Abstract
The relation between kinematic viscosity and years of storage of kokuto-shochu was investigated. A positive correlation between kinematic viscosity and years of storage was recognized in the measurement of kokuto-shochu which were stored 0.5-5 years in a stainless steel tank at ordinary temperatures. A similar tendency was recognized in the measurement of kinematic viscosity of awamori stored 1-15 years. When kinematic viscosities of kokuto-shochu or awamori stored 5-30 years were measured before and after distillation, no change in the kinematic viscosity by distillation was recognized. When kinematic viscosities of ethanol solution (25.05%v/v) kept 5.4 years in a glass bottle and immediately after dilution of ethanol (99.5%) with distilled water were measured, no difference in kinematic viscosity was recognized. From the results described above, we assume that the cause of the increase in kinematic viscosity of kokuto-shochu in proportion to years of storage in a stainless steel tank is the change in the composition of kokuto-shochu by chemical reaction and not a change in the ethanol-water cluster.
