With a swirly hammered surface and a single-edged blade that glides easily through fillets of fish, slabs of meat, and crisp vegetables, Japanese knives have become an essential tool in the hands of any chef or home cook. So what makes these knives so coveted in the kitchen, and are they really better than their European or American counterparts?
The hardness factor
There are two ways to make a Japanese knife: honyaki or kasumi. Honyaki uses only solid high-carbon steel, while kasumi forges a layer of hard steel with or between soft iron. The kasumi blade has a softer core, so is easier to sharpen. The blade is heated and hammered into shape by a master blacksmith, before being quenched in cool water to temper the material. This repetitive process, known as yaki-ire, creates a strong, durable blade. European blades are usually made with a softer steel, about 52–56 on the Rockwell scale (a scale used by metallurgists to define a piece of steel’s hardness), compared to 58–65 for Japanese knives. Nic Wong, head chef of Sydney’s modern Japanese restaurant Cho Cho San uses only Japanese knives both in his restaurant and at home. “Japanese steel is far superior. [The] design, style and efficiency are a step forward,” says Wong. “[Even] when I cook at home, which is usually something simple, clean and healthy, I use a good Japanese chef’s knife,” he says.
The right angle
The main difference between Japanese knives and their Western counterparts are their single-bevel edge. Only one side of a Japanese blade is sharpened to a wide angle of about 15 degrees compared to 20 degrees on most Western double-bevel knives. This thinner, one-sided blade is designed to slice much easier through food and deflect the cuts away from the blade as they’re sliced. Japanese chef Tetsuya Wakuda relies on the sharpness of Japanese knives to ensure a cleaner cut with his sushi and sashimi at his , the sharp cut ensures no damage is done to the surface or texture of the fish. “When you cut it, it feels different. The knife makes a very smooth cut, and it makes a big difference to the taste,” says Wakuda.
Get your hands on this salmon belly sashimi, pickled nori, daikon and carrot salad .
Salmon belly sashimi, pickled nori, daikon and carrot salad Source: Benito Martin
Light work
Blacksmiths in Japan hammer their blades until very thin, and design the shape to taper inside the handle. This lighter knife makes slicing and dicing much easier. While Western double-bevel knives enable a cook to cut food in a downward motion, Japanese knives, however, work best by draw-cutting – slicing the food toward you. For chefs who are cutting all day long, this is a less stressful movement. But such a delicate edge can be easily damaged if taking on the wrong task. “If you’re cutting something hard like meat with bones, Japanese knives won’t be suitable because the soft steel blade will easily break,” adds Wakuda. Tasks like butterflying a chicken, chopping frozen foods, or cutting through coconuts are best done with a cleaver or Western double-bevel chef’s knife.
Traditional talents
While factory-made Japanese knives exist and can be of high-quality, the best Japanese knives are made and sharpened by hand, crafted using traditional methods and tools since the production of samurai swords began more than 1000 years ago. The Japanese city of Sakai, in southern Kansai just next to Osaka, is known as the birthplace of traditional knives, with 90 per cent of Japanese chefs said to own a knife from Sakai. The city was also where Leigh Hudson, owner of Sydney’s Japanese knife shop and sharpening centre, , refined his skills as a knife-sharpener. “In my humble opinion [Sakai] is the most important knife-making district in Japan. [The knife-makers there] have a wealth of experience passed down through generations,” Hudson says. “I use a lot of Japanese knives made by knife-makers I’ve known for a decade. I find the knives have personality that in some ways reflect the personality of the maker.”
The perfect blade
When purchasing a Japanese knife, it’s important to know what you need it for. There are Japanese knives for every occasion, Wakuda uses a knife for filleting fish at Tetsuya’s, while long blades are perfect for thinly slicing sashimi. Hudson recommends a knife for beginners, a Japanese take on the double-bevel Western-style chefs’ knife that is the most versatile in the kitchen. A Japanese knife will need a lot of TLC, too. It’s important to sharpen the knives using a whetstone, and Hudson recommends doing it every day. But to make sure you get the angle perfect, it’s best to get them professionally sharpened regularly. While these knives require a little more love, when it comes to a sharper, lighter and more durable blade, hand-forged Japanese knives certainly make the cut.
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