Thermodynamic properties of primary gushing of beer

Analytical Session
Guy S Derdelinckx, KU Leuven, Department of Microbial and Molecular Systems (M²S), Malt and Beer Sciences (MBS) and Leuven Food Science and Nutr
Co-author(s): Mohammadreza Khalesi, Sylvie Deckers, and Kurt Gebruers, KU Leuven, Department of Microbial and Molecular Systems (M2S), Malt and Beer Sciences (MBS), and Leuven Food Science and Nutrition, Belgium; Vladimir Ilberg, Hochschule Wei

ABSTRACT: Primary gushing of beer consists in overfoaming of beer out of the bottle. Nowadays, the mechanism of this phenomenon is rather well understood, and it is possible to tackle exact aspects of the explosion. The problem is studied by considering the volumetric and the barometric parameters of CO2, temperature, and shaking effects and their influences on the quantity of energy transferred to the bottle. By considering that the bottle opening at atmospheric pressure takes place under adiabatic conditions, that a closed beer bottle is an isochoric thermodynamic system, as well as that all the procedures take place at low pressure, the ideal gas law can be applied. With the theoretical calculation it could be shown why differences exist when applying the same methods at different analytical labs on identical malt samples. This is the case for results observed for gushing sensitive malt samples analyzed by the modified Carlsberg method The calculation model was tested for malt samples in order to determine an interval of confidence regarding the analytical lab conditions and the risks of industrial use of contaminated grains.

Guy Derdelinckx (1954) has been teaching specialized microbial aspects of barley, malt, and beer at KULeuven-Belgium since 2002. After obtaining an M.S. degree in tropical and subtropical sciences (1978), he successively obtains a master in brewing sciences degree (1979) and a Ph.D. degree (summa cum laude, 1985) on the flavanoid issue and boiling. After starting his professional work at the Université Catholique de Louvain, assuming the responsibility of the assay station, he became the scientific advisor for different Belgian breweries. He joined KULeuven in 1994 and for eight years he used his expertise internationally. In 2005, he went back to research and, more precisely, to exact science and focused his work, together with his research group and with the support of industry friends, on understanding the fundamentals of the mechanisms of beer gushing.