Overview

• Triple‑fermented beers showed the most stable heads, double‑fermented were intermediate, and single‑fermented lagers were least stable.
• Single fermentations stabilize foam mainly through surface viscosity, double fermentations form elastic two‑dimensional protein networks, and triple fermentations rely on Marangoni stresses from surfactant‑like protein fragments.
• The barley protein LTP1 was identified as the decisive molecule, with yeast‑driven changes across fermentations shifting it from particles to nets to amphiphilic fragments.
• Researchers directly visualized the thin films between bubbles using advanced imaging and rheometry in a seven‑year ETH Zurich–Eindhoven University study published in Physics of Fluids.
• The team is advising a major brewery and collaborating with Shell, noting the findings can help tailor beer heads and address industrial foaming while guiding greener surfactant design.