Optimal conditions for propagation in bottom and top brewing yeast strains

The method of yeast propagation has an influence on yeast physiology, fermentation ability, flocculation rate, and taste stability of beer. In order to find optimal conditions for propagation, several parameters were investigated in combinations. The bottom brewing yeast grown at 10 degrees C indicated that a higher flocculation capacity during the 1(st) fermentation. However, the taste stability and the aroma profile were riot affected by parameters of propagation investigated. The beer quality was rather affected by storage duration. In addition, a correlation between tasting and chemiluminescence was found at the beer, which was produced using bottom brewing yeast. The propagation at 10-25 degrees C with addition of zinc ion indicated the best condition to improve fermentation ability, flocculation rate, and filterability for bottom brewing yeast, whereas the propagation at 30 degrees C with addition of zinc ion showed the best condition to increase fermentation ability for top brewing yeasts.