For preparation of all the beers, a paste was prepared from the cereal meal combined with water in the ratio 4:1. The mixture was allowed to boil for 10 min in a metal pot to gelatinise starch. Cold tap water (about a quarter of the amount used initially) was added to the
broth to reduce viscosity and lower the temperature to approximately 50 °C. Malt (half the quantity of meal used initially) was added to the broth and thoroughly mixed. The mixture was transferred to an earthenware pot and left to ferment spontaneously at ambient temperature (approximately 26–30 °C) until souring. Samples (about 5 ml) were tasted at various
intervals to determine the sourness until the desired sourness was attained. After the souring stage, the mixture was transferred to a metal pot and boiled for at least 1 h. The mixture was left to cool to room temperature after which malt was added. Sufficient sugar (approximately 130 g/l) was added to achieve a range of 16–18% dissolved solid contents for the high gravity fermentations and the mixture was put into an earthenware pot and left to undergo alcoholic
fermentation for about a day. Masusu was prepared as described elsewhere [6], using finger millet malt and sorghum malt for the beers brewed using finger millet malt and sorghum malt, respectively, then added to the mixture, which was then passed through a 3 mm-screen sieve. After sieving, the beer was left to ferment for about a day then the beer was ready to
drink. All the beers were prepared in duplicate.