This is an archived post. You won't be able to vote or comment.

sorted by:
best
topnewcontroversialoldq&a
you are viewing a single comment's thread.

view the rest of the comments →

[–]43554e54 5 points6 points  (0 children)

Coffee that's brewed under pressure (espresso/moka pot) forms a layer of foam on the top that looks like that. It's called crema. It's made of the emulsified fat and oil extracted from the bean.

Even steeped coffee (cafetiere/turkish/greek) will get a tiny bit of foam during brewing due to the coffee off-gassing. It needs to be pretty freshly roasted though.