/ RAW MATERIALS / Malt / Gushing

R-200.31.020 [2022-03] Gushing Tendency in Malt and Adjuncts – Modified Carlsberg Test

Gushing, also known as fobbing, is a problem that has been linked to multiple sources, including Fusarium infection in grain used in the production of beer. After comprehensive research on raw materials spanning many years, no single substance has yet been identified in a measurable quantity in malt infected with Fusarium, which can clearly be linked to gushing behavior in the finished beer.

Current research is exploring different groups of substances (proteins and hydrophobins) that are present in greater quantities in kernels infected with Fusarium [1].

In reproducible laboratory tests as well as in commercial beers, it has been proven that porous or sharp-edged particles (approx. 1–10 µm in diameter) such as calcium oxalate, calcium carbonate, crystallized dextrins as well as filter aids (diatomaceous earth/kieselguhr, perlite, activated charcoal) can cause gushing if present in certain concentrations [2]. Additionally, poor glass quality (rough interior) can also bring about gushing. Furthermore, the carbon dioxide concentration and the size of the gas bubbles also influence gushing behavior [3].

Research has shown that the reproducibility of the results varies over a wide range [4], so that no data for r and R can be given.

References

L. Winkelmann, BWelt 25, 749–751, 2004
M. Zarnkow, W. Back, BWelt 9/10, 363–370, 2001
S. Fischer, Schlussbericht für das Forschungsvorhaben R 314 der Wissenschaftsförderung der Deutschen Brauwirtschaft e. V., 9–11, 2000
A. Haikara, T. Sarlin, S. Home, J. Inst. Brew. 111, 247, 2005

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amount of beer lost to gushing

gushing potential

gushing tendency

MCT

Application/Purpose

This method describes how to determine the gushing potential of a sample to be analyzed.

Scope of Application

Malted and unmalted grain intended for use in beer brewing or elsewhere in the food industry

Principle

A cold water extract of a malt or adjunct (coarse grist) is concentrated through boiling; subsequently, standardized bottled water is added to the extract. The extract is filled in bottles. After the bottles have been shaken according to a defined procedure, they are opened and the weight of liquid fobbing out of the bottles as foam (gushing) is determined and taken as a measure of the gushing potential for the malt or adjunct in question.