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.

Effects of Grain and Malt â-Glucan on Distilling Quality in a Population of Hull-less Barley

“…In addition, as this work was set up to compare the hull-less lines with Optic, a similar malting regime to that of Agu et al 3 was used. Agu et al 4 have subsequently shown that hull-less barley can malt successfully after a much shorter steeping period, so future work will also consider cell wall modification and wort filtration, in the context of malting regimes that require lower inputs of water and energy. Wort filtration rates were not quantified in this experiment as no obvious problems were observed with any of the hull-less samples, probably due to the high levels of cell wall modification that had generally occurred.…”

“…The advent of mash filters, which effectively squeeze out the wort, provide a solution for modern, large-scale breweries, but are not viable for malt distilling, which traditionally relies on large numbers of relatively small-scale production units. The extent to which filtration problems result from an absence of husk has, however, been questioned by recent research, within the distilling industry, as Agu et al 3,4 suggested that the extent of modification may be at least as important in ensuring rapid filtration.…”

Registration of ‘Buck’ Naked Barley

“…Buck is also suitable for malt, beer, and whiskey production under specialized conditions, given its potential to have high malt extract percentage. Naked barley absorbs water more rapidly that covered barley, which can reduce malting time, energy, and water needs (Agu et al, 2009). The hull accounts for approximately 11 to 13% of the grain weight but does not contribute to starch content; therefore, naked barleys have a much higher potential alcohol content than covered barleys (Agu et al, 2009).…”

“…Naked barley absorbs water more rapidly that covered barley, which can reduce malting time, energy, and water needs (Agu et al, 2009). The hull accounts for approximately 11 to 13% of the grain weight but does not contribute to starch content; therefore, naked barleys have a much higher potential alcohol content than covered barleys (Agu et al, 2009). Additionally, with advances in brewing technology and mash filters, many brewers no longer require the hull to serve as a filter.…”

Agronomic diversity of naked barley (Hordeum vulgare L.): a potential resource for breeding new food barley for Europe

“…At the time of writing there is only one naked barley cultivar on the UK National List: 'Penthouse', listed in 2005(FERA 2011a. However this cultivar was developed for malting, rather than food use, and further developments by Syngenta and the Crisp Malting Group are concentrating on improving the value of naked barley for whisky production (Agu et al 2009). …”