The Weathernews site asks one blossom-viewing question that you may not have thought of – what colour bottle is best to protect your sake from ultraviolet light?
Hanami ([cherry] blossom vewing) in Japan is all about the sake, right? But how well does its bottle protect it from the spring sunshine?
One thing to watch out for, especially if you plan to take your time sipping on a bottle under a cherry tree over the course of a Saturday or Sunday, is exposure to ultraviolet light. Along with high temperatures, this is one thing that can really harm sake.
Even a few hours of exposure, particularly to sunlight, will induce a change of colour – turning the sake brown and making it smell like scorched wood. The Japanese term for this is nikkoshuu (日光臭, the [unpleasant] smell of being exposed to sunlight). The sake‘s original aroma will be lost and its flavour will deteriorate.
So what can you do to keep your precious nihonshu safe while enjoying it on a sunny day? Check the colour of the bottle, which determines how much ultraviolet will be absorbed by the glass and therefore how much will reach the sake. Many modern bottles are clear glass, frosted, blue, green, brown or dark brown. Or, um, waxed cardboard cartons.
Interestingly, frosted glass turns out to be worst at absorbing ultraviolet rays, ranking even below clear glass. Next is blue, followed by green, brown and dark brown – although your best choice for avoiding this particular problem is the waxed cardboard carton. (The quality of sake you find in such cartons is a separate question…)
- Original article (Japanese, Weathernews, 23 March 2019) Click through and scroll down for an impressive photo of a clear glass bottle of sake exposed to ultraviolet light, next to one that was not. Graphic of least to most ultraviolet absorption from “Secrets of the Sake Sennin” by Food & Beverage Specialists Organization (FBO), parent organisation of the Sake Service Institute (SSI), who provided the ultraviolet exposure photo.