From being an unknown quantity less than a decade ago, Japanese single malt whisky has rapidly become the hottest property in the whisky market. The days when people - who had never tried any - sneered that it was simply a pale imitation of Scottish whisky have long gone. The reasons for this change are many.

Japan has been making whisky since the early 20th century, but the domestic demand for it was so large, that export was never considered as a necessity (unlike Scottish whisky which has always been export-oriented). It was only with the Asian financial crisis in 1996 and the subsequent collapse in domestic sales that Japanese distillers began to consider that overseas markets might be a way of dealing with their sudden stock surplus.

The greater availability of the whiskies internationally revealed a style which, while taking its lead from Scottish whisky, has developed its own aesthetic and its own unique flavours. These whiskies are a revelation.

Japan's love affair with whisky started almost as soon as the port of Yokohama was opened to foreign trade 151 years ago. With that came Scottish whisky. By the beginning of the 20th century Japanese wine and spirit merchants were considering the possibility of making their own native version. Among them was Shinjiro Torii (whose form became found Suntory) who in 1923 built a distillery a few miles outside Kyoto in the small town of Yamazaki. Luckily he found the one person in Japan to have had first-hand experience of whisky making in Scotland, a young chemist called Masataka Taketsuru. (who went on to found Nikka).

Like Scottish whisky, Japanese whisky was founded on blends rather than single malt. To give the blenders a rich palette of flavours to work from, Yamazaki - and each subsequent distillery - was set up to produce many different style of whisky. Even today, Suntory's Yamazaki, its sister distillery Hakushu; and Nikka's duo - Yoichi and Miyagikyo - follow this remit making everything from heavily peated to unpeated and aging the spirit in a wide range of wood types, including the incense-heavy mizunara, or Japanese oak.

Although the Japanese distillers follow the Scottish template (and indeed get their malted barley from Scotland) there is a distinct difference to the final product. There is a purity of aroma, a transparency if you like, to Japanese whisky which you don't find in Scottish whisky. Intense, precise and ordered they rarely have the cereal note which lies behind most single malt Scottish whiskies.

The approach to the flavour of single malt is different. In Scotland, single malt means a single distillery making one flavour of whisky. This means that the distiller in Scotland has to use age and different woods to create a range of different expressions of this single character. Not so at Yamazaki or Hakushu.

Because there are so any different flavours to draw from, each age statement contains a different mix of components. That is one reason why the zesty, fresh Yamazaki 10 year old is different to the succulently fruity 12 year old and it is different again to the lightly smoky, sherried 18 year old. The same applies to Hakushu which starts life as a cool, minty, grassy 10 years old, but by 25 years shows elegant antique shop aromas along with smoke.

In the second of his monthly installments, Charles Maclean gives his thoughts on the Malt of the Month : Hakushu 12 year old and its Distillery. Japanese Single malts have been doing exceptionally well in blind tastings recently, and Hakashu is no exception.

Soft and fruity on the nose, with tinned peaches, lychees and mandarins. Behind this a cosmetic aroma of cold cream and Lux soap flakes. A hint of smoke. Water freshens it: fresh laundry, green apples, wild mint. A soft texture, with apples and a short, fresh finish.