6. Summary

The results of the survey and research on this project are summarized as follows.

  • Based on the survey period and sampling number, the main purpose of this study was to investigate the relationship between geology and prepared water in the Japanese Islands with a macroscopic stance. (Geological Zone: NE Japan / SW Japan (Inner zone / Outer zone))
  • According to the trilinear diagram of 283 water samples, it has been clarified that SE Japan concentrates on type V to type I (mixed to alkaline earth carbonate type), and the SW Japan inner zone concentrates on type I (alkaline earth carbonate type).
  • Water quality is the flowing groundwater type such as flowing through river terraces and coastal plains, and the source rock dependence type, that is, is affected by the elution of Ca2+ and HCO3 due to deep weathering of granite. 
  • Since the presence of granite characterizes the geology of the Japanese Islands, it is felt that the groundwater involved in it can also be said to be a Japanese-style terroir.

7. Afterwards

Unfortunately, some on-site surveys were not conducted due to the declaration of COVIT-19 infection emergency, including the planned survey area of SW Japan outer zone (accretionary prism area). However, I felt that the “Buratamori-style” sake brewery visit as this field survey was effective as a new sake brewery tourism style. By looking around the brewery and the water source, you can better understand the history and origins of water used by sake brewing.

Through this research, we hope that you will widely learn that the groundwater of the Japanese Islands, or the prepared water of sake, was created by the dynamic earth’s activities of plate movement for hundreds of millions of years.


We would like to express my gratitude to all the sake breweries nationwide who provided us with prepared water during your busy schedule.

This survey is based on the National Tax Agency Reiwa 2nd year Japanese liquor branding promotion project “Terroir Branding by Systematizing Water Quality Analysis of Sake Prepared Water corresponding to Geology”. I would like to express my gratitude to the authorities concerned here.