The potential to utilise low nitrogen barley for production of distilling quality malt was studied. This presents an opportunity to reduce the environmental impact of nitrogen fertiliser applications. Malting barley (cv. Octavia) was grown without the application of inorganic nitrogen fertiliser, to produce grain with a relatively low nitrogen concentration (1.16 %, dry weight basis). Following micro-malting trials, dextrinizing units (58 DU) obtained from low nitrogen malt were much higher than a typical specification of 45 DU for malt with a conventional nitrogen concentration (<1.5 %). A higher soluble nitrogen ratio (SNR), or index of modification (IoM), of 49 indicated greater modification of the low nitrogen barley, resulting in higher extract released into the wort. Additionally, much lower levels of β-glucan were found in low nitrogen malt wort (64 mg/L compared with over 100 mg/L in wort of conventional nitrogen malt). Low nitrogen malt also produced higher predicted spirit yields following wort fermentation and wash distillation. These findings indicate that lower nitrogen concentration barley can be processed without negatively impacting malt quality for distilling applications. The implication of these findings to help realise more environmentally sustainable production of barley for malting and use in distilling is also discussed briefly.
|Number of pages||7|
|Journal||Journal of the American Society of Brewing Chemists|
|Early online date||21 Aug 2020|
|Publication status||E-pub ahead of print - 21 Aug 2020|