well, even after reading the entire thread. If cavitation creates pockets of low-pressure, this should lower the pressure in the can, and this seems not to happen, or I misinterpreted what he is saying (which is likely). so here is my suggestion: for the first 90 seconds after shaking a can, the pressure in the can definitely rises, but by a small amount (maybe 5-10 psi), but this is enough to be palpable in a larger soda bottle. This is the result of shaking, which, similar to higher pressure (and the use of sonication in degassing of liquids), reduces carbon dioxide solubility in the liquid, resulting in more gas coming out. Some of this is what forms the bubbles in the water, but more will simply add to the pressure of the gas as it escapes the liquid. This would be entirely consistent with the assertion the guys at the ACS makes that the pressure will not increase at equilibrium, since equilibrium will not be achieved for at least an hour after shaking... but my point is seconds after shaking, the pressure definitely increases. This seems plausible (and even testable, with the right equipment) to me... is it what happens shortly after shaking?