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HISTRY OF TRADITIONAL JAPANESE KNIVES

Kitchen knife is called “Hou-cho” in Japanese. The word originally came from China and means “a sword of Houtei”. “Houtei” is the name of the legendary Chinese cook existed more than 2000 years ago according to the Chinese old Taoist book “Zhuangzi”.

There is a legend that “Houtei” handled his knife skillfully and slaughtered thousands of cattle without breaking or chipping the blade, and even without sharpening it for decades.

With respect to “Houtei”, its name had somehow passed on for thousands of years and long way from China to Japan. But what interesting is, the word “Houtei” or ”Hou-cho” is not used in the present China, they are now only used by Japanese language.

Original Development of Japanese kitchen knives

Since the Stone Age, whether stone, steel or ceramics, knives have been indispensable tools for human beings.

The oldest kitchen knives found in Japan is from the Nara period (718-784 A.D.), which are now saved and kept in “Shosoin”, the treasure house belongs to the Todaiji Temple in Nara Prefecture.
They look like primitive Japanese swords. That type of knives was used until the beginning of 17th century, and they were then improved to modern type after that. Japanese knives such as “Deba” ”Yanagiba” and ”Nakiri” are the creations from this modern era.

In the mid-17th century, as soon as Japanese government lifted the foreign relations policy of locking the country, various goods and culture started coming into Japan. The western chef knives were brought in this period and quickly spread and accepted by Japanese people.
In the modern times, around mid 1900s, Japanese took advantages of western chef knife and traditional Japanese knife, and innovated “Santoku” knife. Santoku is now recognized worldwide.

Today Japanese kitchen knives are known as high quality, and also skillful technique behind that is well recognized. As a matter of fact, some Japanese knife manufacturers is producing the flagship models of the other well-known knife manufacturers in overseas.

BASIC CATEGORIES OF KNIVES

KASUMI-KNIVES

Kasumi are made from two (or more layers of) materials: “hagane” (hard brittle cutting steel) and soft iron “jigane” (protective steel) welded together. This style of knife offers a similar cutting edge to a honyaki blade. It also offers the benefit of being “more forgiving” and generally easier to maintain than the honyaki style, at the expense of the steels brittle nature.

HONGASUMI-KNIVES

Hongasumi knives are high-grade kasumi knives. They are often made of higher quality materials, paid special attention to and more steps are involved in the forging, tempering, and finishing processes.

DAMASCUS-KNIVES

Layered steel (Damascus steel) is becoming increasingly popular due to its added benefits and attractive appearance. To create these blades, high carbon steel is layered with soft iron then forged and hammered. Among the kasumi knives, layered steel blades have the longest edge retention.

White Steel (Shiro-ko)

Forging white steel is extremely difficult and required high skilled craftsmen. There are white steel #1, #2 and #3.   White steel #1 is the hardest steel among three.  A knife made in this steel has an extremely sharp edge but it is brittle and prone to chipping.

Blue Steel (Ao-gami, Blue-paper)

Blue Steel (Ao-gami, Blue-paper):  also a refined carbon steel with only a few impurities,
made by adding chrome and tungsten to white steel.  The addition of chrome and tungsten
increases wear resistance.  There are blue steel #1, #2 and super. It has great edge retention.

Blue Steel super (Ao-ko)

Blue Steel super (Ao-ko) is highest grade steel in their product line that contains high percentage of carbon, chrome to increese hardness, improviding edge retention and corrosion resistance.

About yasugi steel

The Japanese sword represents traditional Japanese craftsmanship. Made of Japanese steel using iron sand as the raw material, the edge of a Japanese sword is well known throughout the world. Hitachi Metals Co., Ltd., produces Yasugi steel from the raw materials for Japanese steel. In the past, iron sand with a high degree of purity could be excavated in the mountains in Tottori and Shimane prefectures and was refined to Tama Hagane using traditional processing (Tatara Processing). Hitachi Metals further improved the techniques, establishing their Yasugi Works to manufacture steel. The steel is called the blue steel, white steel, and yellow steel in the order of quality. Such names are said to be derived from the fact that blue and white papers were used to pack the finished steel for identification.

Styles and Uses of Traditional Japanese Knives

Yanagiba-knife
13-1
The Yanagi is a long slicing knife that was designed to slice thin slices of fish for sushi and sashimi. The length and shape of the blade allows it to slice through an ingredient in long uninterrupted strokes, preserving the ingredient’s freshness and integrity.
Deba knife
13-3
The Deba knife is a heavy knife that was made to filet and butcher whole fish. The heft of the Deba knife allows it to cut through the heads and bones of a fish, and its smaller pointed tip filets the flesh from the bones. The Deba knife can used be for chicken and meat but is not recommended for cutting through large bones.
Edo Usuba-knife (Kanto region style)
13-5
The blade is wider and thin, allowing cutting hard vegetables such as carrots without cracking them.
Usuba- knife kamagata style
13-4
Kamagata Usuba is a vegetable knife, originated in Kansai region. Small size is used for fine work such as decoration cutting.
Fugubiki-knife
13-7
The fugubiki is a traditional Japanese style blowfish slicer.
that the knife slices through fish better than the yanagi because of the extremely thin construction.
Takohiki-knife
18-3
The takohiki is a variation of the yanagi and is used to slice straight-cut sashimi. It’s thin body makes cutting thin slices of fish easier than the yanagi. The blunt tip and balanced weight works well on difficult ingredients such as octopus, from which it gets its name. Originated in Kanto (Tokyo) region.
Yanagi-kiritsuke / Slicer knife
kirituke
The Yanagi Kiritsuke knife is slightly heavier with a with a blade that is wider and a spine that is thicker.That can be used as either a sashimi knife or as an all-purpose knife. In sushi restaurant in Japan, this knife is traditionally used by the Executive Chef only and cannot be used by other cooks.
Gyuto-knife / chef knife
gyuto
The Gyuto knife is the Japanese equivalent of the Western chef knife. It is an all-purpose knife and can be used for cutting fish, meat and chopping vegetables.
Available steel: blue steel, white steel, V10, molybdenum, SK steel, etc.
Santoku-knife / multi purpose knife
santoku2
A Santoku knife is used to cut, slice, chop, and dice. It works well for slicing items such as fish, meat and chopping vegetables, The word Santoku translates as “3 good things” which means it is versatile like a chef’s knife and cuts vegetables, fish and meat.
Available steel: blue steel, white steel, V10, molybdenum, SK steel, etc.
Petty / utility knife
petty2
Petty knives are small utility knives of Japanese design.
The petty is makes it a convenient size for peeling and other delicate work.
Available steel: blue steel, white steel, V10, molybdenum, SK steel, etc.
Sujihiki-knife / Slicer knife
sujibiki
Sujihiki knives are the equivalent to a European slicer knife with a little bit differences. The blade is typically thinner and made out of harder steel, allowing for better edge retention. Sujihiki can be used for filleting,(sashimi) carving and general purposes.
Available steel: blue steel, white steel, V10, molybdenum, SK steel, etc.
Yo-deba knife / butcher knife
yodeba
Yo-deba knives are heavy, durable knives with a thick spine, which are used for fish and meat butchery. Also size varies depending on the size of the fish or animals.
Available steel: blue steel, white steel, V10, molybdenum, SK steel, etc.

"How to Sharpening your Knives"

Even knives of hight quality do not always ensure their real sharpness if not sharpened properly to their each use. In order to exercise their best performance,sharpening the edge to be strong and fine is essential.

Double-edged knives

Whetstones you should be using are #180 ~ 220 for Rough Sharpening, #600 ~ 1500 for Mid Sharpening, and #2200 ~ 5000 for Finishing.
First, using the whetstone for Rough Sharpening, sharpen the edge on both sides even by same angle. You adjust the total shape of the blade in this step. When the blade has some gristle, use the whetstone for Mid-Sharpening and repeat the process. When roughness on the edge lessons, stand the blade a little, and use less force holding the blade. Keep sharpening until smooth.
If you need fine edge, use the whetstone for finishing.When sharpening, if the angle of the edge on the whetstone is too obtuse, roughness can not be removed, and the edge becomes too thin so the blade can be easily chipped. The edge does not have the desired sharpness either. If the angle is too acute, the blade dose not slice well. The edge will not cut in smoothly even though the edge may be durable.Approximate angles and the proportion of the sharpening on the front to the back are described below.

Edge Angles
Thin knives such as Chef’s Knife, Paring knife should be sharpened by 8°~ 10°against the whetstone. Thick knives such as Boning Knife should be sharpened by 12°~ 15° Knives such as Chicken knife and Boning Knife should be sharpened 20°~ 30°for the front side and 2°~ 3°for the back side.

 

Proportion
Three – Seventh Sharpening —– Sharpen both sides at same angle at ration of 30% on the back and 70% on the front.
Double side sharpening —– Sharpen both side ratio.
One – Side Sharpening —– Sharpen mainly the front side but sharpen the back side slightly angled also.

Edge angle will vary by the knife types. Their purpose and the method of how the knife is used will determine the edge. If the edge is sharpened too flat, it becomes fragile and will not cut in smoothly. A curve edge is desirable.

Single-edged Knives

Whetstones you should be using are #180 ~ 220 for Rough Sharpening, #600 ~ 1500 for Mid Sharpening, and #2200 ~ 5000 for Finishing.
First, sharpen the section between SHINOGI and HASAKI (edge) on the front of the blade even: Rough Sharpening. You adjust the total shape of the blade in this step. When the blade has some gristle, next step is Mid-Sharpening. Use a finer whetstone and repeat the process. Sharpen the back of blade as well. For the back side, use a flat whetstone and sharpen from about 1 mm from the tip. When roughness on the edge lessons, stand the blade a little and use less force holding the blade. Keep sharpening until smooth. If you need finer edge, use the whetstone for finishing.
Single-side blade Japanese knives are slightly bowed on the back for easy sharpening. Make sure to sharpen remaining this shape. Sharpening too much on back will remove the shape. The range that should be sharpened on the back needs to increase up to 2 mm for knife using to slice tougher products.

Edge Angles
When sharpening, if the angle of the edge on the whetstone is too obtuse, roughness can not be removed, and the edge becomes too thin so the blade can be easily chipped. The edge does not have the desired sharpness either. If the angle is too acute, the blade does not slice well. The edge will not cut in smoothly even though the edge may be durable.
Edge angle will vary by the knife types. Their purpose and the method of how the knife is used will etermine the edge. A slight angled edge or a curved edge is desirable.