Kvasny Prum. 1992; 38(2): 33-41 | DOI: 10.18832/kp1992007

Fermentation and ripening. State of our present knowledge.Peer-reviewed article

L. NARZISS

The main factors of a principal fermentation and after fermentation are as follows: Wort composition (free amino nitrogen in percent of the whole nitrogen, zinc content), aeration intensity, homogenous distribution of yeasts, the yeast characteristics (strain, treatment), the cell number and the growth phase. The main factors of a ripening are as follows: the initial value of vicinal diketones, the number of yeast cells and temperature. The procedure of the two-day ripening at a temperature of 20°C after the cold principal fermentation begins to be preferred. Using the warm pressure fermentation, the same conditions and factors have to be maintained if the principal fermentation and after-fermentation would achieve the sevenday rythm which is suitable from the standpoint of organoleptic properties. With the shortened procedures the cold storage has to last about one week at a temperature below zero. The specialists of yeast physiology could be surprised with the finding that the yeasts of a bottom fermentation are able to keep their properties some generations only due to varying pressure conditions during a fermentation in large vessels. From this follows that there is necessary to prepare yeasts for the inoculation of a principal fermentation almost continuously. This type of a yeast propagation solves the problem of the yeast inoculation. Nevertheless, the problem how to minimalize the rest beer from waste yeast still remains. The solution of this problem comprises both the development of further equipments permitting a yeast separation from beer and the finding of procedures for an application of this beer. The time-shedule of critical points for an obtaining and application of beer from yeasts comprises the necessity to take into account the biological, qualitative event. organoleptic standpoints.
(In Czech, English summary only)

Keywords: beer, mashed wort, fermentation, CKT

Published: February 1, 1992