Tsuru-Bishio Aged Soy Sauce

This long-aged soy sauce is produced using a double-brewing method. Raw soy sauce matured for around two years is returned to the barrel, where additional ingredients are added and brewed again for a further two years. This technique uses twice the time and ingredients of standard soy sauce production and relies on natural fermentation to develop depth, aroma, and mellowness.

It is made at Yamaroku Shoyu on Shodoshima Island in Kagawa Prefecture, using clear local spring water. Fermentation is supported by yeast and lactic acid bacteria that inhabit the wooden barrels in which the moromi (fermenting mixture or ‘mash’) is aged. To preserve this environment, the brewery is also committed to maintaining the craft of wooden barrel making, which plays a vital role in the fermentation process.