Kiso is a richly wooded land. Located in the center of Honshu, Japan’s main island, the mountainous region boasts an abundant supply of lumber that has spawned a diverse range of woodcrafts made by skilled practitio-ners well versed in the seasonal cycles of the forest.
Many parts of Japan have cultivated woodlands where hinoki cypress is grown. Only in Kiso, however, does one find natural forests that are home to wild hinoki trees over 300 years old. Filled with that fresh and characteristically uplifting scent, these magnificent stands of towering trees are a symbol of Japan’s long cultural association with wood.
It’s no surprise that Kiso has many woodworking traditions. One of its products is hangiri, the wooden tub used to mix vinegar and salt into freshly steamed rice for sushi. Indispensable to proper sushi making, these tubs are crafted of sawara cypress by Shimizu Mokuzai, a workshop nestled deep in the Kiso hills. The company marked its 71st year in 2014.
Of the same family as hinoki, and growing alongside it in the same forests, sawara is counted as one of Kiso’s five major kinds of trees. Hiroki Shimizu, the third-generation owner of Shimizu Mokuzai, explains the difference between them: “Fragrant hinoki is the standout favorite for wooden baths. But a rice tub made of it would perfume the rice too strongly. Sawara, on the other hand, lends a much milder scent to the rice, and those who prefer no fragrance at all can easily remove it by soaking the tub in diluted vinegar for two to three hours, then rinsing it with water.”
The lumber for Shimizu’s hangiri tubs is culled from cultivated forests. In general, wood grain that shows closely set annual rings is said to be of superior quality, but Shimizu points out that there is another consideration that bears on the right choice of material for rice tubs. “Trees grow quickly in a man-made forest, as they are planted to get plenty of sunlight. Typically they get broadly spaced annual rings as a result. But the lighter-colored sections amassed over the fast-growth summer seasons have excellent moisture-absorbing properties. That’s why sawara trees grown in a cultivated forest are best for this particular item.”
Ki o yomu is a Japanese phrase that literally means to read a tree, or a piece of wood. It is a fitting expression for the work that craftsmen such as Shimizu and his team of 22 employees do. Handling wood daily, they know the material’s characteristics inside and out, and reflect that knowledge in each of the products they make, whether sushi tubs or bath tubs.
Demand for its hangiri rice tubs is so high that the company cannot keep up with the orders. On any given day some workers will be cutting logs into planks, some matching parts for color and grain, and still others planing each product’s surface to a smooth finish. Though a good
deal of the process is mechanized, much of the work demands skilled hands.“Each piece of the material is different from the next, and that’s where a woodworker’s skills are needed,” Shimizu says. “Machines are fine for rounding off a plank or polishing a rough surface, but only a carpenter with a practiced eye can determine whether planing is best done from which side, or discern fine shadings of color or other aspects that affect quality.”
The sapwood or white outer layer of sawara tends to discolor easily. Some lower-priced rice tubs on the market are fashioned partially of sapwood, but Shimizu Mokuzai uses only the more durable heartwood— the dense inner part of a tree. As heartwood has faint reddish tints, workers carefully match up similarly hued planks, always with an eye to aesthetics.
We asked Shimizu for tips on the proper care of a hangiri tub. “A common problem is mold, but this can be easily prevented,” he says. “The tub should be rinsed out after each use, and wiped dry with a towel. Some folks make the mistake of thinking it will dry if left on a draining board, but in fact the wood will only absorb the moisture. But putting your tub in a sunny spot to dry isn’t recommended either, as the wood will shrink and the hoops loosen. As long as you wipe down the tub with a clean absorbent towel, making sure that the surface is dry to the touch, it will be fine. Then, store it in a box. If cared for in this way, mold and discoloring should never be an issue.” Some tubs brought in for repair have been used for so long and so often that the bottoms have holes where the cook’s wooden spatula repeatedly struck as it cut through the rice. “Those cases make us really happy,” he beams.
All stages of wooden tub production progress simultaneously. A number of machines hum steadily, but certain pivotal steps are done manually with great care by skilled craftsmen. Only the hands of a woodworker with seasoned years of experience can pass over a surface to find the slightest area that requires smoothing. In the photo at top right is Shimizu Mokuzai president Hiroki Shimizu.