Table of Contents
Rapid method to assess the colloidal haze stability of beer
M. Kupetz, M. Frankerl, M. Gastl and T. Becker
Due to a rising globalization in food and beverage industry, consumers expect a long chemical-physical beer stability without an appearance of haze. The analysis of the chemical-physical stability, however, often represents a long process when the classic forced aging test is applied. In comparison, alcohol-chill or formaldehyde test can be performed in a shorter analysis time, but barely gives information on the real beer stability. For this reason, the aim of this work was to develop a rapid measurement method determining colloidal stability. To accelerate the haze formation, an oxidizer was added into beer and 3 temperature changes of 0 and 60??C were carried out. An optimal amount of 1?mL hydrogen peroxide per 500?mL beer (0.06?%) was determined. After 26?h, the haze increase could be examined using a scattering light angle measuring device. The comparison of this haze increase and the warm days of the classic 0/60??C forced aging test resulted in an exponential function with R2 = 0.87 (n =3 8, samples of 10 breweries), whereas 3 non-stabilized beer samples had significantly higher haze increases. Furthermore, stability could be classified comparing warm days and haze increase in low stability (0 ? 4 warm days): > 1 EBC haze increase, medium stability (5 ? 8 warm days): 0.1 ? 1 EBC haze increase and high stability (above 8 warm days):
Descriptors: colloidal stability, beer stabilization, forcing test
BrewingScience, 72 (Juli/August 2019), pp. 141-146
