If your holiday shopping list includes any serious home cooks, there is probably nothing you can get them that will be as useful, or as appreciated, as a high-quality knife. But buying chef's knives is hardly a straightforward matter—indeed, the world of knife-making is its own complicated and fascinating design niche.
Recently, I set out to learn more about the design of Japanese knives, which have become increasingly widely available in the United States through brands like Shun and Global. [Editor's Note: Our own Hand-Eye Supply offers a few options from the more obscure Midori Hamano.] Not surprisingly, Japanese knife manufacturers take their craft very seriously. Shun, for instance, describes its blade as "a way of life"—and the name Shun (rhymes with "moon") is derived from a Japanese word that refers to the moment when a piece of fruit is at its sweetest, the peak of perfection.
This perfectionist approach trickles down to every aspect of the Japanese knife manufacturing process, which traces its roots back to the blade-making tradition of ancient samurai swords. Companies like Shun and Global pride themselves in the fact that none of their knives leave the factory untouched by human hands, as the final balancing process requires a myriad of hand-working techniques by skilled craftsmen to achieve the ideal weight.
Weight is one of the key areas where Eastern- and Western-styles knives differ. Eastern knives tend to be balanced with the weight in the blade, allowing for quick and easy chopping with no additional pressure. The Chinese cleaver is an excellent example of this, having a rectangular blade and a slight curve for easily mincing and dicing food using only a slight rocking motion. Western knives, more often, are neutral-balanced, meaning that the center of gravity exists at the "pinch point," or where the blade meets the bolster. This allows the chef to pinch the knife between the blade and the handle.
"Think of how a sushi chef works," says Tommie Lucas, the product development manager in the housewares division of Kai USA Ltd., the Stateside division of Kai Group, which manufacturers Shun cutlery. "They swiftly chop tons of fish and vegetables into clean, tiny pieces. That cut needs to be as seamless as possible and, since it's so repetitive, the motion needs to be easy and effortless."
Of course, the balance isn't worth much if the knife doesn't cut beautifully, and Japanese knife designers pay equally obsessive attention to the blade itself. This requires a particular understanding of what materials are used and how they are sharpened. The performance-cutting blade steel is the most important; this is the center blade that is actually used for cutting and slicing. Shun used to forge its blades, but it has abandoned that practice due to the fracturing and impurities that would often occur; instead, it now employs rolling processes to create sheets of steel which are then blanked (stamped) or laser-cut to create the center blade.
A diagram from Shun. Click the image to view a larger version.A diagram from Shun. Click the image to view a larger version.
Shun knives are clad in Damascus steel, a type of steel known for its use in Middle Eastern sword-making. After the knife is heat-treated, the blade is rough-ground using a CNC-controlled grinding machine before hand-working takes over. Knife smiths continue grinding at a six-foot tall grinding wheel before welding on the bolster. The blade and bolster are then riveted or mechanically attached via the end cap to the handle, a birch wood impregnated with resin to keep water out and to prevent the grain from expanding and contracting. (Fun fact: the birch is the same that is used for prop-plane propellers—a testament to its strength and durability.) The final blade is hand-sharpened on a whetstone before being packaged and shipped out to chefs around the world.
Throughout this process, the knife is being carefully balanced and weighted, and material is removed from the hollow of the bolster and the end cap of the handle to reach the optimal balance. Global's knife artisans go so far as to hand-pour sand into their handles to achieve the perfect weight.
Ironically, Lucas says, "Americans often perceive the lightness in weight as a cheapness of the product." If you have been guilty of this grave misconception, consider yourself corrected—in Japanese knife-making, as in so much other Japanese design, what may seem simple or straightforward is in fact the product of careful consideration and extreme attention to detail.