Malting and Brewing Properties of Selected Cereals Cultivated in Ghana
To promote the industrial use of local cereals in Ghana, studies were carried out on the suitability of malts from rice (WITA 1), sorghum (Kapala) and local late millet for the production of beer. The values obtained for mean diastatic power at the end of the malting period were rice (129.1oWK), millet (102.1oWK) and sorghum (84.0oWK). The saccharification time for each of the flour samples was less than 15 min using barley malt of diastatic power 340oWK. Significant differences (p<0.05) were observed in the wort pH, modification, attenuation limit and free amino nitrogen levels when these malts were compared with barley malt. Only sorghum malt had extract content which was significantly different (p<0.05) from that of barley malt. Saccharification time was less than 15 min for the non-barley malts when they were mashed using the three step optimized mashing scheme. Six types of non-carbonated beer (two from each cereal) were produced from the malt samples. The ratios of malted rice, sorghum and millet to barley malt used for the production of beer were 40:60 and 50:50 Results of sensory evaluation tests showed that the beer produced from a blend of 40:60 millet:barley was the most acceptable while that from 50:50 rice:barley was the least acceptable. Of the physical and chemical parameters analysed, beer pH appeared to influence acceptability more than all others with a correlation of 0.93. The findings of this study indicate that the varieties of cereals tested, particularly local late millet, are suitable for the production of distinctive beer types in Ghana.
Journal of the Ghana Science Association Vol. 9 (2) 2007: pp. 146-155