Technology improves the old grinding stone
By JOHN GAUNTNER
Over the years, every step in the brewing process has been subject to a barrage of so-called technical advances. More often than not, though, these modern technologies are not as good as the traditional methods they replace.
Some developments save so much time, labor and money that a small dip in quality is tolerated. Others are good for making mass-produced, cheap stuff, but too much is sacrificed to permit the brewing of premium sake. Often, the old, hard, traditional methods and tools are best.
But there is one step in the process in which, it is universally agreed, modern technology has helped make vastly superior sake: rice milling, or seimai. Until around 80 years ago, rice milling was not very accurate and was rough on the rice. Brewers had no accurate way to measure how hard they were grinding, and much of the rice was crushed in the process.
In fact, long ago, rice was milled using a mortar-and-pestle type of method, in which dry rice in a small tub was pounded with a special stick. This yielded to machines driven by waterwheels next to rivers, and then to various manifestations of large, spinning drums.
Then, in 1933, the vertical rice-milling machine was invented. This was recognized as a quantum leap in rice-milling technology, and the quality of sake jumped along with it. Since then, things have only gotten better, and a variety of milling technologies are used in combination today.
How do they work? In one typical method, the rice is lifted to the top of the several-meter-high machine before being dropped through two spinning grinding stones. It then goes up again and down through the grinding stones again, over and over, with the ground-away powder being vacuumed off. The weight of the rice as it passes through is compared with the weight of the original rice to determine how much has been milled away.
But why all the fuss? What is there to be so careful about? Several things are important.
One is heat. With all those rice grains bumping into each other there is bound to be some friction. The heat generated by this friction can significantly dry the rice grains, making them vulnerable to cracking and breaking. The more slowly the rice is milled, the less friction and heat are generated.
Another is accuracy. When milling rice for the highest grades of sake, extremely precise and specific milling levels are targeted — usually within 1 percent. Only modern, computer-controlled precision machines can handle that.
I once met a very old brewer who determined the degree of milling by using a stethoscope to listen to the sound of the rice as it spun over in the horizontal rotating drum of the archaic milling machine being used. He was actually the retired president, but no one else had the expertise for the job as he had been doing it for 40 years and had it down pat. I hope they have upgraded their system by now.
As many readers may be aware, rice is milled to remove fats and proteins in the outer portion of the grains, leaving only the pure starch centers behind. This produces sake that is fragrant, complex and elegant. The more the rice is milled, the more refined and graceful the sake becomes. While table rice is milled so that the outer 10 percent is removed, some sake is made with rice that has had a whopping 65 percent ground away.
The importance of this step in the production process should not be underestimated. The ability to mill rice gently and with precision is one of the most significant reasons for today’s sake being as good as it is.
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Kariho (Akita Prefecture)
This small kura focuses on quality, so much so that only one out of the 110 tanks they brew each year is not premium sake. The water here is slightly harder than is usual in Akita Prefecture, leading to a relatively dry sake, but with a pleasing, full flavor across the palate.
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