In my language (Russian) there are at least 3 words that can be used for the process of foam losing its volume (for example, in a beer mug) and going away. But none of the dictionaries I use give any kind of translation corresponding to those meanings of these words (regarding beer foam going away with time).
One of the problems is, as I see in the articles about beer foam, that the English internet suggests to either serve the beer without the foam at all or with little foam, and gives advice for that, or to remove it after serving if you fail. But what you would typically see in a Russian bar is a bartender pouring some beer in your mug, waitng a bit for the foam to lose some volume, then pour in more beer until the needed volume of the liquid is served, so I can't even find the word in the English articles about serving beer.
Anyway: how do I call the process of foam losing its volume, or waiting for it to lose the volume?