Influence of Fruits and Fermentation Time on Ethanol and Congener Production in Ombike Spirit in Namibia

Abstract

Africa has a diversity of wild fruit trees, whose fruits are used to make traditional distilled drinks. Their beverage potential for specialty brandies has not yet been tapped. One such beverage is Ombike, which is produced traditionally in Namibia from various indigenous wild fruits from trees such as Ziziphus mucronata, Grewia spp. (e.g., G. flavescens, G. bicolor), Berchemia discolor, Diospyris mespiliformis, and Hyphaene petersiana. The methods of processing, the quantities of ingredients, the conditions such as temperature and duration of processing are often variable and not well documented. There are currently very few to none consistent and standardized products of known quality of Ombike that can compete in the formal marketplace. The processing method for these drinks is broadly the same as that of many distilled spirits imported into the country. However, currently the technology used for processing in Namibia is traditional and therefore not optimized. This study investigated the effect of duration of fermentation and distillation fractions on the yield of the beverage’s alcohol and congener content. The alcohol content of Ombike sold at informal markets in Namibia was also measured. The alcohol content of a number of household-made samples of Ombike was generally lower (6–30%) than what would be expected in distilled spirits (43%). Controlled distillation can yield Ombike with an alcohol content of over 90%. With improved optimization and standardization of the process for producing it, Ombike made using dry fruits of indigenous Namibia wild trees could become a commercial specialty fruit brandy.