The foam in beer, which people either love or hate while drinking, has unexpectedly become the key to solving a core pain point of new energy vehicles. According to the latest industy news, scientists from ETH Zurich have spent 7 years studying the foaming and defoaming mechanisms of beer foam, accidentally providing a breakthrough solution to the foam problem in electric vehicle (EV) motor lubricating oil. Relevant achievements have already attracted collaborations with giants like Shell for the development of specialized lubricants.
EV motors operate at speeds of tens of thousands of revolutions per minute, far exceeding those of traditional gasoline vehicle engines. Under high-intensity stirring, the lubricating oil and cooling fluid inside the motor easily trap air, generating a large number of tiny bubbles. These bubbles are tantamount to “invisible killers” for EVs: they not only hinder heat dissipation, leading to motor overheating and power reduction, but also break down the protective oil film between gears and bearings, causing increased wear, pitting corrosion, accelerated oil oxidation, and shortened oil change intervals. Previously, automakers and manufacturers attempted solutions such as adding defoamers and modifying oil circuits, but with limited success.
Scientists observed significant differences in foam stability across different beers—for example, the foam of Belgian craft beers can last for over ten minutes, while that of some other beers dissipates in an instant. To uncover the root cause, they collaborated with a local brewery and employed advanced techniques including high-precision microscopic imaging and proteomic analysis to systematically study changes in protein structure during beer fermentation and the deformation of bubbles under stress. Ultimately, they identified two key factors: the protein LTP1 and the Marangoni effect.
The research revealed that the stabilization mechanism of beer foam is far more complex than previously thought. For lagers (beers fermented at low temperatures, 10-12°C, with bottom-fermenting yeast and aged), foam stability primarily relies on the increased viscosity of bubbles induced by LTP1—the higher the viscosity, the more resistant the foam is to breaking. For double-fermented beers, a thin film or network structure forms on the bubble surface, with stability relying more on structural support than surface viscosity. In triple-fermented Belgian beers, LTP1 is completely degraded into fragments with hydrophilic and hydrophobic ends; these fragments actively reduce surface tension, and the resulting Marangoni stress significantly slows foam collapse.
To visualize this: imagine each bubble as a fragile “balloon”—gravity pulls the liquid downward, thinning the balloon wall (liquid film) and making it prone to bursting. LTP1 acts like steel reinforcement in the balloon wall, while the Marangoni effect functions as an automatic repair team that strengthens thin areas without sacrificing others. When a section of the bubble wall thins and surface tension changes, the Marangoni effect drives surrounding liquid to flow to the weakened area, “patching” it up. (This effect also explains the “legs” of wine.)
Building on these findings, lubricant giants have launched collaborative projects to formulate EV-specific lubricants that precisely target and disrupt foam stabilization mechanisms. Beyond lubricants, the research has potential applications in fire-fighting foams, oil-water separation, and even medical sclerosants for treating varicose veins. This scientific exploration, born from studying beer foam, not only unlocks the physical and biological mysteries behind a common beverage but also delivers cross-industry innovative ideas to the new energy vehicle sector. In the future, car owners may indirectly benefit from the insights gained from craft beer research during their drives.
