Like Gizmo in Gremlins, sake does not tolerate “bright light” that well. Not only does the photophobic beverage discolor easily, sunshine, for example, often brings a modicum of heat with it, which begins to break the wine down. Sakes should be protected from light either by being stored in a cool, dry cabinet or sufficiently wrapped in a bottle bag. In either situation, it should be stored at a temperature below 68 degrees Fahrenheit. If treated in this manner, your sake might hibernate for a half a year or more, without significant alteration.
It’s cool to store your sake in the refrigerator (and no that’s not a play on words). Though you should rightly feel like a chump for keeping your red wine in the vegetable bin, your rice wine will love it – not least of which because the premium sakes, such as nama chozoushu and ginjoushu are often only pasteurized a single time versus the customary two times for lesser varieties. Namazake, however, isn’t pasteurized at all and like its premium brethren, needs to be stored at under 40 degrees Fahrenheit to preserve its nuances (and be safe to drink!). More to the point, these sakes are intended to be enjoyed mere weeks after purchase, if not days.
Likewise, most sakes are topped with screw-caps, a closure that produces an air-tight seal when properly closed. Since oxidation is one of sakes mortal enemies, consider “gassing” your sake with argon gas, an inert compound conveniently available in aerosol spray cans at most fine wine shops. A quick spritz and a deft recapping and you can revisit the same bottle several times without an appreciable change in quality. Banzai!