Malting Performance of Normal Huskless and Acid-Dehusked Barley Samples

Abstract

Sulphuric acid dehusked barley had a higher germinative energy and lower microbial infection than normal huskless (naked) barley, suggesting that the pericarp layer harboured microbial infection which may have limited the germination rate. Dehusking the normal huskless barley using sulphuric acid resulted in lower microbial infection, and increased germinative energy. The normal huskless barley sample had a higher b-glucan content than the acid-dehusked barley and had slower b-glucan breakdown during malting. This resulted in the release of seven times more b-glucan during mashing, and the production of wort of higher viscosity. The normal huskless barley sample had a higher total nitrogen content than the acid-dehusked barley but both samples produced similar levels of amylolytic (a-and b-amylase) activity over the same malting period. No direct correlation was found between barley total nitrogen level and the amylolytic activity of the malt. When barley loses its husk at harvest, the embryo is exposed and may be damaged. This may result in uneven germination which can reduce malting performance and hence malt quality.

Performance of Husked, Acid Dehusked and Hull-less Barley and Malt in Relation to Alcohol Production

“…It was, however, considered that this material would most likely be applicable in malt distilleries using a wort filter, rather than a mash tun. Studies also showed that hull-less barley appeared to have higher levels of β-glucan than husked barley 5,13 . If a suitable enzyme-rich hull-less malt could be produced, this could potentially find an application in the grain distillery, and the intrinsic high alcohol yield from the malt would enhance distillery yield.…”

“…One of the most significant advances in the use of barley was the development of hull-less barley types which might be suitable for use in the production of Scotch whisky. Some studies carried out on hull-less barleys appear to suggest that they contain important brewing qualities, especially with regard to high extract recovery from the malt 5,13 . Also, previous work at the Scotch Whisky Research Institute (SWRI), looking at an early type of hull-less barley, has shown that the use of malt from this type of barley can provide substantially higher alcohol yields, compared with conventional barley malt.…”

“…Also, previous work at the Scotch Whisky Research Institute (SWRI), looking at an early type of hull-less barley, has shown that the use of malt from this type of barley can provide substantially higher alcohol yields, compared with conventional barley malt. Although hull-less barley will malt faster than conventional barley 5 , one of the problems identified was that the absence of a suitable filter bed, normally provided by the husk component of conventional barley, would lead to problems with drainage, particularly in relation to malt distillery applications 12 . It was, however, considered that this material would most likely be applicable in malt distilleries using a wort filter, rather than a mash tun.…”

“…Initial work was carried out on this batch of hull-less barley at SWRI (unpublished data) and elsewhere 5 looking at its malting characteristics. Since the quantity of hull-less barley provided by the plant breeder for this study was limited, it was necessary to prepare our own micro-maltings to provide sufficient sample to undertake our studies on this material.…”

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

“…Two obstacles have been identified, however, the first being the protective function of the husk 19 in avoiding damage to the embryo during grain handling, which could lead to poor or uneven germination during malting 5 . However, views on the severity of this problem differ and some studies show malts, from hull-less barleys, to have modified as well as the husked controls 13,20 .…”