There are many reasons I like sake. The otherworldly taste is certainly one of them. The dinky cups it's served in that makes me feel like I'm a character in Land of the Giants is another. Yet it's the legend of Yamata-no-Orochi, the eight-headed serpent killed by Susanoo, the Shinto god of storms, that really polishes my rice. In a Mortal Kombat-style death, the god born from snot – seriously – gets each snake head so pissed on sake he can chop the beastie up into little bits. What's not to love? Sake is the drink of dragon slayers.

It's also the drink of London in 2016. In the last 12 months a plethora of Japanese restaurants have hit the city, including the Kobe-centric Engawa in Ham Yard, Jidori on Kingsland Road and Tokimeite in Mayfair. When it comes to their drinks menu they all have one thing in common: they put sake centre stage. But what exactly is sake?

Sake is a fermented alcoholic drink made from rice. We all knew that, right? So what is it exactly? For starters, it's made up of four pure ingredients: rice, water, yeast and something called koji. Koji is an indigenous fungus or mould that is also used to produce soy sauce, miso, mirin, rice vinegar and shochu (another type of Japanese spirit), and it plays an important role in the conversion of the rice starch into fermentable sugars. The koji enzyme is also good for you: it helps reconstruct skin cells and also has a moisturising effect. Another reason to shoot the sake.

Sake sommelier Natsuki Kikuya, founder of London's 'invisible' Museum of Sake, says that many people in the UK think sake is a distilled spirit but, as you can see from the above, it's fermented. This confusion is added to by the flavour profile, which tends to mimic wine, whereas the production is actually very similar to beer.

"If the dominant quality of wine comes from the grape [or terroir], the quality of sake comes from human hands," Kikuya says. "Though sake is still a gift of nature and we have good and bad years for rice quality, this is still adjustable by the craftsmanship of sake brewers." When understanding the quality of sake the effects of brewers' techniques, precision and manipulation throughout the whole production matters the most to the final palate, she says.

The most impactful of these 'brewers' techniques' is rice polishing or milling, upon which the flavour and mouthfeel of sake depend. The rice is polished to remove impurities revealing the inner 'starchy core' and, in general, more polishing equals more purity of sake flavour. For instance, sake categorised as ginjo or junmai daiginjo is made from rice that has been highly polished; expressing "elegant, fragrant and fruity characteristics perfect for light dishes," Kikuya explains. On the other hand, junmai sake is made from rice that hasn't been polished as much, so the style is bolder, rustic, earthy; "a great umami-enhancer" when paired with like-minded dishes.

Sake rice is polished to remove impurities; more polishing equals greater flavour

Then there is sake that is bolstered with added distilled alcohol such as honjozu, a versatile, clean, crisp and dry sake that works well with a range of food, and futsu-shu, which translates as 'regular sake' (the equivalent of a house wine) and makes up 70% of the product on the market.

Discounting futsu-shu, which isn't considered premium sake, there are four special designation sakes. Got it? OK. Notebooks at the ready, because now we're really going to throw a chopstick in the works. There's also namazake – unpasteurised or raw sake with a limited season often drunk to welcome spring "while enjoying the cherry-blossom bloom." Romantic perhaps but try it and you'll catch Kikuya's drift. When you first taste namazake the extreme freshness and mouth-tingling liveliness is alarming. If springtime could be bottled, you get the feeling it would taste like this.

And that's not all. There are even more types: sparkling, cloudy, aged, kijoshu (a port-style sake) and taruzake (cedar cask-matured sake). And distinctive regional styles too, such as the light and crisp style of the Niigata prefecture or the sweet and acidic variety of the Saga prefecture. Yes. You may have gathered, mapping sake is nigh-on impossible, even if on a mini odyssey around the city I was able to pick up some rice-sized nuggets of zen-like wisdom.

At Nobu London, for instance, I learned how the eponymous, seminal chef drinks sake out of a wine glass (not a fan of Land of the Giants then, Nobu-san?), something the restaurant tries to emulate on its sake tasting events. According to general manager Stephan Guicheteau, it's the best way to get all those beautiful aromas up the schnoz.

Down the road at Shoryu, which boasts the largest sake list in London, the Hamlet-style 'to warm or not to warm?' question – whether Western establishments sell inferior sake warmed up in order to soften the harshness of off-flavours – was well and truly put to sleep by official Shoryu mixologist and Japanese bar consultant Maria Vittoria Vecchione. She revealed that warming some sake can blunt flavours but generally it doesn't really matter whether it's served hot or cold, it's more a matter for the thermostat than the taste buds. She's right. We should celebrate sake's versatility (while maintaining a gentle warm temperature of 40-45˚C).

You know you're drinking a good sake if it's balanced, structured and has smooth or velvety textures

Serpents and starch are all very well, but how do you tell a good sake from a bad one? Tasting sake is "pretty much the same as wine" says Kikuya, telling me how professional sake evaluators use special cups called kikijoko and detect negative characteristics rather than positive ones using both 'orthonasal' and 'retronasal' aromas (before during and after tasting).

Read all about it

Thirsty for more? Get yourself a copy of Sake: The History, Stories and Craft of Japan's Artisanal Breweries (£75), by Hayato Hishinuma and Elliot Faber, with photography by Jason M. Lang. Essentially a bible of all things sake, you'll be scrutinising rice-polishing techniques in no time... 

For those of us suffering from spring hay fever however, or if you're just too idle to sniff your way to sake wisdom like me, Kikuya says, in essence, "good sake holds balance and structure and has smooth or velvety textures, but each category has its own styles and no categories are better than others."

And this is what I love so much about sake: there isn't a hierarchy; pretty much all of it tastes good. No wonder Yamata the evil snake died getting battered guzzling down a vat of it; I'd have done the same. ■

museumofsake.co.uk