Process improvement of opaque beer (chibuku) based on multivariate cumulative sum control chart

The brewing process of opaque beer suffers of lack of sophisticated measurement and good hygienic practices. Breweries of opaque beer experience variation in viscosity and beer quality. This variation is due to inconsistency in the manufacturing process and inputs/ingredients used in the brewing process. In this paper, the opaque beer (chibuku) was monitored via a statistical approach, multivariate cumulative sum (MCUSUM) charting. Monitoring was focused on different processes: gelatinization, souring, mashing, pitching, fermentation and packaging. These involve highly correlated variables including temperature, pH, time, viscosity and alcohol content. The variables were monitored simultaneously by using MCUSUM control charts. The results show that the quality of opaque beer (chibuku) is compromised by lack of uniformity in parameter measurement during production. More thorough inspection during chibuku brewing is required to ensure the consistency of measurable quality variables and to improve taste, shelf life and organoleptic characteristics of the beer. Copyright © 2017 The Institute of Brewing & Distilling