This blade slices, it dices

Top chefs adore them, Rachael Ray sells them, so what's the big fuss about Japanese knives?

By Harris Salat

Read more: Japan, Tokyo, Cooking, Life, Eat and Drink, Food and Travel

Feb. 1, 2008 | In the Quentin Tarantino movie "Kill Bill," Uma Thurman flies to Okinawa on a fateful mission: to find the greatest samurai blade ever forged. There she meets a white-robed master blacksmith who hands her a gleaming katana and solemnly intones, "I can tell you, with no ego, this is my finest sword."

Like Uma, I went on a quest for "Japanese steel." But my intentions were less homicidal: I needed it to chop shiitake, fillet tuna and julienne carrots. I'm a reporter by trade but am fascinated by Japanese food -- so much so that I volunteer a couple nights a week in the kitchen of a Japanese restaurant. The knives of the cooks all say the same thing: "Made in Japan."

And not just those of the cooks. Since the mid-'90s, Japanese knives have become de rigueur in professional kitchens of all stripes -- edging out, so to speak, German and French blades. As top chefs like Thomas Keller, Charlie Trotter and Jean-Georges Vongerichten discovered Japanese knives, home cooks began to follow, and in the last five years sales have exploded. Even the enterprising Rachael Ray now hawks an "East/West" blade based on Japanese design.

"They're perfectly engineered," said legendary four-star chef David Bouley. As he pulled out blade after Japanese blade -- he owns 50 -- he explained that these knives cut through the cells of ingredients so cleanly and precisely that food oxidizes more slowly, and tastes better as a result.

When I asked chef Eric Ripert, of New York's hallowed Le Bernardin, he got philosophical about his Japanese blades (all 25 of them): "When you own a Japanese knife, you show your commitment and passion for cooking," he said. "You're showing the other guys you're serious about what you do."

My own chef put it simply: "Get yourself some Japanese knives, man."

I decided to travel, à la Uma, to the source: a gritty industrial city called Sakai, 350 miles southwest of Tokyo. This old port has been the capital of samurai sword and knife manufacturing in Japan since the 1300s. A small band of artisans here still work in the traditional way, handcrafting blades in tiny workshops tucked between bland apartment buildings and factories.

A knife wholesaler named Junro Aoki offered to guide me, and we drove to a prefab warehouse that doubled as a smithy. Inside the soot-covered, dimly lit space a blacksmith stood in a cramped 2-foot-deep pit, face-to-flame with a coal-fueled forge breathing 1,400 degrees of blistering heat. He was 5 feet tall and wire thin, wearing a grimy turtleneck tucked into grey slacks, a denim shop apron and wooden flip-flops with purple socks. Prescription glasses framed his eyes. A cotton glove covered his right hand. That was it for protective gear. The fire from the forge cast an orange glow on his long face.

He didn't look up at us. With a pair of steel tongs, he shifted a white-hot steel bar from the forge to an anvil and began smacking it with a hammer. His head bobbed as he whacked the fiery metal only a couple of feet from his face. Sparks kicked up at him, but he didn't flinch. A knife -- a fish-slicing yanagi -- began to take shape from the bar. He tossed it on the dirt floor to cool.

Only then did he hop out of the pit to greet us. Up close I could see his clothes were peppered with tiny burn holes from the sparks. His name is Keijiro Doi. He's 80 years old and has been blacksmithing for six decades. He forges more than 100 different kinds of knives, shaping them by intuition and feel. "The fire and steel are both alive to me," he explained. His work is part craft, part art -- part sorcery. I asked him how he knows when a blade is ready.

"I can tell," he said.

By the time he finishes a knife, Doi has pounded it from a half-inch-thick steel bar down to a fifth-of-an-inch hardened carbon steel blade. He and his 52-year-old son, who helps him, finish about a dozen a day. The blades are dull gray in color, with no edge yet. The thin steel is incredibly strong. I tried to bend one I found in a junk pile. No dice.

This metal is key to understanding Japanese knives. Steel, of course, is an alloy of iron and carbon and other elements. Hardened steel -- the stuff of knives -- comes from heating, cooling and pounding steel until you crush together its molecules. Japanese carbon steel derives from techniques originally developed to produce steel for samurai swords. Its exceptional hardness lets you hone an incredibly sharp edge on the blade.

Shape is also critical. Japanese knives come in two broad styles: Western and traditional. Western looks like the double-edged knives we know. A gyutou is what we'd call a classic chef's knife -- this is the one American chefs typically buy. Traditional Japanese kitchen knives, on the other hand, come in three main shapes: yanagi, usuba and deba. The yanagi, which looks like a long willow leaf, is for slicing raw fish. The usuba has a wide rectangular blade for cutting vegetables. The deba is a heavy blade like a thick chef's knife, for portioning fish and chicken.

The Japanese endlessly riff on these three shapes. The local knife museum displays more than 160 different styles of knives, specialized blades to cut sea eel, freshwater eel (four distinct styles from four cities), whale, horse mackerel, the head of the bonito fish, Chinese cabbage, watermelon, silkworm, rolled sushi, soba noodles and 800-pound tunas -- this last one an astonishing 6-foot-long maguro kiri that looks like a sword. On top of this, the knives come in different sizes and combinations of steel. The museum alone sells 18 kinds of deba.

Traditional Japanese knives typically have one side sharpened, the other not, which lets you make precise, parchment-thin cuts.

Next page: If there's anything that puts a chef -- and his blades -- to the ultimate test, it's blowfish