Czech J. Food Sci., 2009, 27(3):158-164 | DOI: 10.17221/156/2008-CJFS

The effect of the barley variety, location and year crop on the haze of congress wort

Vratislav Psota¹, Zuzana Skulilová², Jiří Hartmann³

¹ Research Institute of Brewing and Malting, PLC, Malting Institute, Brno, Czech Republic

² Department of Food Technology, Faculty of Agronomy, Mendel University of Agriculture and Forestry Brno, Brno, Czech Republic

³ Central Institute for Supervising and Testing in Agriculture, Brno, Czech Republic$2

The study set consisted of eleven barley (Hordeum vulgare L.) varieties grown at four different locations for a three-year period. The malting characteristics were determined in all samples. The results obtained using the traditional visual evaluation of wort clarity were compared with those obtained nephelometerically. The results indicate a considerable effect of a variety on the wort haze (30-40%). The effect of location on the wort haze varied from 13-22%, the effect of year was small. The level of wort haze or wort clarity split the set of the varieties under study to clearly distinguishable groups. The worts from the varieties Annabell and Nordus inclined to form wort haze. Statistically significant or highly significant correlation was found between the wort haze and clarity and the relative extract at 45°C, diastatic power, final apparent attenuation, and saccharification time. The relationship between the wort haze or clarity and other technological parameters was not statistically significant in most cases. The correlation coefficient between the haze at 15° or 90° (nephelometric method) and wort clarity (visual method) was 0.89. The nephelometric determination of wort haze completely replaces the traditional subjective evaluation of wort clarity. Keywords:

Keywords: clarity; Hordeum vulgare; malting quality; variety

Published: June 30, 2009  Show citation