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Small scale mashes (BO g total grist) with grists containing high proportions of raw sorghum (50%-80% malt replacement) showed high values of extract recovery and produced worts of lower total nitrogen, free amino nitrogen, viscosity and colour but higher values of pH compared to worts produced from all malt mashes. Increasing the proportion of raw sorghum in the grist relative to malt resulted in a decline in extract recovery, wort total nitrogen, free amino nitrogen and an increase in wort pH.Addition of industrial enzyme preparations to mashes containing raw sorghum resulted in higher values of extract recovery (enzyme preparations containing a amylase and p glucanase), higher values of wort total nitrogen and free amino nitrogen (enzyme preparations containing a neutral proteinaae) and decreased wort viscosity (enzyme preparations containing p glucanase or cellulases) compared to worts produced from untreated mashes.Worts and beers were produced on a pilot brewery scale from 50% malt and 50% polished (whole) sorghum (single decoction mashing regime) and 20% malt and 80% raw sorghum supplemented with an industrial enzyme preparation (double mashing regime). Mashes comprising 50% malt and 50% polished sorghum showed comparable wort filtration behaviour (lautering) to that of control mashes (70% malt and 30% maize grists) whereas wort produced from 20% malt and 80% raw sorghum filtered slowly. Worts produced from grists containing sorghum were of high fermentability and showed lower levels of total nitrogen and free amino nitrogen compared to control worts. Analysis of worts produced from small scale mashes containing raw sorghum and a pilot brewery scale mash comprising 20% malt and 80% raw sorghum demonstrated that the levels of total nitrogen and free amino nitrogen were higher than expected from the reduction in the malt content of the mash, consistent with the release of nitrogenous components (polypeptides, peptides and amino acids) derived from sorghum into the wort.Beers produced from 50% malt and 50% polished sorghum and 20% malt and 80% raw sorghum were filtered without difficulty and were of sound flavour.Beers produced from 50% mart and 50% polished sorghum contained lower levels of isobutanol, 2-methylbutanol, dimethylsulphide and higher levels of n propanol and diacetyl compared to control beers.Key Word: Sorghum.Lager malt (moisture content 8%, total nitrogen content 1.6%DB) was supplied by Heineken Technische Beheer BV.Introduction , The moisture and total nitrogen content of the grist materials The economic policies of certain developing countries to utilise was determined according to the Recommended Methods of locally grown cereal crops as raw materials for the production Analysis of the Institute of Brewing6, of beer have led to a number of investigations of the use of sorghum as a brewing raw material in either matted or unIndustrial enzyme preparations malted form. Malted sorghum is employed in the production of Industrial enzyme preparations were supplied by Novo traditional beverages suc...

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The principles of amino acid analysis of proteins and polypeptides are reviewed. Analysis of the amlno acid composition of dialysed beer material prepared from a wide variety of commercial and pilot brewery beers showed that the principal amlno acids comprised glutamic acid/glutamine, proline, glycine and aspartlc add/asparagine.The results from the analysis of a series of pilot brewery beers brewed under standardised conditions showed that the composition of the grist may influence the amino acid composition of beer polypeptide fractions. Dialysed beer material prepared from beer brewed from grists containing terrified wheat, wheat flour and matted wheat contained greater proportions of glutamic add/glutamine compared to material prepared from all malt beers. Further fractionation and analysis of dialysed beer material prepared from pilot brewery beers suggested that fractions MW>60000 contained polypeptide material derived from yeast mannan-protein. In addition fractions MW>60000 prepared from beer brewed from grists containing torrified wheat, wheat flour or all malted wheat may contain high molecular weight polypeptide material derived from wheat proteins. The results from the analysis of fraction MW 40,000*60000 prepared from beers brewed from grists containing all malt, 80% malt and 20% torrified wheat and 50% malt and 50% malted wheat are consistent with the presence of polypeptide material derived from cereal albumins and globulins whereas fractions MW 40,000-60000 prepared from beers brewed from 80% mart and 20% wheat flour and 100% malted wheat may contain polypeptide material derived from wheat prolamins and glutellns. The amino add composition of fraction MW 20,000-40,000 from all pilot brewery beers investigated is consistent with the presence of polypeptide material derived from cereal prolamins and glutelins. The amino add composition of beer polypeptide fractions may be used to detect the use of wheat adjuncts in beer brewing.