The Japanese Sake Bible. Brian Ashcraft
and alcohol levels make the lactic acid bacilli die off, leaving only the sake yeast. The whole process can take four weeks. The result is a robust starter ready to make durable and versatile sake.
The history of kimoto starter
Although kimoto dates from the 1600s, the word does not appear in that period’s brewing manual Domo shuzoki (loosely, “Brewing for dummies”), as the term had not been yet coined. Originally, it was called kanmoto (midwinter yeast starter). At that time, sake was made year-round, with different starters for different seasons. For example, bodaimoto (see page 24) was made in summer, because it thrived in hot weather. The kanmoto style, however, was tailored to saccharify the rice at low temperatures (41–42°F, or 5–6°C). But in 1673, the Tokugawa shogunate banned year-round brewing in a crackdown on sake making. In 1657, it had introduced a brewing licensing system known as sakekabu, essentially a “sake certificate,” which was required for a brewery to make sake. Once the system was instituted, however, the government would not grant new certificates. This allowed it to control the sake business and its rice consumption. Those who hoped to get into sake making had to either buy or lease a sakekabu from a mothballed brewery, although unlicensed sake continued to be made. The government also put a 50 percent levy on sake, causing a drop in production and a spike in prices, resulting in less sake to tax. In 1709 the tax was abolished.
Brewers at Kiku Masamune in Nada mix mounds of rice to prep for kimoto’s moto-suri step. Making kimoto is physically demanding.
However, the seasonal restrictions on brewing would shape sake making for the next several hundred years. It led to rise of the kimoto starter, which by the late 1800s was so dominant that it was known as futsu-moto or “standard yeast starter.” It also gave rise to the toji system, in which a toji (master brewer) and his workers would travel to a brewery, where they would live during the winter and make sake. Since the toji and his team were typically farmers, sake brewing gave them work after the harvest and often ensured that the folks who were making the sake had intimate knowledge of rice. This system worked well until the second half of the 20th century when sake sales dropped and brewery salaries fell with them. Young people left rural areas to live in cities like Tokyo and Osaka, and backbreaking work in cold, damp breweries lost its appeal in an increasingly wealthy country.
The earliest style of kimoto was developed in the Itami area, near Osaka, but was originally mixed by hand, not with oar-like poles. The late 17th-century brewing text Kanmoto tsukuri-yo gokuiden (The essentials of kanmoto brewing), which introduced Itami sake-making techniques, details how brewers mixed the starter using small hand-held paddles in small tubs in a technique called temoto, “hand yeast starter.” Even now rice and water are first mixed together by hand before being mashed with oars in the later stages. However, the pole-mixing technique, which turns the rice into a puree, is not mentioned in this text from the 1600s. That process seems to have been perfected in neighboring Nada during the next century, and it no doubt improved the quality of Nada’s sake.
Yamahai
Around 9 percent of all sake is made with yamahai-style starter. Developed in 1909, this technique omits kimoto’s laborious pole-ramming mashing process. “Yamahai” is short for yama-oroshi-haishi-moto, or “yeast starter that omits yama-oroshi.” Before the 1980s, yamahai wasn’t widely known; it started as an offshoot of the previous decade’s jizake (local sake) boom, which placed importance on older methods.
Process-wise, the difference between yamahai and kimoto happens in the first few days. For kimoto, the starter is mixed in multiple smaller tubs, while yamahai happens in one tank. Yamahai omits the mashing stage, but during the first few days brewers do mix the yamahai batch, using baseball bat–like poles to break up the rice so it can saccharify evenly. These initial mashing steps are how the kimoto and yamahai starter processes differ.
Note that there is also a spin on the yamahai method called kaisoku yamahai (high-speed yamahai) in which lactic acid is added to the yamahai fermentation tank. This isn’t a new process—it dates back over half a century—but it cuts the yamahai starter brewing time in half, saving time and money. Since yamahai doesn’t have a legally defined process, kaisoku yamahai enables brewers to feature the yamahai name, even as they sacrifice flavor nuances. Even with this shortcut though, flavors have more depth than typical sokujo-moto quick yeast starter, making kaisoku yamahai an interesting addition to the brewer’s arsenal.
This shubo yeast starter at the Kasumi Tsuru Brewery is made with the low-foaming version of association yeast No. 7. As is evident from this photograph, low-foam does not mean no foam.
A selection of kimoto sakes.
This Sakura Masamune kimoto sake is made with association yeast No. 1. See tasting note on page 232.
Maruto is a well-made kimoto from Nagano. See page 239.
Under current brewery head Yusuke Sato, Aramasa shifted to all its sake to kimoto. See page 215.
Are kimoto and yamahai different?
Yamahai is said to produce much gamier or wilder flavors than kimoto because it doesn’t use kimoto’s pole-ramming method, which affects saccharification, so more funky compounds end up in the starter. But according to Kazuhiro Fukumoto of the Kasumi Tsuru brewery—one of the few in Japan to brew exclusively with kimoto and yamahai starters—the difference between yamahai and kimoto is more nuanced.
“If you are making kimoto and yamahai, they end up resembling each other,” says Fukumoto. “That is if your brewery is like ours, and is trying to offer kimoto and yamahai at their best.” What he means is that at Kasumi Tsuru, there is a difference between kimoto and yamahai sake, but the difference is clearly understood. “Yamahai is easier to drink when freshly pressed, which is why we sell it that way,” says Fukumoto. “Newly pressed kimoto has a hard mouthfeel and a mineral taste, especially if the rice isn’t polished to less than 60 percent.” Kasumi Tsuru feels its yamahai is better young, while its kimoto can be put down for a year,. “But if the yamahai and kimoto are highly-polished ginjo or daiginjo sakes, there really isn’t this difference.” This discrepancy might be due to the way the fats and proteins in less-polished rice break down.
Tools called kaburagai are used to make kimoto. The ones pictured here are used by the Kasumi Tsuru brewery in Hyogo Prefecture.
This certainly doesn’t mean yamahai doesn’t age well. On the contrary, Philip Harper at the Kinoshita brewery (see page 127) is making excellent aged kimoto and yamahai sakes.
A selection of yamahai sakes.
Yuki no Bosha from the Saiya Brewery in Akita. See page 231 for tasting note.
This Tenon brew is a rich, well-balanced yamahai. See page 227.