Water intended for use as an ingredient in the production of beer (brewing liquor) or other foods
A specified quantity of water is evaporated, and any remaining moisture is subsequently eliminated in a drying oven. The dry residue is then weighed.
Determination of hydrogen peroxide (H2O2) in disinfectants.
Suitable for all solutions that contain hydrogen peroxide (H2O2) but do not contain any other peroxides.
The quantitative determination is carried out in a sulphuric acid solution by titration with potassium permanganate:
5 H202 + 2 KMnO4 + 3 H2S04 → 2 MnSO4 + H2S04 + 8 H20 + 5 02
If the sample contains other peroxide-containing disinfectants in addition to hydrogen peroxide (H2O2), the method T-754-01-032 Peracetic-acid-based-disinfectants must be used.
The method provides an estimate of the portion of pre-germinated barley grains at the time of harvest or prior to storage in silos.
Barley intended for the production of malt is evaluated with regard to pre-germination.
The onset of germination is accompanied by the synthesis of enzymes, which can be made visible using fluorescein dibutyrate (FDB). The reagent fluoresces in the presence of lipases.
In order to make the enzyme activity visible, the kernels are first split in half and coated with the FDB reagent after which they are examined in a suitable measuring device under UV light. An intense yellow fluorescence can be seen in the parts of the kernels where enzyme activity is present.
This method describes how to determine the extract content of malt used to produce laboratory wort.
Malt intended for use in beer brewing or elsewhere in the food industry
The extract content of malt refers to the compounds from finely ground malt (fine grind), which are brought into solution during a standardized mashing process.
The extract content is determined by the weight ratio sL 20/20 of the wort on the basis of the official sugar tables (Plato tables) at 20 °C. sL 20/20 stands for the weight ratio of a volume of wort at 20 °C to the same volume of water at the same temperature.
Malt intended for use in beer brewing or elsewhere in the food industry
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.