Pitching and Filling Procedures of Cylindro-Conical Fermentation Tanks and its influence on the Anti-Oxidant Activity of Beer

By Clemens Forster and W. Back Technical University of Munich, 1999 EBC Poster Freising-Weihenstephan,

Abstract
ABITRACT The protection of reducing substances derived from wort as well as the development of the antioxidant activity during fermentation are important factors for the flavor stability of beer. The antioxidant activity of beer is investigated by means of electron spin resonance spectroscopy in dependence on filling intervals and timing of aeration in cylindro-conical fermentation tanks. The development of the antioxidant activity shows an exponential correlation with the con- centration of sulfur dioxide formed during fermentation. Removal of cold break by flotation or cold wort filtration results in considerable reduction of the antioxidant activity. In case of multi-filling of cylin- dro-conical fermentation tanks, the timing, when aerated wort is added to the already fermenting wart, leads to significant differences in the antioxidant activity of beer.
Keywords: Cylindro-conical fermenters, Multi-filling tanks, Topping-up, Antioxidant Activity of cyl indro-conical  

Sintesis
La protection de las substancias reductoras derivadas del mosto asi coma el desarrollo de la actividad antioxidante durante la fer- mentacion son factores importantes para la estabilidad del sabor de la cerveza. La actividad antioxidante de la cerveza se investiga par medio de la espectroscopia de electrones resonantes en dependencia con los intervalos de llenado y el tiempo de aeration en los tanques cilindro c6nico de fermentation. El desarrollo de la actividad antioxidante muestra una correlation exponential con la concentration del dioxide de azufre formado durante la fermentacibn. La elimination del periodo de enfriamiento mediante la flotation o la filtration del mosto frio resulta en una considerable reduction de la actividad antioxidante. En el case de tanques de fermentation cilindro conicos de llenado multiple, el tiempo exacto cuando el mosto aireado se afiade al mosto ya en ferrnentacion, conduce a diferencias significa- tivas en la actividad antioxidante de la cerveza.