Search: gushing potential

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.

A sample is collected of the cereal to be tested and a hot water extraction is carried out. After cold break separation, the sample is carbonated and bottled. After shaking and then opening the bottle, the volume of liquid that fobs over and out of the bottle is measured. This value is used to determine the gushing potential for the malt or adjunct.

Visual evaluation

A relationship is suspected to exist between the metabolic by-products of Fusarium graminearum and Fusarium culmorum and the phenomenon of  primary (malt-related) gushing. Furthermore, the upper limits for mycotoxins found in grain products have been established and are subject to regulations in Germany and the rest of Europe. Current limit values can be obtained from www.deutsches-bier.net or info@brauer-bund.de. Fusarium species form a red pigment which leads to noticeable red discoloration of contaminated malt kernels. However, other types of fungus, in addition to Fusarium species, are also able to produce red pigments. Therefore, a differentiation among the red kernels should be performed. 

Iron is measured using the AAS technique by directly aspirating the diluted sample into an acetylene oxygen flame or electrothermally (graphite furnace); the measurement is made at 248.3 nm.

Calcium in wort is measured using AAS by directly aspirating the diluted sample into a nitrous oxide-acetylene flame; the measurement is made at 423 nm.

Lanthanum chloride reduces interference.