Kvasny Prum. 1999; 45(6): 156-159 | DOI: 10.18832/kp1999011

The new method of objective providing of beer tests with ammonium sulfate in standard chemical test tubes.Peer-reviewed article

P. SLADKÝ, H. CÍSAŘOVÁ

The new method of projective determination of precipitation threshold of beer colloids with saturated solution of ammonium sulfate is described. It is based on intensity measurement of nephelometric turbidity of sample in standard chemical test tubes in dependence on titrator quantity dosed step by step and stirred by standard micropipette provided with piston agitator. For evaluation of test there is introduced a precise analytical definition of precipitation threshold of beer with ammonium sulfate, respectively other titrators, based on tangential determination of threshold concentration necessary for colloid precipitation of sample.The described method enables significant increasing of measurement productivity and multiple reducing of both analyte and material costs, simultaneously by increasing precision of precipitation threshold determination, even by means of manual record of monitored data, which enables using so called sulfate test in small breweries as well. The described method is possible to automate by means of adaption of suitable brewery laboratory turbidimeters to measurement in test tubes and their connection to personal computer of standard type and so further increase analytical efficiency in large breweries.
(In Czech, English summary only)

Keywords: beer, colloidal stability, haze, sulfate test

Published: June 1, 1999