Why does pouring beer onto the sides of the glass prevent it from foaming, as opposed to pouring it straight down the middle?

Question

Why does pouring beer onto the sides of the glass prevent it from foaming, as opposed to pouring it straight down the middle?

In: 83

Answer 1

Agitation is well known to cause beer to foam. You just don’t give a beer a good hard shake and pop the lid right off, it will spew all over the place.

Pouring gently down the side of the glass reduces the amount of turbulence in the beer and reduces foaming.

I, for one detest this practice. Draft beer served in a bar is supposed to have a head on it. I pour a bottled beer gently right down the middle to get that head where it belongs.