Chibuku

Chibuku is a commercial sorghum beer based on the traditional Umqombothi homemade African beers; the main grains used are malted sorghum and maize but may also contain millet. "Chibuku" comes from Max Heinrich's habit of recording all consumers' comments and process changes in a book. Chibuku is an adaptation of the local Zambia language word for "book" - "Chi" is the prefix meaning "big", "buk" = "book", and the terminal "u" is because most African nouns tend to end in a euphonic vowel. The shake-shake comes from the ritual of shaking up the beer before taking the first sip. The beer contains starch, germ, and yeast (all typically removed in lagers and ales), and since the solids settle to the bottom of the carton, it needs to be shaken before sipping. The alcohol content in a fresh Chibuku is relatively low, starting at about 0.5% ABV on day one. Still, as fermentation continues in the carton, the longer it is kept before drinking, the stronger it gets. It may achieve 4% ABV before the shelf-life expires after between 4 and 6 days after packaging.

Source: Wikipedia