These experiments were carried out to study influences of the kind of yeasts and of brewing condition on fermentation of Takjoo mash.
The results obtained were as follows:
1. Kind of yeasts and the number of yeasts in mash.
1) When the first stage mash was fermented at 20℃ for 1.5∼2.5 days and at 25℃ or 30℃ for 1∼2days, Takjoo yeast (strain D_m-1) and Sake yeast (strain No.7) showed little differences in the yeast population.
2) In the second stage mash that was fermented at high temperature, the number of yeasts was less as compared with the case of fermentation at low temperature, but the living yeasts number of Takjoo yeast (strain Dm-1) was more than those of Sake yeast (strain No.7).
2. Kind of yeasts and composition of ripened mash.
1) In the second stage mash that was fermented at high temperature(30 or 35℃), alcohol percentage of ripened mash using the selected Takjoo yeasts (strains: Dm-1, Y-1) was remarkably higher than the case of another yeasts (strains: No.7, No.6, No.396, No. 1).
2) Acidity of mash had a little differences between strain Dm-1 and strain No.7.
3) In the second stage mash that was fermented at high temperature (30 or 35℃), the amount of Formol-N using strain Dm-1 was remarkably less than strain No.7.
3. Brewing condition and alcohol percentage of mash.
1) The flt amount of wheat bran Kuk addition per material was 3 percentage and it was adequate to use the mixture of wheat flour Kuk 20 percentage and wheat bran Kuk 1-2 percentage.
2) Though brewing concentration of the first stage mash was duiluted by twice of general brewing concentration, the yeast reproduction was normal.
3) In addition of wheat flour 80∼140g per 180㎖ water, alcohol percentage of the mash increased almost propotionally according to the increase of the amount of wheat flour.
4) It was recognized that three stage brewing was superior in method to two stage brewing at present.
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