The characteristics of “koshu” (old sake) explained [Words related to sake].(kosyu)
Sake that has been aged for a long period of time. Sake made in the current year is called shinshu, while sake made before the previous year is called koshu. There are no clear rules for labeling old sake. As sake is aged, the content of sotolon increases, which gives koshu its unique characteristics, such as its brownish color and mellow aroma. Among sake, those classified as koshu are often the most expensive.






