Water is involved in almost every stage of sake brewing, from washing the rice to dilution of the final product before bottling.
One of the most interesting aspects of the brewing practice is the fact that breweries use two sources of water, one hard and one soft. This is measured by the amount of magnesium and calcium or calcium carbonate. Japan tends to have slightly soft water compared to the rest of the world. So even what is called hard water in Japan, it is actually kind of soft when compared to the water in other countries. While soft water 'nansui' typically yield softer and sweeter sake, hard water 'kosui' with higher nutrient content, produced a drier style and quick finish sake.
Check out the Kameizumi Junmai Ginjo Genshu Koiku63 at our shop! Kameizumi means 'turtle spring' which is a tribute to the spring water used.