eli5 – why does tapping the top of a pop can make it fizz less? Or is that just a myth I’ve been practicing for 30+ years?

Question

What the title says. Pop means soda btw.

In: 1560

Answer 1

When you shake a can, you make tiny bubbles. Those bubbles are under high pressure. When you open the can, the bubbles get bigger because there’s no pressure keeping them small. Big bubbles break up into a ton of small bubbles, and all the co2 still stuck in the soda really likes to stick to the small bubbles, making them bigger, which makes a chain reaction.

When you tap the can, those tiny bubbles that were stuck to the sides of the can pop off the sides and float to the top of the can. Then, when you open the can, instead of making big bubbles that co2 can stick to and grow the bubbles even more, they just pop, so there’s no bubbles for the co2 to stick to and escape the soda.