The method describes aseptic working conditions in a laboratory.
Laboratories in the beverage industry in general and the brewing industry in particular.
The aim of aseptic techniques is to protect sterile culture media, solutions and devices as well as pure cultures of microorganisms from contamination and to eliminate false-positive and false-negative findings.
This method describes how to determine the gushing potential of a sample to be analyzed.
Malted and unmalted grain intended for use in beer brewing or elsewhere in the food industry
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.
This method is suitable for the determination of steam-volatile aroma compounds in wort.
Volatile aroma compounds are driven out of the sample through steam distillation. The ethanol distillate is adjusted to be alkaline and saturated with NaCl. The extraction of the aroma compounds is performed by shaking out with dichloromethane and the phases separated by centrifuging. The organic phase is further concentrated in a stream of nitrogen gas. An ammonia solution is added to remove the acids, because the acids would co-elute, thus preventing quantification of the target substances.
If a water sample is run through a strongly acidic cation exchanger, all of the cations are replaced with hydrogen ions, thus producing the corresponding free acids in equivalent quantities (total mineral acid value). Since the carbonates and bicarbonates are transformed into carbon dioxide and therefore escape determination, their content must be determined through titration with acid to a pH of 4.3 (m value).
This method describes how to calculate the concentration of sodium and potassium ions in water.
Since analyses for determining the concentrations of sodium and potassium ions in water require considerable effort, and these ions are not very relevant for evaluating the suitability of water for the processes of brewing and malting, a simple calculation will suffice. The difference in the concentrations of anions and cations in the water is determined, allowing the calculation to be performed under the assumption that only sodium ions are present in the water.
The method is suitable for the determination of water vapor volatile aroma compounds in beer.
Volatile aroma compounds are driven out of the sample through steam distillation. The ethanolic distillate is saturated with NaCl. Potassium hydrogen sulfite is added to separate carbonyl groups that might interfere with the analysis. The extraction of the aroma compounds is performed by shaking out with dichloromethane and the phases separated by centrifuging.