Determination of obscuration. Part III. Establishment of the obscuration factor in alcoholic strength determination

Abstract

The empirical value of the obscuration factor in determinations of alcoholic strength has been established as being 0.3. When applied to a series of 19 samples, the mean deviation of the calculated strength, with obscuration considered, from the true alcohol strengths determined after distillation is 0.02%V/V with a standard error of the mean of 0.05%V/V. It is recommended that the dry extract obscuration procedure be used in preference to the distillation procedure when the dry extract concentration does not exceed 10 g l^–1.