Prediction of Colloidal Stability of Highly Stabilized Beers by a Modified Chapon Tannoid Content Test

Abstract

The tannoid content test, introduced by Chapon, is accepted as a recommended MEBAK analytical method for the detection of haze-forming polyphenols in beer and other intermediates. Under certain conditions, the results can be used directly for predicting the colloidal stability of beer. Its disadvantage is that it does not provide detectable results for beers stabilized by high doses of polyvinylpolypyrrolidone (PVPP). A test modification is proposed that increases the test sensitivity and gives non-zero results, even for highly stabilized samples that are not measurable by the standard test. The modification is based on adding saturated ammonium sulphate solution (SASS) to the sample to reach 9% saturation (0.5 mL of SASS to 5 mL sample volume) before the actual test performance. The results of the modified test can simply be converted to results obtained by the standard method. Tannoid content correlates linearly with the content of haze-forming polyphenols and with chill haze produced after defined accelerated aging. In a set of beer samples of one brand having different degrees of stabilization, a high correlation was determined between test results and long-term colloidal stability. The modified test can be used as a rapid and simple test for checking the stabilization process. It is particularly suitable for Pilsner type beer of long (more than 6 months) colloidal stability controlled by stabilization on the side of polyphenols.

A new rapid high-throughput method for prediction of beer colloidal stability

“…A 0.2 g/L solution of tannic acid (prepared fresh daily) was prepared for conducting the test for sensitive proteins. A sensitive proteins test was performed according to EBC–Analytica , and a tannoid content test was performed according to a modified procedure by pre‐dosing the sample with saturated ammonium sulphate .…”

“…A special category of precipitation tests are nephelometric titration tests. These tests include a test on the content of Chapon's tannoids , its modifications and the test of the content of sensitive proteins . Nephelometric titration tests belong to methods that measure directly the content of beer haze precursors.…”

Practical Experience with Installation of Beer Stabilization in Operation.

“…Commonly, 0.5 ml of SASS is added to 5 ml. This highlights the maximum of haze turbidity, but protein precipitation is not initiated (Gabriel, 2009Dienstbier et al, 2011. kalotvorných složek a vytváří zákal, který se detekuje zákaloměrem.…”

“…Do 5 ml se běžně přidává 0,5 ml SASS. Tím dojde ke zvýraznění maxima zákalu, ale zároveň ještě není vyvoláno srážení proteinů (Gabriel, 2009, Dienstbier et al, 2011.…”