Determination of the vicinal diketone content (diacetyl + 2,3-pentanedione) as well as the total diketone content in beer
The method is suitable for filtered beers brewed to any original wort or to any alcohol content as well as for fermenting wort.
Diacetyl (2,3-butanedione) and 2,3-pentanedione are detected photometrically in the beer after steam distillation. It is also possible to determine precursors in green beer.
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.
Whole hops intended for use in beer brewing or elsewhere in the food industry
Evaluation of the appearance of hop cones is performed through visual inspection and sensory assessment.
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).
Applicable for all (laboratory) worts
The Congress wort is heated in order to inactivate the amylolytic enzymes, and afterwards, yeast is added and the wort is allowed to completely ferment out at a minimum temperature of 20 °C in a fermentation tube (fig. 1). The difference in the extract before and after fermentation is measured in order to calculate the limit of attenuation.
This method describes how to calculate the magnesium ion content of water.
Magnesium ions are calculated by subtracting concentration of calcium ions (W-000.17.031 - Calcium in Wasser, Komplexometrische Bestimmung mit EDTA) from the total hardness (W-000.11.031 - Gesamthärte in Wasser).