CHARACTERISTIC OF CONDUCTIVITY OF COMMERC IAL SAKE AND DURING BREWING

Conductivity of sake, commercial products and during brewing, was meas ured for the purpose of application of a conductivity meter to evaluat ing sake brewing process. (1) Temperature characteristics of conductiv ity of commercial sake was examined, and the temperature coefficient a lpha, of conductivity was derived as a function of temperature. The re gression equation computed was: alpha(t) = -1.77 ln (t) + 8.32 (R(2) = 0.96) where symbol designations were: t = temperature [degrees C] alp ha(t) = temperature coefficient at t degrees C [%/degrees C] And it wa s also able to apply to sake mash. (2) The effect of chemical componen ts on conductivity was examined with model solutions. Significant effe ct was observed of added organic acids in 15% ethanol solution, and ad ded amino acids in a sake sample. (3) The interactive effect of compon ents in sake mash on conductivity was examined. As the result of multi ple regression analysis, the most changes in conductivity was dependen t on the increase in amino acidity in sake mash. The single regression equation computed was: L(15) = 153.28 F + 209.62 (R(2) = 0.94) where symbol designations were: L(15):Conductivity at 15 degrees C [mu S/cm] F:amino acidity [ml] This relationship was applicable to several type s of sake mash. These results obtained here suggest that the applicati on of a conductivity meter to evaluation of sake brewing process is fe asible.