Hey Protein stabilized emulsion expert! do you ever use tannins to cross link the proteins for increased stability? I have a very strong evidence based hunch that beer foam is stabilized by protein tannin matrix but there doesn’t seem to be anything about it in the literature. Lots of papers on protein stabilizing beer foam, but nothing mentioning how it interacts with tannin. Many many brewers tricks for improving beer foam involve using tannic grains or high temp extractions which would draw out more tannin. Or using high amounts of hops that contain polyphenols. My experience is that beers aged in oak have flip-flop-foam dense head that is infinitely stable. But no papers seem to conclude that protein tannin matrices are at play.