Kvasný průmysl (May 2004)
Measurement of HGB beer colloidal ageing and tannoid content development using complex turbidimetric analysis.
Abstract
Measurements of HGB beers were carried out in concentrated and blended samples to analyse the chill haze and tannoid content development during the thermal forced ageing process. The measurements were performed by the method of complex turbidimetric analysis (CTA), based on a single instrumentation for beer chill haze determination in commercial bottles and polyvinylpyrrolidone/tannoid content titration of beer samples in usual reaction tubes. For illustration of the efficiency of the CTA method, the initial values of saturated ammonium sulphate precipitation limits (SASPL) and sensitive protein (SP) levels were determined, too. The CTA method confirmed enhanced colloidal stability of the blended HGB final product due to lower content of the high molecular weight haze active proteotannic complexes. An almost linear correlation between the chill haze and tannoid content development during beer ageing process, starting from some concentration threshold level after a certain lag time was revealed.The correlation between the tannoid content of HGB beer in blended and non blended state was found also linear. The CTA method can be effectively used for the evaluation and prediction of the HGB beer colloidal ageing process and diagnostics of the causes of production inhomogeneity.Measurements of HGB beers were carried out in concentrated and blended samples to analyse the chill haze and tannoid content development during the thermal forced ageing process. The measurements were performed by the method of complex turbidimetric analysis (CTA), based on a single instrumentation for beer chill haze determination in commercial bottles and polyvinylpyrrolidone/tannoid content titration of beer samples in usual reaction tubes. For illustration of the efficiency of the CTA method, the initial values of saturated ammonium sulphate precipitation limits (SASPL) and sensitive protein (SP) levels were determined, too. The CTA method confirmed enhanced colloidal stability of the blended HGB final product due to lower content of the high molecular weight haze active proteotannic complexes. An almost linear correlation between the chill haze and tannoid content development during beer ageing process, starting from some concentration threshold level after a certain lag time was revealed.The correlation between the tannoid content of HGB beer in blended and non blended state was found also linear. The CTA method can be effectively used for the evaluation and prediction of the HGB beer colloidal ageing process and diagnostics of the causes of production inhomogeneity.
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