You'll notice a difference right away, because the escaping CO2 breaks the head on the beer, which is exactly the opposite of what you want on a pilsner. As for

You'll notice a difference right away, because the escaping CO2 breaks the head on the beer, which is exactly the opposite of what you want on a pilsner. As for going flat, I'd have to root around on Brulosophy later I think they did a test on this.