The Ingenious Design of the Aluminum Beverage Can

This video also let me to this one: https://www.youtube.com/watch?v=K-Fc08X56R0 explaining that no matter how much you shake the soda can or bottle, the pressure inside remains stable (3 atm).

Once you open it after shaking however, it's the chain reaction of CO2 coming out of solution around the bubbles you introduced, not the pressure.

So if you have a shaken up can. just tap it gently to remove the bubbles stuck to the sides before opening.