Saké making is a highly detailed and rigorous process, requiring expertise at every stage. Although this diagram does not do justice to the process, one an simplify saké making into the following major steps:
Sakamai - Saké rice
Saké rice is planted in May or June and cultivated in August or September. Although there are no vintages for saké, there are “good years” and “bad years” for rice. Typhoons or excessive rain are the biggest enemies, but master saké makers can adjust to these conditions and produce saké of excellent quality.
Seimai - Rice Polishing
In the first stage of saké making, the brewers mill the rice to its heart in a process called seimai. Seimaibuai, or rice-polishing degree, delineates levels of saké. Milling the rice removes the fats, proteins and amino acides from the outside of the rice grain, leaving the starches at the center. The more the starch-filled center is isolated, the more elegant and refined the saké will be.
Senmai - Rinsing
The first layer of rice powder that is milled away is used for feed. As the rice is brown at the beginning, this powder is too. The powder produced from the next round of milling is used to make rice crackers, or sembe, and other food products.
After milling, saké makers rinse the rice to remove the powder that is left on the grain. At the same time, saké makers also soak the rice. This prepares the rice for the next stage, steaming. Depending on the type of rice and its milling level, rinsing and soaking are done with stop-watch precision, literally.
Jomai - Steaming
Saké rice is not boiled like table rice, but rather steamed in a koshiki. If the rice is not steamed enough, it will be too hard for the next step to go right. If it is steamed so much that the rice is mushy, then certain, necessary enzymes cannot be produced. After steaming, the rice is allowed to cool.
Twenty to thirty percent of the steamed rice is used for koji, while the remainder is mixed in with the koji rice at the beginning of brewing, or fermentation.
Koji making is the soul of saké making. The room in which the koji is made, the muro, is the heart of the brewery. So what exactly is koji? It is a mold that converts the complex sugars in rice into simple sugars. To make “koji rice,” the brewers sprinkle koji powder on a portion of the steamed rice.
Over the next forty-plus hours, they knead, wrap, unwrap, spread out, and cool this rice. By the end of the process, the rice is 100-percent simple sugar and has a white, frost-like coating. Its aroma is reminiscent of roasted chestnuts.
Moto or Shubo - The yeast starter
The names for the yeast starter, shubo and moto, meaning “saké mother” and “foundation” reflect the importance of this step. Essentially, the yeast-starter is a highly concentrated “mini batch” of saké, consisting of koji rice, water, yeast, and steamed rice. There are three ways to make the yeast starter, kimoto (the original way), yamahai (the second way) and sokujo (the modern, fast way).
There are also 50 different kinds of saké yeast, with 15 major types. Some were developed in certain regions, others by particular breweries; some yield light and refined saké, others bolder and more intense flavors.
San-dan shikomi - Three-step brewing
Once they have made this concentrate, the brewers start the fermentation process by adding these ingredients three times, multiplying the amounts by two each time. In this process, called shikomi, the koji rice goes to work on the remaining steamed rice, converting its starches into simple sugars in a process called “multiple parallel fermentation.” After this, the brew is on its way into fermentation, which takes eighteen to twenty-five days.
Moromi - Fermentation
After all this action of milling, rinsing, soaking, steaming, making koji, making the moto and brewing it in three stages, the brew begins fermentation. Although there is less active labor in this process, the brewers must repeatedly and precisely control this process. Fermentation takes 18 to 25 days and constant attention and adjusting.
Joso - Pressing
After fermentation, the kurabito, or saké makers, press the moromi. Most saké is pressed in a large accordion-like machine called a yabuta.
In a more specialized process, the kurabito fill cotton bags with the finished brew and then place the bags in a boat-like vessel called a funé. Freshly brewed saké then gently seeps out of the bags to a drain at the bottom of the funé. As it finishes draining, the saké makers gently press down with a flat lid that pushes out more saké.
In the most refined process, called shizuku, or “drops,” the brewers hang the cotton bags on bamboo poles and let the saké drip into a smaller tank. Shizuku saké is fresh, light, and elegant
Roka-Filtration and Bottling
After pressing, saké is filtered, pasteurized twice, and stored in bottles, or tanks to be bottled later. Saké is brewed from the beginning of October until the end of March and, generally, released six months after storage.