Mashing Studies with Unmalted Sorghum and Malted Barley
Declan L. Goode 1, 2, Catherine Halbert 1, 2 and Elke K. Arendt 1, 3
1Department of Food and Nutritional Sciences, National University of Ireland, University College Cork, Ireland.
2National Food Biotechnology Centre, National University of Ireland, University College Cork, Ireland.
3Corresponding author. Email: e.arendt@ucc.ie
J. Inst. Brew. 108(4), 465-473, 2002 | VIEW ARTICLE
ABSTRACT
The effects on wort quality when mashing with unmalted sorghum (0-100%) and malted barley (100-0%) in combination with industrial enzymes were evaluated. A mashing program with temperature stands at 50°C, 95°C and 60°C was used. Different combinations of commercial enzymes were evaluated. A heat stable α-amylase was found to be essential for efficient saccharification. The inclusion of a fungal α-amylase in mashes with a high sorghum content improved filtration rates to that of 100% malted barley mashes. Addition of a bacterial protease increased the amount of nitrogen solubilisation and peptide degradation. An increase of the relative proportion of sorghum in the grist resulted in decreases in wort filtration, colour, viscosity, attenuation limit, free amino nitrogen, high molecular weight nitrogen, and a corresponding increase in pH (p < 0.01). Overall the addition of malted barley in small proportions to unmalted sorghum mashes together with commercial enzymes was found to improve the potential for brewing a high quality lager beer from unmalted sorghum.
Key words:
Adjuncts, enzymes, heat stable α-amylase, malted barley, sorghum, unmalted sorghum.
Publication no. G-2002-1309-003 ©2002 The Institute & Guild of Brewing