Boiler feed water for use in the production of beer and other foods
Copper forms a complex with sodium diethyldithiocarbamate with a maximum absorption at 436 nm.
If the copper content is high, turbidity will result. In such cases, the water sample must be diluted. The method is suitable for water with a copper content up to 1 mg/l. An extraction must be performed in order to determine extremely low concentrations of copper.
This method describes how to determine the iron content of boiler feed water. Iron can cause surface deposits to develop.
Boiler feed water for use in the production of beer and other foods
Fe(III) ions form a complex with sulfosalicylic acid, which is red in an acidic solution and yellow in an alkaline solution. Since Fe(II) ions are oxidized in an alkaline solution, they are detected as well. In this way, the value for total iron can be measured.
This method describes how to determine whether kernels are cracked as part of the visual and manual inspection of a lot of barley.
Barley intended for the production of malt is to be evaluated on the basis of the characteristics described below.
Visual assessment
This method describes how to determine whether a lot of grain is contaminated with ergot visually through manual inspection.
Barley intended for the production of malt; therefore, the kernels are to be evaluated on the basis of the characteristics described below.
A representative sample of grain is visually inspected for the presence of ergot sclerotia.
This method describes how to determine not only the variety of barley but whether a lot of barley consists of a mix of varieties.
Barley intended for malt production as well as barley malt
Separation and identification of the protein (hordein) fraction of barley or barley malt by means of gel electrophoresis. The method is suitable for all types of barley, as long as reference substances are available. However, the method cannot be used to identify barley varieties used to produce malt that has been so strongly modified that the protein fraction is almost completely degraded.
Hops and hop products intended for use in beer brewing or elsewhere in the food industry
Hop constituents are distributed between an aqueous acidic methanolic phase and diethyl ether. Hop bitter substances extracted with ether are subsequently separated according to their different solubility properties in cold methanol and hexane into fractions: total resins, soft resins and hard resins. The soft resins are further separated according to their capacity to form complexes with lead salts into α-acids (conductometer value) and a β-fraction.