"If you only remember one word about sake, remember ginjo". That's the tip from John Gauntner, one of the leading authorities on the Japanese rice wine. Basically, ginjo is to sake what premier cru is to wine. An American now living in Japan, John Gauntner further explains the relationship between ginjo and sake: "It's the same stuff, but made with better raw materials and by more labour-intensive, exacting methods that lead to a significantly better product."

Ginjo, with the even more delicate daiginjo at the apex of the pyramid, covers the top 7.5 per cent of sakes, while four in five sakes are commercial sakes known as futsu-shu. They are cheap because they are brewed with run-of-the-mill rice and cut with distilled alcohol for economic reasons. Between top and bottom, honjozo, brewed using a small amount of alcohol, and junmai (which means pure sake made from just rice and water) can often be the best value.

The better the sake, the more labour-intensive the process involved in its production. The strain of rice is important as well, with roughly 10 varieties of special sake rice accounting for more than 90 per cent of the 12,000-odd hectares of sake rice planted in Japan every year. The degree of rice milling is the key to the grade, and should be stated, along with the grade, on the label. Generally the more the rice is milled, the purer, softer and more delicate the sake's flavour.

The quality of water is also critical. Matsumoto, for instance, a traditional, ninth generation Kyoto family brewery, moved to its current location purely in order to be able to access Fushimi's pure water. As with wine though, the care that the producer brings to the process is massively important in determining the style. With more than 1,600 sake breweries in Japan, there are, not surprisingly, plenty of styles to choose from.

Sake hasn't caught on in this country as it has done in the US, but it's starting to happen. On 24 September, the second annual London sake fair takes place at the Japan External Trade Organisation, followed by a sake evening on 5 October at the British Museum (www.thebritish museum.ac.uk). And the launch of the Japanese fine dining restaurant Sake no Hana, by the restaurateur Alan Yau, is imminent. But a few barriers still need to be broken down.

In one sense, it's almost a relief that sake labels are mostly in Japanese, because you can admire their artistry without having to stress about what it all means. But if you want to know what grade you're buying or who and where it comes from, even the decoded script may not leave you any the wiser. Legal requirements such as alcohol content (which can vary from 13.5 to 18 per cent) are often buried in the middle of some indecipherable Japanese script while back label descriptions are mostly inadequate or non-existent.

Sake has been in decline in Japan for the past 20 years largely because the market has been flooded with inferior grades (and cheap Chinese sake). Understandably, people trying it for the first time have been put off. Not every supermarket in the UK sells sake, and those that do still list only the cheap stuff. The best of the everyday styles is Waitrose's smooth, fresh Sawanotsuru De Luxe Sake, £5.99, with Asda, Tesco and Booths' only marginally less satisfying Choya Sake, £5.74- £5.99, not far behind.

Upmarket stores like Selfridges, Harrods and Harvey Nichols stock high class ginjo and daiginjo from sake specialists Isake (www.isake.co.uk), but smooth as silk as Rashiku Junmai Ginjo and Rashiku Daiginjo are, they are not going to win too many friends at £18.20 and £22.99, respectively, in a small 30cl bottle. As yet, there's not a lot in this country between the cheap and cheerful and the heftily priced sake examples to encourage you at the moment, but I have a feeling that things are about to change.