Different styles of sake age differently. From left to right: a kimoto junmai from 2014, a junmai-shu from 1991, a junmai-shu from 1973, and a honjozo from 1973.
If there is no interaction with wood, where does Sawanotsuru’s koshu get its amber and brown hues? “A big difference between sake and distilled spirits is that if you leave, say, whisky alone, it won’t change color. Sake will.” The reason, says Konno, is that distilled spirits do not have components that will change color. “Sake changes its hue by simply leaving as is, because it has amino acids, organic acids and sugars.
“But after that, the sake starts to mature nicely, becoming richer and changing color as sake sediment collects at the bottom of the tank,” says Konno. “All that intensity reaches a peak, and then the sake settles down and becomes smooth and crisp to drink.” These changes happen over decades, and the brewers don’t just leave the sake to age in a temperature-controlled room. They check the flavors annually. Furthermore, every decade, depending on how the sake is maturing, they remove some—but not all—of the sediment, which consists of rice and yeast particles and other material, in a process known as oribiki, or “sediment removal.” The koshu is then placed in a new tank. “Here is the oldest batch in this maturation room,” Konno says, pointing to the date on a tank.
“Compared to vintage wine and old whiskies, koshu isn’t expensive at all,” says Konno. “That’s because people in Japan don’t yet fully appreciate its value.” Drink up while you can, because one day, that might change.
The Nada-gogo brewing district in Kobe is famous for its hard water (for more, see pages 90–91). However, its success was also due to local rivers like the Toga River (pictured) that helped power the waterwheels that made previously unseen rice-polishing rates possible for delicious sakes.
Hiroyuki Konno fills a glass with Sawanotsuru’s vintage sake.
THE MASTER CASK MAKER
“I’ve been making casks for over 30 years,” says master cooper Takeshi Tamura. Using a blade, he splits a long strip of bamboo down the middle. His movements are practiced and precise. He then takes the strip and whips it round like Indiana Jones. In seconds, he’s made a perfect hoop called a taga. Apprentices spend months mastering these motions before they begin making the actual cask. “You start with the taga,” Tamura says. “If you can’t learn that, then you can’t move to the next step.” Today, Tamura is making about 10 casks for Kiku Masamune brewery’s taruzake (cask sake).
Since its founding in 1659, Kiku Masamune has been making taruzake. Before the 20th century, taruzake was commonplace. If you were drinking sake, it was most likely transported and stored in wood. Today, most sake breweries don’t make taruzake, and the ones that do typically don’t make their own taru, or casks. Before glass bottles appeared in the late 1800s, sake was carried in taru casks from Nada in western Japan to modern-day Tokyo via ships known as tarukaisen, which literally means “cask cargo vessels.” It would take around 12 days to transport the casks from western to eastern Japan. Once the sake arrived in Tokyo, liquor shops would keep it in the casks it was shipped in. Storing the brew in cedar casks added extra flavors.
During the 20th century, when other breweries moved away from cask maturation, Kiku Masamune continued making taruzake, even during the Second World War, when the confusion and chaos pushed aside time-consuming and expensive traditional methods. In 1966, the brewery launched a bottled version of taruzake that is still sold today—in 2017, it produced 1,180 kiloliters (311,723 gallons) of the stuff. For Kiku Masamune, one of the biggest breweries in Nada, cask-aged sake is a signature part of its lineup. For the sake industry as a whole, though, it’s still a niche product, because most breweries are unable to employ master coopers. Kiku Masamune, however, makes all its casks in-house, thanks to the increasingly rare skill set possessed by Tamura and his fellow coopers. “Taruzake is a lot of work,” he says, “but it’s worth it.”
Tamura begins fitting 16 staves, called kure, in place. Japanese casks are much smaller than their Western counterparts, holding 72 liters. The small size allows greater interaction between the brew and the wood. Kiku Masamune stores its sake in casks for a brief time, but does not ship it in casks; its aim is to flavor the brew with sugi, or Japanese cedar.
“We always make our casks from Yoshino sugi,” Tamura says, holding up a stave. “I’ve only ever made casks from that sugi.” Yoshino, a small Nara town with less than 10,000 residents, is famous for two things: cherry blossoms that have inspired centuries of Japanese art and poetry, and high-quality sugi cedar with a long grain and no knots. Only Japanese sugi that are over 100 years old are large enough to be turned into cask lumber.
The wood has a fresh, green aroma. “That’s the scent of the organic compound terpene,” says Toshinari Takahashi, the production manager at Kiku Masamune. This brings out the refreshing dryness of Kiku Masamune’s sake. It also has a sharp taste, so the sake only gets a quick finish in the casks for two or three days; any longer might make the brew overwhelming for modern tastes.
Tamura turns over one of the staves, showing the side that must line up perfectly with the stave next to it. “This side is called the shojiki surface,” pointing to the side. “Shojiki” means “honest,” “upright” or “frank.” The word perfectly describes the approach to Japanese cooperage. Before the staves are fitted in place, their sides are shaved with a special plane called a shojiki-dai, so that they fit together, which also releases the flavors in the wood. Glue and nails aren’t used, so everything needs to line up perfectly.
With a couple of thwacks, Tamura hammers two taga hoops into place, flips the cask on its side and begins shaving the inside to make it smooth and uniform. The staves are various heights, with some jutting up slightly higher. Flipping the cask over again, Tamura takes a two-handled drawknife called a sen, lays it against the edge and pulls it toward his body, making the top edge even and sending little wood chips flying. He takes a cask head, or lid, bending it slightly, and then pushes it flat into place at the top, sealing the cask, before hammering on four more taga, shaving the bottom staves so they align perfectly, and then putting in one last taga.
When the cask is finished, it’s ready to be taken into the filling room, where it’s filled with sake for a quick two-week maturation, enough to give the sake elegant forest notes without overpowering the brew. Since only fresh casks are used, once the maturation is finished, casks are resold to shops that make tsukemono pickled vegetables.
Tamura stops, wipes his brow. This is the first cask of the day; only 10 or so more to go.
Takeshi Tamura