Dynamic Modelling and Simulation of Cold Contact Fermentation (CCF)

The increased commercial presence and comparative health benefits of alcohol-free beer (AFB) provide a substantial impetus for research, particularly in the field of dynamic simulation whereby the development of accurate models can help reduce costs of experimentation. Cold Contact Fermentation (CCF) is an existing method of industrial-scale AFB production that utilises reduced fermentor temperatures and altered contact times compared to Warm Fermentation (WF), though requiring continual attention given the production of non-optimal organoleptic compositions, which drastically affect taste. In order to better understand the differences between Warm Fermentation (WF) and CCF, a DAE system is constructed based on previous WF studies whose responses are compared vis-à-vis to simulations of the same model under industrial CCF conditions. Given the significant discrepancies between dynamic results, industrial data can be for the parametrisation of a new CCF model, in order to accurately portray plant operation. Further to these simulations, the sensitivity of final species concentrations to parameter variation and the effect of hypothetical temperature profiles are studied with the aim of evaluating model system flexibility and opportunities for improvement based on changes to fermentor temperature profiles. Overall, disparate relative ethyl acetate sensitivity and clustering of hypothetical CCF responses reflect existing challenges with flavour composition but highlight opportunities for remarkable process improvements.