Rice Polishing: How Low Can You Go?


Three years ago, I walked into a bar and drank a sake that changed everything for me. Until then I’d understood that there was a direct correlation between how much a brewer polishes his rice and how good the resulting sake will be. Premium sake? That’s the stuff made from rice that’s had 50% polished away, or is it?

Sake had never spoken to me in my first 10 years of living in Japan, unbelievable, right! I’d it on numerous occasions but it never stood out as a serious alternative to wine or beer. Unable to read a sake menu, I had always been recommended easy drinking sake with very little character. Looking back, maybe I was just going to the wrong places not giving myself the chance to try new things. Musubi, from Terada Honke brewery located in Chiba, changed all of that! The sake, which resembles more of a sour beer, was nothing like I’d had before. Everyone into sake has that moment of revelation, and they can all remember what sake it was. Musubi was my moment. A sake made from 100% unpolished rice. Some would say that my moment was not warranted since Musubi is nothing like a sake. And I would partly agree with them. It really is nothing like a sake but that’s maybe why it got my attention. It showed me how far sake can go and how wide the favour profile can be. It also meant that there must be everything in between flavour wise but more importantly, to approach polishing ratios with caution.

So what is all this rice polishing about? Before rice is fermented, it goes through a process of polishing and the brewer has the option of what level of polishing to work with, shown on the bottle as a percentage known as the rice polishing ratio or the seimaibuai 精米歩合. 

So why polish? Sake made with very roughly polished rice, say 90% remaining, runs the risk of having off-flavours. Shaving off the outer portion of the rice removes the impurities if you will, so brewers today tend to mill to at least 70% remaining.

Although it took around 50 years for it to become widespread, the introduction of the vertical polishing machine, the Seimaiki 精米機, back in 1933, allowed brewers to work with polished rice well beyond the 90% remaining of traditional mills. This helped widen the variety of sake that we now have today. It also led to the birth of highly polished sake, as well as new terminology for describing and categorising sake.

Polishing rates is part of what defines premium sake. Although there is no minimum polishing requirement, Junmai tend to be polished to around 70% remaining. They often have earthy or savoury characteristics with lots of flavour, body, acidity and umami. This is somewhat due to fermenting with more of the outer portion of the rice but also how to brewer chooses to ferment the brew. Polishing further to 60% or less remaining would be classified as a Ginjo style and these tend to be brewed to have a clean and delicate style, often with fruity and floral aromas. Daiginjo is one step further than this and the top tier, with 50% polishing remaining and an even cleaner expression.

So do any brewers work with rice polished beyond 50%?

Asahi Shuzo in Yamaguchi prefecture, brewers of the well-known Dassai brand in Yamaguchi prefecture turned around a faltering company back in 1992 by brewing sake with a record-breaking 23% polishing ratio remaining. Sakurai Hiroshi, the president was determined to produce a refined sake to appeal to discerning consumers in Tokyo and it paid off. It went on to become their flagship product and prompted huge sales growth both domestically and internationally with their sake on the menus of some top restaurants in Paris and New York.

But do they still hold the record for sake using the most highly polished rice? The answer is a resounding NO.

Last year, Tatenokawa, the brewery based in Yamagata prefecture, achieved 1% polishing ratio remaining with 99% of the rice NOT going into the tank to be fermented. For the unprecedented feat with the Yamagata Dewasansan rice variety, it took 1800 hours, around 2.5 months. “Komyo” meaning Zenith in English, went on sale in late 2017 priced at around $1000 for a 720ml bottle, with only 150 bottles produced.

Judging by the price of sake made with highly polished rice, you would think that they are superior in quality. Is Daiginjo really better than Junmai like everyone keeps saying?

Ginjo is often put into the spotlight and defined as high-quality sake with Junmai being mistakenly inferred as an inferior product. Contrary to popular belief, the higher the polishing ratio, i.e. more shaved off, does not equate to higher quality sake, it’s simply one tool of many available to brewers and an indication of the style. 

But why are they so expensive?

One of the main reasons for the high prices of Ginjo is that you simply need more rice, since more is shaved away. Also, brewers often choose to work with more super premium rice types. Other reasons include; a very careful brewing approach such as soaking the rice timed down to the second, slower and more time-consuming fukuro-shibori 袋搾りdrip pressing, and well maybe marketing.  

So to conclude, 1% is currently the lowest that rice has been polished down to and I don’t think anyone is going to beat that record; 0.5% just doesn’t have the same ring to it. And yes, there can be more work involved in producing a sake made from highly polished rice, but it does not equate to quality per se. Musubi, the one that got me into sake, uses completely unpolished rice, is additive-free, brewed naturally with no cultured yeasts, without additions of lactic acids. Surely this is nearer to the definition of premium sake. Just remember, the rice polishing ratio and its associated categorisation does have it limits! Junmai is premium sake just like Daiginjo. 

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