Screening of Ghanaian sorghum varieties for lager style brewing

Abstract

Although sorghum is widely cultivated in Africa, its utilisation for the production of lager type beer by breweries is relatively limited. Sorghum is used unmalted as a brewing adjunct, in limited quantities, with barley and commercial exogenous enzymes for lager type beer production. The use of sorghum malt as the sole raw material in brewing lager type beers is generally limited because of its low diastatic power and high tannin content among other factors. The objective of this study is to identify sorghum varieties that could be malted and used as the sole (100%) brewing material for lager beer production. Twenty-six sorghum varieties cultivated in Ghana were screened for malting and brewing potential based on germinative energy, green malt hydration, gelatinisation temperature, extract yield, limit attenuation, free amino nitrogen and diastatic power. Five of the varieties; Kadaga, Nakpaji, Kazea Nanga, Global 2000 and Kyere, of the twenty-six evaluated were found to have desirable characteristics for producing quality malt for lager beer production without the need for supplementary enzymes. Pilot scale malting and brewing trials are recommended to validate these findings.