ETH reveals the secret behind perfect beer foam
27.8.2025
Translation: machine translated
Belgian Trappist beers keep their crown, lagers lose it quickly. ETH researchers show: The difference lies in a protein.
The protein is called LTP1 and behaves very differently depending on the brewing method. In lager beers, it remains stable and wraps itself around the foam bubbles like a protective shell. This keeps them in shape for a brief moment, then everything collapses.
More complex beers undergo a second or even third fermentation. This changes the protein: it cross-links, becomes more stable and keeps the foam longer. In the third fermentation stage, it finally breaks down into tiny fragments. They act like surfactants and have a water-loving and a water-repellent side, thus stabilising the bubbles. It is precisely this structure that gives Belgian Trappist beers their legendary resilient crown.
There is far more science between hops, yeast and foam than you might think. And anyone who looks at the crown of their next Belgian beer will now know that this is not just the art of brewing, but also protein physics at its finest.
Header image: EeCie / Shutterstock
