most likely because soda tends to fizz more on dry, uneven surfaces.
Currently Pepsi.
pepsi
One way to demonstrate the fizz in soda is to connect balloons to the top of a soda bottle. The next step is to measure the inflation of the balloon to find "fizz". Then record your data.
frecsa
The fizz is put into soda by pumping carbon dioxide into it under pressure.
diet coke.
Cream Soda
yes
Carbon dioxide gas puts the fizz in soda water.
Baking Soda is most likely the answer to this question.
From my personal experience, Coca-Cola has had the most amount of fizz.