Evaluating the Malting Quality of Hulless CDC Dawn, Acid-Dehusked Harrington, and Harrington Barley

Abstract

Hulless barley malt can result in significantly higher levels of extracts, lower freight costs, and reduced levels of polyphenols compared with conventional barley malt. The need for barley hull, which supplies no extract when brewing, has been reduced with the brewing industry's move toward new separation techniques, such as mash filters and centrifugation, versus the traditional lautering process where hulls are essential. Previous malting trials produced hulless malts with poor friability, possibly because of under modification or case hardening of the malt. To clarify the effect of hull absence on overall malt quality covered Harrington, hulless CDC Dawn, and acid-dehusked Harrington barley were malted under varying malting regimens. Hulless CDC Dawn malts produced significantly higher levels of malt extract than did covered Harrington malts, although, not as high as the 90% seen with acid-dehusked Harrington. CDC Dawn and covered Harrington malts had similar levels of enzymes and protein modification, but acid-dehusked Harrington still had higher levels of soluble protein that contributed to its higher levels of malt extract values. Freeze drying of green malt significantly improved friability values in hulless CDC Dawn and acid-dehusked Harrington, suggesting that regular kilning caused case hardening in the hulless and dehusked malts. It was concluded that high quality hulless malt could be produced provided appropriate malting conditions were used.