Partial Pressure and Concentration of Ethanol in Vapor Phase (Studies on Aged Spirits and Their Physicochemical Characteristics. Part III)

Abstract

In the previous works, the dielectric behavior, NMR spectrum and DSC thermogram of aged spirits were investigated. These studies indicated the formation of stable molecular clusters in which the migration of the ethanol molecule was restricted and there was a decrease in monomeric ethanol, which produced a stimulative taste. In the present study, changes in partial pressure and concentration of ethanol were investigated in the vapor phase of aged spirits. The partial pressure and the concentration decrease in proportion to the length of storage. The changes induced by aging were independent of minor chemical components, whose effects were investigated throughout the study. The aroma of the minor chemical compounds were easily perceived with decreasing concentrations of ethanol in the vapor of aged spirits and the stimulation of ethanol was reduced on the sense of smell with decreasing partial pressure of ethanol in their vapor. The findings explain the reduction in stimulative tastes and odor of aged spirits. © 1985, Japan Society for Bioscience, Biotechnology, and Agrochemistry. All rights reserved.