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
For determination of the dry residue in water after filtration, a certain quantity of filtrate is evaporated until dry. It is subsequently dried in a drying oven to eliminate any remaining moisture.
Prior to storage, the moisture content of barley must be determined.
The classic procedure performed using a drying oven is very time-consuming. Drying with infrared radiation significantly shortens the time required for drying, since the barley to be dried is immediately penetrated by the infrared radiation, which gives off a part of its energy, thereby heating the barley. With infrared drying, an adjustable heat source is connected to an electronic balance. The loss in mass during drying is continually recorded by the balance. The apparatus is equipped with a built-in microprocessor, which allows it to be programmed with data which was collected empirically with regard to optimal drying conditions.
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).
Determination of the soluble dry matter by means of a refractometer
non-alcoholic beverages, juices
The quantity of soluble dry matter is determined refractometrically. This is related to the percent by weight of sucrose in an aqueous sucrose solution, which under defined conditions possesses the same refraction index as that of the product being analyzed. The amount of soluble dry matter is expressed in g per 100 g of solution. The refraction index is not determined directly for non-alcoholic soft drinks, but rather by means of a scale based on the percentage of sucrose by weight (°Brix). Since the °Brix scale uses sucrose, correction factors for other sugars must be taken from tables for each individual type of sugar. The presence of other substances, such as organic acids, minerals and amino acids, has an effect on the refraction index of a product. Due to the high acidity of citrus juices and citrus juice concentrates, correction factors are also necessary for measuring their °Brix values.