Optimization of low-cyanide TMS31/00110 (var. cassava) adjunct for the production of dark stout using two varieties of sorghum malts was carried out at varying concentrations. The malted sorghum varieties and the processed low cyanide cassava adjunct were separately milled into moderately coarse size using Institute of Brewing method. The Exogenous enzymes used include Alpha Amylase (Termamyl), Bioprotease, β-glucanase, Beta Amylase (Promalt) and Alpha Amylase (Bioferm). Worts of different concentrations were obtained with the aid of upward infusion mashing system. Three hundred milliliters (300ml) of tap water was used to dilute 50g of the mixed concentrated grist for the dark stout samples respectively. After complete saccharification from the mashing for about 2 1/6 hr, each mash was filtered to obtain clear sweet wort which was immediately subjected to various analyses. The clear worts obtained were boiled with hops for 45min, followed by cooling at15oC for pitching. The pitched worts were fermented for 6 days. Caramel (5mls) was added to improve the colour of the liquors. Colour intensities were determined for the stout samples using spectrophotometer according to European Brewing Convention method. Sensory evaluation tests were carried out on the stout samples using ten panelists, their judgment through questionnaires were statistically analyzed. The characterized worts showed that the original gravity ranged from 1046 to 1048o, for prospective dark stout using sorghum CSR-02 Variety. The original gravity of dark stout ranged from 1046 to 1048 o with sorghum ICSV-400. The wort pH ranged from 5.21 to 5.30, viscosities from 1.09 to 1.12CP for prospective stout samples from sorghum CSR-02 and ICSV-400 varieties. For reducing sugars, maltoses were 178.30 – 196.20mg/l; glucoses were 109.30 - 120.30. The cyanide content reduced from 4.50mg/l to between 0.03 and 0.00mg/l. The young stout beer obtained had the specific gravity ranging from 1015 to 1016o, and 1011 to 1013o. pH ranged from 4.68 to 4.78 and 4.28 to 4.32; % alcohol of 3.87 to 4.13% and 4.26 to 4.77%. The apparent fermentability was 3.15 to 3.53% at 22oC. The beer colour was 29 EBC. The Null Hypothesis was accepted since there was no significant difference among the samples produced at P≤0.05 level of significance.
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