Independence of Malting Quality and Barley Flour Particle Size. Charles W. Baker and Ayed S. Amr, North Dakota State University, Fargo, ND 58102. J. Am. Soc. Brew. Chem. 36:0087, 1978.

A recently published sedimentation-nephelometric procedure (28) was not applicable for screening the malting potential of American six-row barleys. Sedimentation behavior was influenced more by mill than variety. The highly significant difference between replications negated the use of supernatant turbidity as a measure of malting quality. The relation between milling characteristics of 60 six-row barleys used in this study and malting performance was investigated. Kernel plumpness increased with increasing abundance of small particles, but decreased with increasing number and/or protein content of large particles. Malt recovery increased with increasing number of small particles and decreasing number and/or increasing protein content of large particles. Malt protein increased with increasing protein content of all particles, while wort protein increased with increasing protein level of large particles. The ratio of wort protein to total protein decreased as the protein content of small particles increased. Coarse grind extract decreased with increasing protein content of small particles. Diastatic power increased with increasing protein level of large particles. α-Amylase increased with increasing number and/or protein of large particles. Taking all data into consideration, milled particle size is not an accurate indicator of malting potential.

Keywords: Barley, Malt, Milling, Particle size, Sedimentation.