It’s no secret that the best Japanese whisky can be hard to find – even in Japan. Despite all the limited-edition bottles and the re-releases of old single malts, the good stuff is in chronically short supply. In fact, there’s even less Japanese-made whisky out there than you think.

With only about a dozen whisky distilleries in the entire country, Japanese whisky makers simply haven’t been able to keep up with the increasing demand over the past decade. Many distillers have taken to blending their product with whisky bought from overseas in order to make supplies last longer. Although Japan isn't the only country where distillers do this, drinkers looking for purely Japanese whisky find it hard to sort out what's what.

Unlike in Scotland, where adding booze from another country to the mix means you can’t call it Scotch anymore, Japanese whisky has never had a formal definition of production. That means there's nothing stopping an unscrupulous brand from blending Scotch with shochu, or simply importing whisky from overseas, bottling it here in the country and then slapping on a ‘Japanese whisky’ label.

That’s about to change, thanks to a new set of rules announced by the Japan Spirits & Liqueurs Makers Association (JSLMA) last week. After years of consultation, the group has released a set of criteria a spirit must satisfy in order to be called Japanese whisky. The full list of rules is published in English on the JSLMA website, but here are some key points, most of which revolve around provenance:

The spirit must be fermented, distilled and aged at a distillery in Japan

It must contain malted grain (eg barley, wheat, rye), but other non-malted cereal grains can also be included

Water used to make the spirit must be extracted in Japan

The spirit must be aged for at least three years

It must be bottled in Japan