Hey there!
Thanks for watching the video and coming to check these out. A number of these are not easily available or are behind paywalls. Sci Hub (which I’m not going to link to here) is an option.
I’d recommend starting with this paper, as it is a great overview with tonnes of links to other papers:
Neglected Food Bubbles: The Espresso Coffee Foam
This was my starting point, and the references alone should keep you busy. For more:
Rheological interfacial properties of espresso coffee foaming fractions (pdf)
Understanding the Formation of CO2 and Its Degassing Behaviours in Coffee (pdf)
There were three papers I bought from ASIC, and annoyingly I don’t think I can share them. I’ve asked about sharing them, and will update if I hear back. They aren’t really available anywhere I’ve found (like Sci Hub)
Espresso Coffee Brewing Dynamics : Development Of Mathematical And Computational Models
Impact of Crema Quantity and Appearance on Actual Coffee Perception
Physicochemical Characterization of the Espresso Coffee Foam
Share anything interesting you find in the comments below!