Glycogen Released by the Yeast as a Cause of Unfilterable Haze in the Beer
MBAA TQ vol. 38, Number 2, 2001, Pages 95-98 |
VIEW ARTICLE
Philippe Malcorps, P. Haselaars, S. Dupire, and E. Van den Eynde. N.V. Interbrew, Leuven, Belgium. EBC Poster presented at the World Brewing Congress 2000, Orlando, Florida, USA. (reprinted with permission of the EBC and the authors)
Abstract
Some breweries were regularly faced with a persistent (20�C) haze in freshly filtered beer with some peak values up to 1.2 EBC. No clear relationship was found with bad filtering or brewing practices, changes in raw materials, or abnormal fermentation profiles. Palliative treatments like enzymes or fining agents were
unsuccessful. The haze was identified as glycogen spontaneously released by the yeast during the fermentation. The phenomenon was strongly dependent on the yeast strain, its physiological status, the gravity of the wort, and the fermentation temperature. Glycogen particles could be present in every beer but at different levels. Their impact on the
filterability and the clarity of the beer is discussed.
Keywords: Beer filtration, filterability, glucan, glycogen, haze, yeast strain
S�ntesis
Algunas cervecer�as se topaban regularmente con una neblina persistente (20�C) en la cerveza reci�n filtrada con algunos valores pico de hasta 1.2 EBC. No se encontr� una relaci�n clara con malas
pr�cticas de filtrado y de elaboraci�n de cerveza, con cambios de materia prima, o con perfiles de fermentaci�n anormales. Los tratamientos paliativos tales como enzimas o agentes afines no tuvieron �xito. La neblina fue identificada como gluc�geno que fue liberado
espont�neamente por la levadura durante la fermentaci�n. El fen�meno depende fuertemente de la cepa de la levadura, de su estado
fisiol�gico, de la gravedad del mosto y de la temperatura de
fermentaci�n. Las part�culas de gluc�geno pueden estar presentes en cualquier cerveza pero a diferentes niveles. Aqu� se discute el impacto en la habilidad de filtraci�n y la claridad de la cerveza.
