It seems like every time I pour a cup of diet Pepsi, it's flat well before I even get half done with it. Regular soda stays nice and bubbly until I'm done....hell, I've even left a can of Coke open on my nightstand and drank it in the morning and it was fine, a bit warm but fine and yummy.
IIN diet sodas go flat ultra fast? So annoying.
IIN diet sodas go flat ultra fast? So annoying.

And now I'm stuck because sugars are simple isomers and in no way large enough to act as condensation nuclei, so the absence of sugar doesn't imply the absence of fizz.
I don't know, OP. You've stumped me! And now I am going to obsess about this until I ask one of the Professors at work.