Coloration degree (Chakushokudo)

Coloration degree (chakushokudo) is an index that measures how deep the color of sake is. It is obtained by shining light with a wavelength of 430 nm through the sake and measuring how much of that light is absorbed. Distilled water is used as the reference, and the standard is the absorbance at a sake layer thickness of 10 mm. The higher the absorbance value, the deeper the color of the sake. The coloration degree of commercially available sake is generally said to range from about 0.010 to 0.035. Measuring coloration degree is one of the important elements in quality control and in understanding the characteristics of a sake.