USE OF THE HAGBERG FALLING NUMBER APPARATUS TO DETERMINE MALT AND BARLEY QUALITY

Abstract

The Hagberg Falling Number measurement, widely used in the milling industry for assessing the baking quality of wheat flour, has been modified and used as a rapid mashing technique to assess malt quality. Barley Malt flour is mixed with cold mashing liquor containing 0.1% calcium chloride and 15 mM beta‐mercapto‐ethanol. The slurry is heated and mixed by the Falling Number apparatus, and the starch is gelatinized. After one minute of heating/mixing the stirring rods are raised and released. As the gelatinized starch is hydrolysed by amylases, the viscosity of the slurry decreases allowing the stirring rods to fall. The time taken for these rods to fall a fixed distance is called the Falling Number. A relationship has been determined between the Falling Number obtained for a malt and the quality of the malt. Poor quality malts had a high Falling Number (e.g. >200s) whilst good malts had a low Falling Number (e.g. <150s). The correlation coefficient between Falling Number and Hot Water Extract (IOB coarse grind) was −0.89, and between Falling Number and Friability was −0.96. These good correlations indicate the measurement was influenced by the degree of endosperm modification. Being a mashing technique, however, the Falling Number was also influenced by other factors which influence mashing such as enzyme complement and water binding. This technique has the potential to measure malt quality using a commercial apparatus more rapidly than present malt analyses. No significant relationship could be determined between the Falling Number and the malting quality of barley. 1991 The Institute of Brewing & Distilling