Melon, banana, green apple. Strawberry, cotton candy. No, wait, dehydrated strawberry, and banana bread, not banana. These familiar modern day sake tasting notes are ones that aren’t likely to be seen in the journals of consumers much before 1981. The reason? Well, it’s simple - brewing technology and machinery, or lack of it.
There are eight grades of premium sake - tokutei meisho shu - and the top half of this division can be umbrella termed as ginjo, made with rice grains that have been milled down to 60% or less of their original size (and often a lot less).
Although sake in some form or other has been around not far off 2,000 years, and in a form pretty recognisable with today’s sakes for 1,000 or so years, ginjo sake is a phenomenon from as recent as the 1980s. Since then, in a period where the once mind-blowing inventions such as CDs, camcorders and MTV have been cast aside and replaced, the love for ginjo has remained strong.
So what was sake like pre-1981, in those hundreds of years before technology and sophisticated brewing kit landed and transformed the industry? Let’s take a step back in time on a trip into yesteryear when sake was the true national beverage of Japan and being churned out at its peak by far more than today’s 1,200 or so active breweries.
Enter stage right kimoto and yamahai, the only options available for a yeast starter before the main fermentation. At this time we find ourselves in an industry where rice milling was largely non-existent (and incredibly expensive and labour intensive when it was available), the yeasts in use are ‘wild’ and simply hanging around on brewery walls and ceilings and any other labour-saving processes or chemical simplifications just aren’t on the radar.
In short, it was all a bit rustic, rudimentary, artisan and unreliable. Had it not been for the skills shared by the highly esteemed Toji Guilds and ongoing obsessive professionalism of the brewing teams, it’s not hard to imagine an industry doomed to only limited success rates in sake production.
But what exactly are kimoto and yamahai? There’s books and courses written about this, so to keep it simple, I’ll focus on kimoto in this piece, and then move onto yamahai in another. OK, here we go, hold on to your hats.
In Sake 101 terms, before a brewer can start the main 20-35 day fermentation (the ‘moromi’), a smaller yeast starter ‘moto’ (or ‘shubo’, they’re interchangeable) is needed to kick things off which in itself takes 14 days to build up from the raw ingredients of steamed rice, koji (rice propagated with koji spores) and water.
These days there’s a fourth and fifth ingredient to today’s fast fermentation starter (‘sokujo-moto’): yeast itself and lactic acid. However back in the day, for kimoto the brewer relied on naturally occurring lactic acid bacteria falling into the open moto vat, along with the wild yeasts.
These bacteria form a high lactic acid presence in the waters killing off pretty much all the other nasties therein, namely the entire microbial population that can detrimentally affect the finished sake. In turn, sake yeasts from the brewery itself would take a tumble into the vat but are man enough to deal with living amidst the lactic acid and it’s suddenly game on.
So the goal of kimoto is to naturally harness the cleansing functionality of lactic acid so that the yeast population can safely explode and turn the sugar into alcohol. Yet there is one overriding factor that defines kimoto, which is in part largely responsible for the reason this older moto method takes more time, 28 days in total, than the modern faster process, and that’s ‘pole-ramming’.
You’ll probably have seen in most sake books, on YouTubes and Japan tourism websites the somewhat regimented brigade of brewery workers in the happi coats, oar-like poles in hand, rhythmically setting about pulverising the rice contents of wooden tubs. And that’s largely how it’s done, with the occasional motivational song thrown in for good measure.
Because to brew using kimoto method, the thinking at the time was that this pole-ramming, known as yama-oroshi, was required as a catalyst for lactic acid creation, and subsequently natural yeast propagation. This physical element was maintained for centuries up until 1909 or so, when sake productions was by vast majority kimoto made.
Nowadays, kimoto brewers do in fact elect to add some laboratory cultivated yeasts to ensure product consistency year on year but the pole-ramming remains for the creation of naturally occurring lactic acid bacteria.
There are some nuances too. The smart cookies in Akita Prefecture have simplified things a little further by harnessing technology. Their use of a large electric drill, seriously large, with a jagged metre-long drill bit, is used to purée the moto instead of the wooden poles. While it may seem like they’ve raided a Wes Craven film set, there is some great kimoto being made (and no brewery workers with aching muscles in sight).
It’s for all these reasons of hardship, risk and craftsmanship over the centuries that is exactly why you should try kimoto. It’s a taste of sake history, glugged by hardworking Japanese menfolk, living tough lives and doing proper strenuous jobs.
At Sake Central, we’re of course big on these natural lactic acid sakes. Over that 28-day moto period, the sake will, to some extent or another, have entertained a broad range of natural bacteria until their annihilation by lactic acid, but their presence is felt and you tend to get a richer, gamier, wilder flavour profile in the end sake.
Our out and out recommendation would be Kasumi Tsuru’s brilliant kimoto junmai from Hyogo Prefecture. ‘The Crane of Kasumi’ is located on the Sea of Japan and is almost unique in that it crafts its sakes using only the kimoto and yamahai brewing methods.
On the nose it has notes of a freshly baked Madeira sponge cake and it has a crisp taste and a gentle sourness, that characteristic kimoto tart astringency.
From there it goes into flavours bordering on vegetal, with an almost fermented rawness of something like daikon. This would be a brilliant accompaniment to fillet steak. The brewery itself recommends crab as another good pairing, and they should know - in 2025 the brewery will be 300 years old.
So pick up a bottle today, join the resurging popularity in kimoto, and celebrate Kasumi Tsuru’s 295th birthday with this amazing surf ‘n turf menu suggestion!
Will Jarvis is based in Hong Kong and the author behind Sake Matters, focusing on the Japanese beverage and surrounding culture. Will has previously worked for a variety of international food businesses around the world, is a trained chef and certified Sake scholar.