Commercial Malt/Floor Malt/Home-Brewed Malt
It is manufactured from GM cultivars with specific characteristics. It is first soaked in water and then laid out in layers of 10 to 30cm thick on a cement floor and kept wet to allow it to germinate in the sun. The temperature of this malt bed can be controlled to a certain extent by adding water or making it thicker or thinner. As soon as germination has taken place satisfactorily, the wetting process is ceased and the malt is processed to a thin layer of about 5cm. The malt is then continuously mixed while being dried by the sun. Alternatively this malt can be dried mechanically as in the case of the manufacture of industrial malt. In order to obtain maximum shelf-life, drying takes place to a specific moisture level, after which the malt is milled and packed.
It is packed in containers from 500g to 80kg, and purchased commercially and brewed at home. Equal quantities of maize meal and floor malt are added to water and these are the only ingredients, with the exception of dry brewer’s yeast. The process then basically entails the acidification, cooking and fermentation of the malt.
Industrial Malt/Indoor Malt
GM cultivars are also used for industrial malting. The inherent quality requirements are much higher than those in respect of commercial malt. After the sorghum has been soaked in water, it is allowed to germinate. The whole process takes place indoors. Germination takes place in a controlled container system where ventilation is controlled to supply the correct amount of oxygen, to remove carbon dioxide and to regulate the temperature. This system lends itself to a deeper malt bed than in the case of the floor malting process, i.e. about 0,75 to 1,5m. Here the wetting of the grain takes place at intervals, while the grain is mixed by spiral screws positioned vertically in the container. Drying takes place in the germination container or in a separate drying oven.
Furthermore, a Sorghum Malting Technology Workshop has been established to enable those involved in the industry in South Africa to be trained for the manufacture of malt in a professional manner by attending a university accredited certificate course.