Overview

• The peer-reviewed work, published August 26 in Physics of Fluids, comes from teams at ETH Zurich and Eindhoven University of Technology.
• For single fermentation beers, foam stability is governed primarily by high surface viscosity at the bubble interface.
• In double-fermented beers, proteins assemble into elastic two-dimensional networks that keep thin liquid films intact longer.
• With additional fermentations, LTP1 breaks into surfactant-like fragments that drive Marangoni stresses and produce the most stable heads.
• Using interferometry and rheometry to directly visualize bubble films, the authors present beer as a platform to design greener surfactants and foam-control strategies for applications such as low-foaming EV lubricants, firefighting chemicals, oil separation, and some medical treatments.