Japanese Chef Knives 101
by Lee Baldwin
Fine Japanese Chef Knives and their uses
Japan’s reputation for fine cutlery rivals or arguably surpasses the generally acknowledged world leader, Germany. Combining modern materials, precision manufacturing, and traditional designs, Japanese knives are prized by professional chefs around the world for their ease of use, although some require specialized skills. They tend to be thin, stiff, well balanced, stay very sharp, make very precise cuts, and resist sticking to food. Home cooking enthusiasts in the West are discovering them for the same reasons, as well as their unique eye- catching shapes and finishes. After all, showing off your new toys is part of the fun of entertaining!
Japan has long maintained a reputation for excellence in metalworking, both for weaponry and jewelry. The traditional art of sword making took a serious blow in the late 19th century when Emperor Meiji, in an effort to modernize Japan, prohibited his Samurai warriors from carrying swords. The majority of the swordsmiths in the ancient armory cities of Miki, Seki, and Ichizen turned to cutlery. The center of the modern kitchen cutlery industry is in Seki, where the October Cutlery Festival is a major industry event.
Two methods were developed to make a sword, and both were adapted to kitchen knives. The older variety is honyaki. These knives are forged from high carbon steel. By using elaborate processes of forging (hammering) and
tempering (heating and cooling), this metal can develop the highly prized quality of kirinaga, the ability to hold a very sharp, long lasting edge. One problem with carbon steel is that it tends to be brittle. To make up for this, Honyaki knives
tend to be thick, and the tempering process is demanding.
To get around this problem, the more advanced kasumi technique was invented,
and quickly became the preferred type of Samurai sword. Two kinds of steel were forged together, to make a hardened edge supported by softer, tougher low-carbon steel, or even soft iron, for the body of the blade. Making kasumi blades requires more skill for forging, and they can be thinner, and therefore
lighter. The Damascus process extends this technique, using many layers of steel to achieve extra toughness, and produces a wavy, ornamental finish.
Both methods are still in use, although modern steels are now common, with tough stainless and high strength alloys replacing the rust-prone carbon steels. It’s generally agreed that the alloy with the highest kirinaga is VG-10, a high carbon stainless steel developed especially for chef knives. Today, almost all blades made from this alloy are manufactured in Japan.
Carbon steel requires more care than stainless alloys, and not just because it can rust. When freshly sharpened, the exposed metal is chemically reactive, and can give food a metallic taste. Traditionally, a chef sharpens and oils his knives at the end of the day so they can develop a patina overnight. Some chefs go so far as to have two sets, which they alternate from day to day.
Japanese chef knives were developed mainly for slicing or chopping raw fish and vegetables, and have unique designs that make them particularly efficient for these tasks. Unlike European knives, they are often single ground (kataba), where only one side of the blade is angled. This makes it possible to produce very thin, precise slices, but requires more skill to use. Ryoba, or double ground blades are also made, mostly for home kitchens and the export market.
Single ground blades come in the standard right-handed version. Left-handed knives are rare and generally custom made. 18 to 30 degree sharpening angles are typical, much like European blades, although for similar uses, Japanese blades tend to be honed to a more acute angle. Sushi knives are sharpened as acutely as 10 degrees, less than most razor blades. This sharpening process is
very demanding, requires the highest quality steel, and the delicate edge requires extreme care to prevent nicks, chips, and blade rolling.
Subtle variations on the chisel grind reduce adhesion of the food, permitting
clean separation of thin slices. One technique is urasuki, a slight concave curvature on the back of the blade. Another more recent technique is the
Granton edge, a series of scalloped indentations above the front side, also known as a hollow edge.
Because traditional knives require careful maintenance and a high level of knife handling skills, Japanese chefs own and jealously protect their knives to a greater extent than in the West, and are more willing to spend lavishly for high quality. Professional sharpening is generally recommended.
Japan produces the full range of quality and price for the export market. Kasumi blades, especially the laminated Damascus ones, are superior to single forged honyaki blades, which are usually considered better than blades produced by stamping. Better knives have full tangs, stronger assembly techniques, better balance, and in particular, higher quality steel. At the high end, custom knifesmiths achieve fame for their artistry and craftsmanship.
A basic set of knives includes the deba bocho, a cleaver, the santoku hocho, or general purpose knife, and the nakiri bocho, or vegetable knife. In addition there are dozens of styles, each specialized for individual tasks such as filleting tuna, shelling crabs, slicing sashimi, or preparing noodles. Recently the gyuto, or French chef’s knife, has become popular, and with it the easier-to-use double ground edge, which is now common in santoku knives.
The most iconic and widely used of the Japanese chef knives is the Santoku, which means three virtues, referring to slicing, dicing, and mincing. It is a versatile general-purpose knife used for meat, fish, or vegetables. The back is strait edged for scraping food off a cutting board, and the handle is aligned with the top of the wide blade. It has a sheepsfoot or drop point shape, known in Japan as kamagata, or Osaka style, which limits the danger of accidental puncturing, and little or no curvature of the edge, which allows precise long slices. This limits the rocking motion more commonly used by European chefs, and is used with a firm chopping motion, often from heel to tip. Balance is important, with handle and tang matching the blade in width and weight. 5 and 7-inch blades are the most common, although other sizes are available.
Gyuto, which means cow blade, are larger than Santoku, and modeled on the
French chef’s knife. They were adopted for cutting beef, and for the easier to master double ground edge. They tend to be thinner than European knives, and sharpened more acutely, which is made possible by using harder, tougher steel alloys.
Deba Bocho is a heavy duty cleaver, with a wide, thick blade and handle even with the non-cutting edge. They come in Tokyo style, with a rectangular end, Osaka drop-point style, or most commonly, with a piercing tip. They are sharpened more obtusely than other knives to stand up to chopping through fish bones. Numerous variations are made for specific tasks, such as reverse-angled blades for removing crab shells without cutting the meat.
Nakiri Bocho are general purpose vegetable knifes, double ground for home kitchens. Like the deba bocho, the handle is aligned with the non-cutting edge. The blade is thinner, and the edge may have a slight curve. The ends may be rectangular, sheepsfoot, or pointed. Traditionally they have a black patina finish, which may be mimicked with a coating applied over modern stainless.
Usaba Bocho is the professional version of the nakiri bocho, and has a single
ground edge for greater precision.
Kurimuki means chestnut skin peeler. It is a vegetable knife especially designed
for small items.
Maguro bocho, hancho hocho, and oroshi hocho are long and flexible, for filleting large fish. Some reach 6 feet in length. Gishiki Bocho are used for a method of rapidly filleting small or medium sized fish, holding the fish with chopsticks. Since their uses are so specialized and difficult to master, they’re seldom found in home kitchens or outside Japan.
There is a wide variety of specialized sushi or sashimi knives – sashimi bocho — for slicing specific kinds of raw fish. They tend to be long, thin, flexible, and sharpened to very acute angles.
Many have sharp piercing tips. Among these are the yanagi ba, (willow blade),
Yanagi ba (Willow Blade)
the tako hiki, (for octopus, featuring a square point), fugu hiki (for pufferfish), and
unagisaki hocho (for eel) Soba Kiri and Udon Kiri are for preparing soba and udon noodles.
This report covers the basics of Japanese chef knives. For those who want to
delve deeper into the subject, I recommend Japanese Kitchen Knives by
Hiromitzu Nozaki.
Japanese Kitchen Knives: Essential Techniques and Recipes
by Hiromitzu Nozaki.
This thorough, well written, and beautiful book is by far the most complete reference available, and in addition to describing the history and wide variety, it includes detailed instructions for proper use, care, storage, and sharpening.