This method describes how the protein content in adjuncts is determined.
The nitrogen/raw protein content of barley intended for the production of brewing malt must be determined in advance.
The sample is combusted in a pure oxygen atmosphere at approx. 1000 °C. The resulting mix of gases comes into contact with a CuO/Pt catalyst and is thereby completely oxidized and subsequently freed of all by-products which could potentially interfere with analysis.
After the nitrogen oxides formed in the combustion process are reduced upon contact with tungsten, all nitrogen compounds in the sample are reduced to elemental nitrogen (N2). The elemental nitrogen is then detected by means of a thermal conductivity detector (TCD), the signal of which is quantitatively evaluated by a dedicated integrator.
This method describes how to determine the total nitrogen content by means of the combustion method according to Dumas.
Malt intended for use in beer brewing or elsewhere in the food industry.
Suitable for all (laboratory) worts
Wort is produced using a laboratory mash method (fine grind) after which the nitrogen content of the wort is determined.
Automatic determination of total nitrogen using catalytic combustion in wort and beer.
This method is suitable for wort and beer.
The sample is burned in an oxygen-rich atmosphere at approximately 1000 °C, producing nitrous oxides, which are catalytically reduced to elemental nitrogen. Other combustion products are eliminated by means of selective absorption.
The elemental nitrogen is measured with a thermal conductivity detector, which has been calibrated using a known nitrogen standard.
These automatic combustion devices require a carrier gas, e.g., helium or carbon dioxide.