1. Two fermentation methods have been compared for the production of Takju (Korean native Sake). One method (S1) uses $quot;Nuruk$quot; (Korean mold wheat) and the other method (S2) uses $quot;Nuruk$quot; and mold rice. The chemical analysis of source material, also, have been made in order the check the quantitative changes during the fermentation. The results are summarized below:
a. The rate of fermentation was slower for the S2 method than for the S1 method. However, the residual sugar in the S2 method was smaller and the amount of alcohol produced the same as with the S1 method. This was true in spite of the fact that the total initial sugar content for the S2 method was 10 percent below that of S1.
b. With both the S1 and S2 methods, 80 percent of the total alcohol production was obtained with in 3 to 4 days.
c. The pH value of the base material at the beginning of fermentation was markedly different between the two methods i.e.6.0 to 6.2 for S1 and 4.8 to 5.2 for S2. However, after one or two days the pH of both materials was about the same 4.0 to 4.2 and remained at this value unit the fermentation was complete.
2. Organic acids and Sugars in the source materials have been detected by the paper partition chromatography(p.p.c.) method and the followings are obtained,
a. Important Organic acids are Fumalic, Malic Succinic, Citric, Acetic aicds in polished rice and Fumalic, Succinic, Acetic, Citric, Malic and Oxalic acids $quot;Nuruk$quot;. The same kinds of acids as in the rice are found in mold rice, However, amount of Citrice acid is markedly increased in mold rice.
b. The important Sugar, Glucose, Fructose and Raffinose in polished rice, Gulcose, Fructo. se, Xylose and one which supposed to be Kojibiose in $quot;Nuruk$quot;. Glucose and those supposed to be Isomaltose, Kojibiose and Sakebiose and found in rice mold, however, no Sucrose, which was exist in polished rice, was found.
3. The important Organic acids found in fermenting mash using the p.p.c. method were Lactic, Succinic and Acetic. Citric acid identified early in the fermentation, S2 method, remained throughout. However, with the S1 method Cirtic acid was detected only during the late stage of fermentation. Sugars not found in the original materials were two which supposed to be Isomaltotriose and Pentose. Maltose found at the beginning of the fermentation disappeared within one day, Isomaltose was detected throughout the period of fermentation.
4. The Somogyi method which was employed to determine the quantitative changes of sugars in the original meterial and mach, showed that polished rice containes in order and in largest amounts Sucrose, Glucose, Raffinose and Fructose.
$quot;Nuruk$quot; contained almost equal quantities of Glucose and Fructose. However, the Glucose content of the mold rice exceeded that originally in the polished rice by 25 or 30 times. Only a small quantity of free sugars was found in the mash at the end of the fermentation.
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