The moisture content of barley must be determined prior to its storage.
Determination of the moisture content of barley is carried out according to ISO 712, 2009, i.e., milled barley is dried at a defined temperature within a set time period in an electrically heated air-drying oven.
The moisture content is calculated through the difference in mass prior to and after drying.
Barley with moisture contents above 17 % must be pre-dried as whole kernels prior to analysis. This method is not suitable for malt.
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.
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.
Prior to storage, the moisture content of barley must be determined.
The sample is heated directly on the weighing pan in the drying chamber using microwaves. The water evaporates and is removed by a compressor. In order to avoid disturbing the weighing process as little as possible, the sample is protected from the flow of gas by a porous cover. The change in weight is measured directly; after a constant weight is reached, it is evaluated.
With microwave-vacuum drying, the vaporization temperature is lowered, resulting in a more gentle drying process. Additionally, the samples are under constant rotation to prevent degradation and burning of the sample.
Malt intended for use in beer brewing or elsewhere in the food industry
The moisture content of malt is determined through the loss in mass during a standardized drying process, in which ground malt is dried at a defined temperature within a specified time in an electrically heated drying oven. The moisture content is determined through the difference in the weight of the malt prior to and after drying.
It should be borne in mind that allowing the weighed sample of ground malt to stand for any length of time prior to performing the analysis can alter the outcome, depending upon the humidity in the air. For this reason, it is recommended that the analysis be carried out immediately after grinding the malt.
For rapid methods, refer to analysis methods R-110.40.022 Moisture Content in Barley – Infrared Drying to R-110.40.183 Moisture Content in Barley – NIT (Verweise).
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.