Continuous primary fermentation of beer : yeast immobilization kinetics and product quality

• Autor(a) principal: Brányik, Tomáš
• Data de Publicação: 2005
• Outros Autores: Vicente, A. A., Teixeira, J. A.
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)
• Texto Completo: http://hdl.handle.net/1822/4674
• topic: Beer; Continuous; Fermentation; Immobilization; Spent grains; Kinetic model; Cerveja; Contínuo; Fermentação; Imobilização; “Drêches”

A one stage continuous primary beer fermentation consisting of brewing yeast immobilized on spent grain particles in a gas lift reactor was studied. The goal of this work was to adjust the flavor of the continuously produced green beer to the desired character by sparging an adequate amount of air and by controlling the fermentation temperature in the immobilized yeast reactor as well as to predict the rate of the brewing yeast immobilization using a kinetic model adapted to the conditions of beer fermentation. The volumetric productivity of the continuous system was approximately 5 times higher than of the batch fermentation. The aroma profile of green beer from the continuous immobilized fermentation, run at zero air flow and temperatures 13 16°C, was fully comparable to that produced by industrial batch technology. Generally, the diacetyl concentration in green beer from the continuous fermentation was higher than in batch process, however, its re-assimilation was enhanced by high total biomass concentration in the system.