An expert system applied to the physiological analysis of early stage of beer fermentation

Abstract

A fuzzy expert system was applied to the knowledge analysis of yeast physiology in the early stage of beer fermentation, when the wort was aerated. We used ergosterol and glycogen concentration in the wort as a suitable marker of physiological state of the cell population. The amount of both compounds influences the rate of fermentation, cell growth and the final taste of beer. The concentrations of ergosterol and glycogen including the number of cells can not be measured immediately during the relatively short aeration period, and incomplete experimental data are therefore found in laboratory logbooks. We therefore suggested that the fuzzy relation between the directly measurable dissolved oxygen concentration and the rate of ergosterol or glycogen formation should be identified and a fuzzy expert system should be used to analyze the behavior of the yeast.

Estimation of the ester formation during beer fermentation using neural networks

“…Many proposals for the modelling of beer fermentation speed exist in the literature, perhaps due to the strong link to the models of alcoholic fermentation (Marin, 1999) and biotechnical processes (Linko, Zhu, & Linko, 1995;Te Braake, 1997). Kinetic models have been presented by Johnson et al (1998) and Linko et al (1995) or fuzzy modelling (Cummins, Plant, Kelleher, & O'Connor, 1998;Kashihara, Mawatari, Inque, Prior, & Cooney, 1993;Vassilleva, Huong, & Votruba, 1994). Such models are typically developed and tuned by hand, which was a considerable burden.…”

Ai-Based Software Tools for Beer Brewing Monitoring and Control

“…Industrial yeasts strains are microbial populations with certain morphological and physiological content and features of cells. With the methods of artificial intelligence (AI), implemented on experimental data, software analyzers are synthesized for defining: concentration of various kinds of yeast cells (living, death, weak, budding); budding energy and fermentation activity of brewing yeasts (16).…”

“…Kinetic models have been presented by Gopal et al and Johnson et al (6,7), fuzzy modeling by Vassileva et al and Cummins et al (5,16), and a rule-based system by Kashihara et al (8). Such models are typically developed and tuned by hand, which is a considerable burden.…”