Deep groundwater of the Kongo–Katsuragi mountain range
Very hard water (Hardness exceeding 200mg/L)
The importance of water in the process of making sake is evident when you consider the sheer volume of it that is required. For example, if you were to make sake using 100kg of rice, you would need to use about 150L of water. If this resulted in 220L of sake, it could be said that 70 percent of the product is the water.
All the brewing water we use, and in fact all the water used at our brewery, is drawn from our two wells on site. The water flows from the Kongo–Katsuragi mountain range and is drawn up from 100m below the ground. It is very low in iron and manganese making it optimal for brewing sake.
Conventionally, soft water is used for making sake. The hardness of the brewing water has a large influence on the characteristics of the resulting sake. Sake made with soft water is generally crisper while sake brewed with hard water has a thicker more voluminous quality to it. This difference is brought about by calcium and magnesium which are present at higher levels in hard water. The water drawn from our wells easily exceeds 200mg/L in hardness. This mineral-rich water forms the backbone of our sake and contributes a dignified quality to our sake. The high magnesium content helps boost the activity of the yeast but when this is combined with the minerals from the low-polished rice, the fermentative capacity of the yeast becomes explosive.
During the initial stages of the fermentation process, we take full advantage of this mineral-driven boost. As fermentation progresses, however, the advanced temperature controls on our proprietary tanks, enable us to drastically lower the temperature of the mash and thereby soften the pace of the fermentation. This allows for a long period of fermentation of over 30 days during which we carefully manage the balance between saccharification and fermentation.
This water, refined and honed in the lushly green Kongo–Katsuragi mountain range, is a key element in our fermentation process and an important factor in determining the texture of our sake. We hope you can enjoy its dynamic taste and texture.