Advanced real-time control and optimisation of mixed fermentation of beers
Mixed fermentation (beer fermented with mixed yeast and bacteria species) used to be the standard practice in the UK, but demanding brewing science and requirements for more advanced control and modern equipment made single species fermentation the current norm. The fast growing craft brewing sector is now keen to re-discover the spontaneous mixed fermentation. However, the biggest challenge in mixed-culture fermentation is the control of the optimum balance among the microorganisms involved. This PhD project will focus on developing, improving and optimising advanced real-time control strategies in mixed fermentation. In this project, in order to achieve optimal and consistent production of mixed fermented beer, feedback control will be based on not only the traditional fermentation conditions (e.g. temperature, pH, O2, substrate feeding), but also novel measurement and estimation of expression rate and cellular growth rates. The project will involve laboratory scale beer fermentation trials, real-time control system simulation, design and implementation.