The Method of Measuring the concentration of alcohol in aqueous solutions by the phenomenon of cloudy precipitation in ternary solution

It is the common practioe that one, makes sweet-potato Shochu by fermenting the first mash consisting only of rice Koji for about 7 days and then by further fermentation of the second mash prepared by addition of the steamed, crushed sweet-potatoes to the first mash. The authors changed the process in several points: (1) Sweet-potatoes were used as cut, steamed pieces and added on the 9 th, and then on the 13 th day from the beginning (divided into two parts). (2) Rice Koji was decreased to about, half of the usual, and one third each was used at the beginning and at the times of addition of sweet-potatoes. (3) Rice and sweet-potatoes were steamed in an autoclave and vacuum was applied to cool them by evaporation. (4) A closed, large tank was used in place of an open jar. By these practices, the authors could suppress the sudden rising to too high temperature of the fermenting mash soon after the addition of sweet-potatoes and too rapid formation of alcohol leading to low yield. They raised the alcohol yield to 82% as the mean value for 6 tanks after acidification with HC1.