Why does soda from a fountain have less fizz than soda from a bottle?

Tempature is the real culprit here .The average temp of the beverage from a soda fountain is 38-40 f.Once that warmer drink touches the colder ice at 32f ,it releases carbonation faster,A tip to better carbonation from a fountain is to not let the beverage pour directly over the ice,tilt your cup slightly and let it pour down the wall of the cup.This will give you much mor crisp and tastier beverage.  more