I am talking about rice polishing ratio, that percentage you find on the back of a sake bottle aside from the alcohol content and bottle volume number you see.
One of the most famous sake breweries in Yamaguchi prefecture turned around a faltering company by switching to Junmai-only and brewing sake with a never-achieved 23% polishing ratio remaining back in 1992. It was an incredible feat that saw them grow and the idea was to produce a premium product and appeal to discerning consumers in Tokyo with an eye of the overseas market too.
The percentage on the bottle (the seimaibuai) is the amount of rice remaining and sakes with more taken away tend to exhibit a cleaner, lighter and more refined character, allowing yeast to truly express itself. The majority of Daiginjo’s and Junmai Daiginjo’s on the market are not going for flavour but aroma especially fruity and floral profiles. Shaving off the outer portion of the rice removes the fats, proteins, vitamins, lipids and arguably the impurities, leaving the starchy centre (the shinpaku) but all this hard work can arguably remove all the character too.
Do not be fooled by the steep prices of sake made with highly polished rice; one of the biggest misconceptions with sake is that these are superior in quality. Comparing the rice polishing ratios with the price of a bottle of sake, you would think that it’s true but it’s simply an indication of the style of sake. One of the main reasons for inflated prices of Daiginjo’s (the ones polished to 50% remaining and with added distilled alcohol) and Junmai Daiginjo’s (the ones polished to 50% remaining) is that you simply need more rice the more you polish away. Other reasons include very careful brewing from soaking the rice timed down to the second, colder fermentation temperatures to stress the yeast and bring out those Ginjo aromas (think fruity and floral) and slower and more time-consuming fukuro-shibori drip pressing or filtering at the end and finally, well maybe marketing.
Fast-forward to 2017 and Tatenokawa Inc. back in late 2017 achieved the ridiculous 1% remaining; yes, that’s right, that means 99% of it is thrown out and only 1% is kept to brew. In actual fact, none of the remainder or ‘nuka’ goes to waste, it is usually sold off and has a number of uses such as animal feed. It takes around one hour to polish 60kg of rice to 70% rice polishing remaining and for the never-achieved feat with the Yamagata Dewasansan rice variety, it took 1800 hours, around 2.5 months. “Komyo” meaning Zenith in English, went on sale on October 1st priced at around $1000 for a 720ml bottle with only 150 bottles produced. This is the extreme with rice polishing and they can go down in the Guinness Book of Records now if anyone still reads that. On a serious note though, it is an achievement that should be applauded but just keep in mind highly polished sakes are simply at one end of the sake style spectrum.