How long will unopened sake keep its character?
Answer From Expert Roger Bohmrich MW
This is a question I've addressed before as others are also concerned about holding bottles of sake, either opened or unopened. In brief, sake is not a beverage intended to be aged like fine wine even though a few aficionados have kept bottles just to see what would happen. Although most styles are pasteurized (except Nama-sake), almost all sake is fragile and in my experience will lose its freshness and understated aromatic complexity quickly if held for too long or stored in warm conditions. Taking this into account, some makers print the bottling/shipping date on the back label so that the trade and consumers have reliable information as to the sake's age after release. Nevertheless, while I may prefer the younger examples - enjoyed within 6 to 12 months of bottling - it's entirely possible someone else might like a bottle-matured version. But you should be aware that there really isn't a "road map" to indicate exactly what changes in flavor will occur, and over what period of time. Perhaps a better alternative is to look for Koshu sake which has been cellared by the brewer for varying periods before release. Someone who drinks standard types of sake would not recognize an old Koshu, which can be quite rich and full-bodied with overtones of honey, mushroom or nut.
