Japanese kitchen knife

Japanese kitchen knives are knives made in a fashion that adheres to varying degrees to the traditional techniques of Japanese blacksmiths. Most knives are referred to as hōchō (Japanese: 包丁/庖丁), or sometimes -bōchō (due to rendaku), but often have other names including, -kiri (〜切り, lit. "-cutter"). There are four general categories to distinguish the knife design: handles (Western vs. Japanese), blade grind (single bevel vs. double bevel), steel (stainless vs. carbon), and construction (laminated vs. monosteel).

Handles

Western handles have a bolster and a full or partial tang. These knives are often heavier, but smaller in volume and surface area than most Japanese handles. The scale materials are often synthetic or resin cured wood and nonporous. Chefs who prefer a grip closer to the blade, a balance closer to the handle, more weight in the cut, or specific cutting techniques associated with them often prefer the feel of a Western handle. The handle is lighter and greater in volume than most Western counterparts.

Japanese handles are made of ho wood burned in and friction fitted to a hidden tang with a buffalo horn bolster capping the handle-blade junction to prevent splitting.^[1] This allows easy installation and replacement. The wood is porous and fine-grained so as to not split and to retain grip when wet. More decorative woods such as ebony, yew, cherry, or chestnut (often charred on the outside to improve grip and water resistance) are also used and are heavier. Some of these woods are more prone to cracking if not well cured or properly cared for when exposed to humidity. A silver colored metal spacer is sometimes seen on ebony handles to celebrate the completion of a chef's apprenticeship.

The general shapes are chestnut (or D) and octagon, among other variations of these shapes, with most tapering slightly larger toward the tail end. Some smooth the ho wood handles as they can retain particles of dirt or sharpening swarf and discolor. Chefs who prefer a more blade-heavy knife, a lighter knife, a larger handle for otherwise cramped hands, lower cost, or easily replaceable handles often prefer the Japanese handle.

Chestnut (or D) shape
Octagon shape

Blade grind

Double bevel knives are those made in the Western tradition. These knives are generally thinner at the spine but often thicker behind the edge and are made to not steer left nor right during the cut. They do not require as much care or knowledge to perform adequately as single bevel knives. Japan adopted French and German cutlery ideas after World War II and hybridized them to fit Japanese cutting techniques and culture. Japanese knives are often flatter than their European counterparts.^[2]

Gyuto: (literally beef-sword) The chef's knife for professional Western cuisine. For vegetables, it is used to chop or thrust cut like a nakiri near the heel, to rock-chop stiffer produce in the belly, and to make fine cuts at the tip. For meat, it is used to saw back and forth for large cuts, to pull cut for softer meats; for a better surface finish, and to push cut for more sinewy meat. There is usually a slope from heel to the tip which causes the wrist to point down and shoulder to raise up to make cuts. General size is 210 mm to 270 mm. 210 is more of a line knife size and most nimble, 240 is more of a general purpose size and allows more slicing, and 270 has more slicing power but is much more cumbersome, being the tallest and longest.

Santoku: (literally three-virtues), also called bunka bocho (literally culture knife), prioritized for vegetables and fish. These are generally flatter than gyuto and have a less pointy tip. Because they are flatter, the wrist is in a more natural position and the shoulder does not need to be raised as high. These knives do not require as much room to cut, however, these knives are not used when doing Western cutting techniques that may require more room such as a gyuto knife would. These are the most popular knives in most Japanese homes. General size is 165 to 180 mm.

Nakiri: (literally vegetable knife) The square tip makes the knife more robust and secure feeling than the pointed santoku and gyuto, as well as allowing it to cut dense ingredients at the tip. This knife usually has a flat edge. Some varieties of a nakiri have a slight tilt to the blade profile toward the handle. This is to make the grip more comfortable which makes the hand tilt up slightly and uses the muscles under the forearm. Popular alternative to the santoku. General size is 165 mm to 180 mm.
Petty: A smaller knife to accompany gyuto for in-hand paring work or for produce at a scale that much smaller than gyuto. General size is 120 mm to 180 mm.
Sujihiki: (literally muscle cutter) These are long knives to cut meat, often in a draw cut. General size is 240 mm to 300 mm.
Hankotsu: A butchering knife for cattle to cut hanging meat around bone. General size is 150 mm.
Chukabocho: Chinese chef knife. Short handled, flat profile, and tall to gain mechanical advantage. Usually thicker behind the edge to cut denser ingredients and sometimes bone.

Single bevel knives are knives made in the Japanese tradition and have an omote (front or face on the right for right-handers), a shinogi (where the front bevel meets the flat of the blade face), and a urasuki (backside hollow to release food). These knives are usually a little thicker at the spine and body than Japanese double bevels but are thinner right behind the edge. They leave a better surface finish but the produce must bend a further distance due to the thickness. These are the knives of the established traditional Japanese cuisine and were originally developed from double bevel knives from China. They are sharpened along the single bevel by applying pressure to the shinogi to raise it and to the edge. Honbadzuke is the initial sharpening to form a flat surface along the perimeter of the urasuki to strengthen it, straighten the backside, and lay geometry for future sharpening. The omote is sharpened much more than the urasuki in order to maintain the function of the single bevel. Kansai style knives usually have pointed tip for use standing up (which helps in decorative tip work) and Edo style knives have a square tip for use sitting down (which makes a more robust working knife). The standard Japanese knife kit includes the yanagiba, deba, and usuba. They are essential to Washoku (Japanese cuisine).

Yanagiba: (literally willow blade). The most popular knife for cutting fish and also called shobu-bocho (sashimi knife). It is used to highlight different textures of fish in their techniques: hirazukuri to pull cut vertically, usuzukuri to pull cut thin vertically, and sogizukuri to pull cut at an angle. It is used to skin and sometimes scale and de-bone certain fish (for instance salmon). Kensaki or kiritsuke tip yanagiba have an angled tip and are generally heavier and less sloping. A regional variant, takohiki (literally octopus cutter) is lighter, thinner, flatter, and shorter in blade height than yanagiba to allow easier cutting through dense flesh as octopus. General size is 270 mm to 330 mm.

Deba: Thick knives to cut through resilient fish flesh for fillet and to cut through rib bones, behind the head, and through the head. They are 5mm to 9mm thick depending on size. They include hon-deba (literally true deba), ko-deba (small deba), ajikiri (for aji), funayuki (a smaller more pointed for use on boats), and mioroshi deba (hybrid between deba and yanagiba that are intermediate in thickness, weight, and length). The smaller sizes are less thick and allow the knife to move through flesh more easily and are much more nimble. They are still much thinner behind the edge and more fragile than a Western butcher knife. General size is 120 mm to 210 mm.
Usuba: (literally thin blade). Thinnest of the three general knife shapes. Flat edge profile. Used for push cutting, katsuramuki (rotary cutting thin sheets) and sengiri (cutting thin strips from those sheets). There is edo-usuba (square tip) and kamagata-usuba (round tip). General sizes are 180 mm to 240 mm.
Kiritsuke: hybrid with the length of yanagiba and the blade height and profile of usuba with an angled tip as a compromise. Requires great knife control because of the height, length, and flatness. General size is 240 mm to 300 mm.
Mukimono: Used along usuba for vegetables. It has an angled tip for decorative vegetable cutting. General size is 150 mm to 210 mm.
Hamokiri: (literally pike conger cutter). It is a knife intermediate in thickness and length between deba and yanagiba to cut the thin bones and flesh of pike conger. General size is 240 mm to 300 mm.
Magurokiri: (literally tuna knife). It is used to cut perpendicular (shorter) or parallel (longer and more flexible) to the tuna and is sized accordingly. Sizes range from 400 mm to 1500 mm.
Honesuki: Used to debone chicken. A thicker version is called garasuki is to cut through bones. Most have an angled tip to slip between tendons to cut them. General size is 135 mm to 180 mm.
Sobakiri: (literally soba cutter). A variant is udonkiri (udon cutter). General size is 210 mm to 300 mm.
Unagisaki: Eel knife. Comes in variants from Kanto, Kyoto, Nagoya, and Kyushu.

Steel

Defining characteristics of Japanese kitchen knives are toughness (resistance to breaking), sharpness (smallest carbide and grain for smallest apex reduce force in cutting), edge life (an index for the length of time an edge will cut based on lack of edge rolling or chipping), edge quality (toothy with large carbides or refined with small carbides), and ease of sharpening (steel easily abrades in stone and forms a sharp edge). Although each steel has its own chemical and structural limits and characteristics, the heat treatment and processing can bring out traits both inherent to the steel and like its opposite counterparts.

Stainless steel is generally tougher, less likely to chip, and less sharp than carbon. At the highest end, they retain an edge longer and are similarly sized in carbides to carbon steel. Variants include:

Powdered steel which has large carbides broken up by powdering process and sintered together under high pressure and temperature
Semi stainless which has a less chromium-free to prevent rust of the iron and intermediate properties between carbon and stainless
Tool steel which is heavily alloyed but may or may not is stainless.

Carbon steel is generally sharper, harder, more brittle, less tough, easier to sharpen, and more able to rust.

White steel: purified from phosphorus and sulfur and unalloyed. Comes in variants 1, 2, and 3 (from higher to lower carbon).
Blue steel: purified and alloyed with chromium and tungsten for edge life and toughness. Comes in variants 1, 2.
Super blue steel: blue steel alloyed with molybdenum and vanadium and more carbon for longer edge life but a little more brittle.

Construction

Monosteel blades are usually harder to sharpen and thinner than laminated blades.

Zenko (stamped out)
Honyaki (forged down from carbon steel and differentially hardened). Honyaki usually has higher sharpness and edge life than other forms of construction but are harder to sharpen. They are often thicker than other blades.
Forged down from a billet without differential hardening

Laminated blades called awase (mixed, for mixed steel), kasumi (misty, referring to the misty look of iron after sharpening), and Hon-kasumi (higher quality kasumi). Jigane refers to soft cladding or skin and hagane refers to hard cutting steel. Both commonly contain carbon or stainless steel, while constructions like stainless clad over a carbon core are less common due to difficulty. The jigane allows the knife to be much easier to sharpen and to absorb shock and allows the hagane to be made harder without making the whole blade fragile. This allows corrosion resistance and with the cutting powers of carbon. The two forms are:

Ni-mai (jigane with hagane)
San-mai (hagane sandwiched between jigane).

A variation is to form an artistic pattern in the jigane. Patterns include:

Suminagashi
Damascus
Kitaeji
Mokume-gane
Watetsu (when old Japanese iron is used)

Production

A great deal of high-quality Japanese cutlery originates from Sakai, the capital of samurai sword manufacturing since the 14th century. After the Meiji Restoration, the carrying of swords by the samurai class was banned as part of an attempt to modernize Japan. Though demand for military swords remained and some swordsmiths still produced traditional samurai swords as art, the majority of swordsmiths refocused their skill to cutlery production.

The production of steel knives in Sakai started in the 16th century when tobacco was introduced to Japan by the Portuguese, and Sakai craftsmen started to make knives for cutting tobacco. The Sakai knives industry received a major boost from the Tokugawa shogunate (1603–1868), which granted Sakai a special seal of approval and enhanced its reputation for quality (and according to some references a monopoly).

During the Edo period (1603–1867) (or more precisely the Genroku era (1688–1704)) the deba bocho were manufactured, soon followed by a wide range of other styles. Making kitchen knives and related products is still a major industry in Sakai, using a combination of modern machinery and traditional hand tools to make stain-resistant carbon steel blades.

Seki, Gifu is today considered the home of modern Japanese kitchen cutlery, where state-of-the-art manufacturing and technology has updated ancient forging skills to produce a world-class series of stainless and laminated steel kitchen knives famed throughout the world. The major cutlery making companies are based in Seki, and they produce the highest quality kitchen knives in the traditional Japanese style and the western style, like the gyuto and the santoku. Knives and swords are so much a part of the city that it is home of the Seki Cutlery Association, the Seki Swordsmith Museum, the Seki Outdoor Knife Show, the October Cutlery Festival, and the Cutlery Hall where tourists can purchase knives.

Another famous center for traditional blacksmiths and knifesmiths is Miki City. Miki is well known to all of Japan for its knife-making traditions, and its knives and tools recall the pride of Japanese steelmaking. Most Miki manufacturers are small family businesses where craftsmanship is more important than volume and typically produce fewer than a dozen knives a day.^[3]

The current knife centers of Japan include

Sakai, Osaka
Seki, Gifu
Sanjo
Tosa
Miki City
Tokyo
Tanegashima
Toyama

Design and use

Unlike western knives, Japanese knives are often single ground, i.e., sharpened so that only one side holds the cutting edge. As shown in the image, some Japanese knives are angled from both sides, and others are angled only from one side, with the other side of the blade being flat. It was originally believed that a blade angled only on one side cuts better and makes cleaner cuts, though requiring more skill in its use than a blade with a double-beveled edge. Usually, the right hand side of the blade is angled, as most people use the knife with their right hand, with ratios ranging from 70–30 for the average chef's knife, to 90–10 for professional sushi chef knives; left-handed models are rare and must be specially ordered and custom made.^[3]

Since the end of World War II, western-style double-beveled edged knives have become much more popular in Japan, the best example being that of the santoku, an adaptation of the gyuto (牛刀（ぎゅうとう）, gyūtō, gyuto, gyutou), the French chef's knife and the Sujihiki which is roughly analogous to a western slicing or carving knife. While these knives are usually sharpened symmetrically on both sides, their blades are still given Japanese-style acute-angle cutting edges of 8-10 degrees per side with a very hard temper to increase cutting ability.

Professional Japanese cooks usually own their personal set of knives, which are not used by other cooks. Some cooks may choose to own two sets of knives to alternate every other day. After sharpening a carbon-steel knife in the evening after use, the user may let the knife "rest" for a day to restore its patina and remove any metallic odour or taste that might otherwise be passed on to the food.^[4]

Japanese knives feature subtle variations on the chisel grind - the back side of the blade is often concave, to reduce drag and adhesion so the food separates more cleanly (this feature is known as urasuki^[5]). The kanisaki deba, used for cutting crab and other shellfish, has the grind on the opposite side (left side angled for right-handed use), so that the meat is not cut when chopping the shell.^[6]

References

^ Shackleford, Steve (2010-09-07). Spirit Of The Sword: A Celebration of Artistry and Craftsmanship. Krause Publications. ISBN 1440216398.
^ Carter, Murray (2011-09-22). Bladesmithing with Murray Carter: Modern Application of Traditional Techniques. Krause Publications. ISBN 1440218471.
^ ^a ^b Hurt, Harry, III (2006) "How to Succeed at Knife-Sharpening Without Losing a Thumb" The New York Times, September 23, 2006. Accessed September 23, 2006.
^ Shizuo Tsuji (1980). Japanese Cooking: A Simple Art. Kodansha International Limited. ISBN 978-0-87011-399-4.
^ Knife Edge Grind Types
^ Japanese Kitchen Knife Types And Styles

Tsuji, Shizuo, and Mary Sutherland. Japanese Cooking: A Simple Art, first edition. Tokyo: Kodansha International Ltd., 1980. ISBN 0-87011-399-2.