Genroku no Daikoshu (元禄の大古酒)
Genroku no Daikoshu is sake which is believed to be prepared in the Genroku era and took off a seal in Mochizuki-machi, Kitasaku County, Nagano Prefecture in 1968.
It was brewed around 1689 and its Nihonshu moromi-zukuri was stored including solid contents without filtration. So, the aging period is 279 years.
When it was opened, the contents decreased by evaporation and the alcohol degree rose to 24%. It is much higher than that of normal sake. It is assumed that it was because the difference of molecular size between water and ethyl alcohol made the difference of penetrating power.
The color of sake turned black.
The container was a white porcelain pot and the cap was lacquered paulownia sealed by giving a final coat of lacquer. The pot is owned by Osawa Shuzo Shiryokan now.