Three reasons for this belief are the red hue under the T.T.C. coloring method, that it did not increase on a beta-alanyn medium, and the pattern of electrophoresis. Consideration has been given, however, that it might be a mutation of the Kyokai Yeast No.7 because its characteristics are different, such as strong fermentation power and saccharifying of maltose, weak power of saccharifying of alpha-methyl gulcosid and high productivity of capronic acid ethyl. The results of studying brewing using this yeast have shown that the following operation is suitable. It is important to use rice having a low albumin content and low ratio of non-usable rice, by measuring the ratio of usable rice during the polishing process.
Preliminary testing is necessary before the rice is soaked in water.
After the rice is steamed, any additional water should be removed as soon as possible. When the rice steaming is completed, any steam remaining on the surface of the rice should be removed by dry steam. The rice should then be kept in ways that no more water evaporates. Dried koji spores are scattered over the surface of the rice. The most careful attention should be paid to scattering the dried koji spores, because the way of scattering decides the final quality of the koji rice.