Potential of hull-less barley malt for use in malt and grain whisky production

Abstract

Hull-less (or husk-less) barley is possibly one of the most important developments in barley in recent years. This study looked at the potential of hull-less barley for use by the Scotch whisky industry. By modifying the malting conditions for hull-less barley, it was possible to provide good alcohol yield as well as significant improvements in processing characteristics. The biochemistry controlling the germination of hull-less barley was consistent with established knowledge about 'normal' hulled barley except that care is needed to ensure the consistency of feedstock, particularly since hull-less barley may be prone to embryo damage during harvesting in the field. Our results indicated that the new batches of hull-less barley studied, produced malt that gave much improved mash filtration rates in comparison with previous batches of material. These experiments demonstrated that by changing the malting conditions, to give a much shorter steeping cycle (8 h), it is possible to reduce water usage substantially in the malting industry, since only one 'wet' cycle was used, and also reduce germination times since optimum alcohol yield was achieved on day 4 germination rather than day 5 for conventional husked barley. This could save costs in terms of water, energy and time for the malting industry. The study also confirmed the potential of hull-less barley for providing significant benefits for Scotch whisky distillers, both in terms of higher alcohol yields, and increased throughput, by showing that it is possible to overcome some of the filtration issues that have been previously associated with hull-less barley. This study indicated that the new material was better suited than previous batches to both malt and grain distilling, both in terms of enzyme development and potential distillery performance, and further showed that viscosity problems associated with grain distillery co-products can be significantly reduced when using hull-less barley malt in the grain distillery. These would be substantial potential benefits for the Scotch whisky distilling industry. © 2009 The Institute of Brewing & Distilling.