Oh, sorry, my bad:)

In his readme, he says:

"Sorry for not making one layered shader
but two separated SGs.
It's easily transformed into one for using it
on only one object, but if you...

I havn't been able to take a good look at that coffee shader at highend, but I believe it is a layered texture or shader, and comes with a "bubbly" image that goes on top. ( I think)

...at least,...