LTP1 proteins govern foam stability across beer fermentations

A team of European researchers has identified the degree of fermentation as a key determinant of beer foam stability, concluding that single, double and triple fermentation produce qualitatively different protein structures at bubble surfaces and, in turn, markedly different foam lifetimes. After roughly seven years of experiments combining advanced imaging and rheometry, the group found that triple-fermented Belgian-style beers produced the most long-lived heads, while single-fermented lagers yielded the least stable foams. The findings were published in the journal Physics of Fluids.

The researchers focused on the thin liquid film that separates adjacent bubbles in foam, using techniques that allow direct visualization of protein aggregates and interfacial structure as bubbles come into close proximity. Emmanouil Chatzigiannakis, an assistant professor involved in the work, said that beer offered an ideal experimental platform. "The idea was to directly study what happens in the thin film that separates two neighbouring bubbles," he said. "We can directly visualize what is happening, and see the bubbles' protein aggregates, their interface and their structure."