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 fits the staves together.
With taga hoops holding the staves in place, Tamura shaves the cask’s inside.
Tamura works with a two-handled drawknife called a sen.
The cooper pounds the cask’s lid, which is known as a kagami.
THE SEASONS OF SAKE
Sake has long reflected seasonality. The brewing season season starts in fall and ends in early spring, although many producers these days brew year-round. Traditionally, brewers worked in fishing or agriculture, whose low seasons coincided neatly with the sake-making season. Even further in the past, however, sake was made throughout the year. Different seasons meant different styles of sake as well as varied production methods. For example, the bodaimoto (aka mizumoto) yeast starter was developed at a Buddhist temple by the 1300s, so monks could brew sake during the summer with fewer batches going to rot. But kanshu, sake brewed during the winter, was the most expensive.
In 1673 the Tokugawa shogunate restricted brewing to the winter to ensure a stable rice supply and create seasonal brewing labor. The seasonal brewers became a staple of sake making until the late 20th and early 21st centuries, when production dropped significantly and more rural young people either migrated to cities or lost interest in the low-paying, backbreaking work of sake brewing, which required them to be away from home for months at a time.
But sake brewing is suited to cold weather. Steaming, koji making and fermentation give off natural heat, which is easier to manage in the winter. Temperature control is one of the most important elements in sake production. Before refrigerators and air-conditioners, winter brewing made this easier. If brewers needed to adjust the temperature of the yeast starter, they could add a dakidaru (a water- or ice-filled container). Analog temperature control wasn’t only important in the winter. The outside walls of breweries were painted white to reflect light, keeping things cool.
With the advent of refrigeration during the 20th century, sake breweries were able to stay in production throughout the year. Year-round breweries were built in Hawaii and Taiwan at the turn of the 20th century, as the warmth of the local climates made batches of sake susceptible to rot-inducing bacteria. In 1961, Gekkeikan in Kyoto and Reimei Shuzo in Nagasaki each built Japan’s first year-round breweries to meet the demand of the nation’s skyrocketing population.
A line-up of fall-release sakes. To learn about the different subgenres reflecting the micro-seasons of Japan’s autumn, see facing page.
Limited-release summer sakes. The tags recommend serving these brews chilled. The bottles are blue
