Fuzzy logic control for the isomerized hop pellets production

This paper presents an application of fuzzy logic control to isomerized hop pellet production. The hop is very important in the brewing industries because a hop of high quality provides a good aroma to the beer and gives consistency to the foam. The iso-merited pellets in this case study, are produced by warming stabilized pellets to approximately 50 degrees C and holding them for one-two weeks. The alpha acids are almost completely isomerized under these conditions. The fuzzy controller was shown to have a high degree of robustness producing good results such that the quality of the product is guaranteed. A comparison with other control approaches widely used in the industry is performed using a nonlinear computer model. (C) 1999 Elsevier Science Ltd. All rights reserved.