Session Chair:
Sandra Stelma (Process capacity, Agility and Futures Manager- Beer and Spirits, Diageo, IE)
Overview of biofuel fermentations – insights, parallels and contrasts with brewers’ production practices
By Zoltan Szigeti, Human Engineering
The biofuel industry is an emerging area of biotechnology, especially seen against the background of climate change. Although brewing has a much longer legacy in the field of fermentation, than the biofuel industry, the point of why this legacy should not exclude learnings from each other is a most relevant one. In this review presentation, a close look into the differences and similarities of a mainly performance oriented vs. quality-oriented processes will be provided to the audience. Of heightened interest to brewers will be a detailed comparison of fermentation kinetics in brewing vs. in biofuel fermentations, as a result of:
- Crushing and milling – particle size distribution and its yield impact;
- Mashing – fermentable to solid content process control and the potential for improving Cp and Cpk;
- Fermenting – pitching rates, enzymes, nutrition management and conversion efficiency;
- Expectations of product yield in general.
Development of a bacterial biocontrol process applicable in the barley-malt-beer industry
By Eusèbe Gnonlonfoun et al., Université de Lorraine
Pathogenic fungi represent a generic problem for cereals as they can produce a variety of mycotoxins that represent a significant concern for the malting and brewing industries, as they may affect the quality and safety of barley, malt, and beer. In order to guarantee a better hygienic and technological quality of the malt, despite the increasingly complex and variable conditions for barley production, this communication will describe the development of an innovative biocontrol process for malting facilities. It will be based on technological bacteria, isolated from infection-resistant barley cultures, that can reduce the development of spoilage fungi and the associated mycotoxin production. The experimental approach consists of: i) determining the growth kinetics of the bacterial and fungal strains by co-culturing in order to evaluate the impact of these bacteria on the fungal pathogens; ii) carrying out a micro-malting process in order to develop the aforementioned process, and iii) evaluating the technological and sanitary properties of the generated barley malts in order to validate the process developed.
The impact of long-term pitching yeast storage on viability and fermentation performance
By Carsten Zufall et al., Cervecería Polar
The purpose of this study was to evaluate which yeast storage conditions allow the pitching yeast to conserve maximum viability and fermentation performance. For that, a lager yeast cropped after a 3rd fermentation cycle was subjected to different pretreatment and storage conditions during a three-month period. Pretreatment included washing the yeast with sterile process water. Storage conditions were varied by different gassing regimes both with air or carbon dioxide. Alternatives for an activation protocol prior to fermentation were also evaluated at laboratory scale after storage. Yeast was tested weekly for viability and microbiological purity. Additionally, a laboratory scale fermentation was performed monthly to evaluate the performance of the yeast from the different trials.
Finally, the combination of the most promising pretreatment, storage conditions and re-activation technique was successfully tested on industrial scale. The availability of a large amount of pitching yeast complying with the required viability, fermentation performance and microbiological purity is a decisive advantage saving up to two weeks of run-up time after a brewery shutdown.
Archeochemistry reveals the first steps into modern industrial brewing
By Stefan Pieczonka et al., Helmholtz Institut, TUM
The molecular composition of an exceptionally well-preserved beer bottle from the German Empire era represents a unique source about the brewing culture at the end of the 19th century, when pioneer innovations laid the foundations for industrial brewing. Comprehensive analytics including metabolomics, microbiological, sensory and beer attribute analysis could certify the unprecedented good condition of the sample on a molecular level. It enabled us to decipher molecular fingerprints for technological aspects of historical beer brewing. Besides, we describe compositional changes of beer metabolites coming with long-term chemistry in such sealed complex organic mixtures (beer ageing). By the archeochemical approach, the historical production process of the beer could be traced and the ravages of time made visible.The holistic non-targeted analytical approach not only is restricted to unraveling molecular signatures and analytical marker substances for beer quality and alterations, but could highly contribute to guide modern and industrialized brewing processes such as malting (Maillard reaction), fermentation or stability during storage. (submitted as oral presentation)