Theory 134/Beer foam/Threshold lens
Stability Needs Protein
The claim
Foam persists only above a threshold in the ratio of hydrophobic protein to lipid, so trace fat destroys foam that protein would hold.
01Mechanism
Proteins stabilise bubble walls while lipids displace them; the ratio determines whether the film survives.
02Prediction
Stability should track the ratio.
03Refutation
Stability tracking protein alone would remove lipid.