New ways to systematically characterize beer foam

The question of whether and how much foam should be on a glass of beer, what this foam should look like and how quickly it should disintegrate is a question of taste – or even of culture, in view of the different national ideas of perfectly served beer. Which mechanisms and effects are responsible for all these foam properties is primarily a question for surface research, as foam is created by surface-active substances. Until now, however, there has been a lack of standardizable measurement procedures and methods for sample preparation in order to reproducibly find correlations between foam formation and surface tension and its dynamics.

A group from the Technical University of Munich and KRÜSS has now published a methodology for systematic foam analyses of carbonated beverages. Using the beer types Pilsner, Kölsch, and wheat, the scientists developed preparation procedures for comparable initial conditions and worked out test parameters – for example foaming with different gases – with the help of which they could systematically correlate foam properties and surface-physical measured variables.

The DFA100 Dynamic Foam Analyzer used in the study foams liquids with a precisely controlled gas flow and records a large number of time-dependent foam parameters, including its bubble structure, with particular precision. Analyses of the same samples with a BP100 Bubble Pressure Tensiometer characterized the changes in surface tension over time. The investigations were completed with interfacial rheological measurements using a DSA30R Drop Shape Analyzer, which records the reaction of the surface to its dilatation – a behavior that can be transferred to the stability of foam lamellae.

The results show a way to comprehensively characterize the foaming behavior of carbonated beverages and to precisely work out the influences of the respective recipes on foam formation by standardizing the measurement methods.

Read the study and find out more about the results and the preparation and measurement methods:

J. Dombrowski, D. Frese, S. Benn, U. Kolozik, Thomas Willers: Methodological approach to characterize the interfacial and foaming properties of carbonated beverages. Journal of Dispersion Science and Technology, 2024.
DOI: 10.1080/01932691.2024.2417678