Iwase Sake Brewery
- Matsu
- Jan 24
- 1 min read
Updated: Jan 25
Iwase Sake Brewery stands out for its unique brewing methods, particularly its use of one of the hardest waters to brew Sake. This water has high levels of calcium and magnesium, making it rich in nutrients and promoting active fermentation. Also, they are famous for the Yamahai method of brewing sake and aged sake, they are one of the most classic and interesting of sake brews.
Iwanoi I240 series
To commemorate its 300th anniversary, Iwase Brewery has introduced the i240 series with a new label. The “i” stands for Iwanoi, and “240” represents the hardness of the water used. This series uses hard water, which is rich in minerals, significantly affecting the sake’s flavor, as 80% of sake is water. In Japan, most water is soft, while Europe and North America have more hard water found in its territories. For comparison, Evian has a hardness of 304, making it ultra-hard water, while South Alps Natural Water has a hardness of 30, making it soft water. The water used for Iwanoi’s sake has a hardness of 240, providing a high mineral content. This unique flavor, unlike any other sake, is offered using the same brewing method but with different sake rice varieties.
The water is very special; full of minerals!

The brewery is about an hour from Narita Airport, located in a green, peaceful residential area.

Their aged sake (Koshu) is also very popular. Iwanoi sake can be enjoyed fresh or aged, becoming milder over time and pairing well with any dish.


Komentarze