Published November 1, 2009. From Cook's Illustrated.
In Europe, the chef's knife is a sturdy tool that can chop and slice anything. In Japan it's a thin, light precision instrument. What happens when East meets West?
A good chef’s knife is the single most essential piece of kitchen equipment—at least in the European-American tradition. It serves as an all-purpose tool for cutting, slicing, mincing, and chopping everything from herbs to vegetables to meat. The Western chef’s knife is 8 to 10 inches long, with a pointed tip for precision work, a thick spine for strength to push through tough foods, and a curved edge that helps rhythmically rock the blade to chop a pile of carrots, dice an onion, or slice a cucumber. The cutting edge won’t easily chip or break and is simple to resharpen; it also works like a wedge, pushing food apart with a 20-degree angle to each side.
By contrast, in Japan, there is no such thing as one all-purpose chef’s knife. Since cutting technique is paramount in this cuisine—in some ways more important than actual cooking—Japanese chefs have always used at least three different knives. The yanagi has a long, slim blade for slicing raw, boneless fish. The deba is a thick-spined, heavy little knife for butchering meat and filleting fish. The usuba has a slim, rectangular blade for cutting vegetables.
Japanese chefs believe that cutting food without any crushing is essential to retaining its natural flavor. As a result, their knives (even the chunky deba) have extremely thin, sharp cutting edges honed on just one side to a 15-degree angle (see “East-West Blade Geometry,” above). To support this thinness, the knives must be made of very hard steel. The downside? Such blades are both more brittle and harder to resharpen than the softer steel of a Western-made knife. But brittleness is unimportant in a knife that is drawn along the board to slice (or held in the hands in a paring action), as opposed to pounded up and down, Western-style.
For centuries, these two culinary traditions have remained distinct. Now, top Japanese knife makers (including the famous “three Ms”: Masamoto, Masahiro, and Misono)—and even venerable German manufacturers Henckels and Messermeister—have merged East and West in an entirely new breed of knife. Called the gyutou (ghee-YOU-toe) in Japan, this hybrid tool fuses Japanese knifemaking (harder steel, a straighter edge for slicing rather than rocking, and slimmer, sharper 15-degree cutting angle) with Western knife design (the Western chef’s knife shape, and a blade sharpened on both sides). The result is feather-light, lethally sharp, wonderfully precise—and nothing like the heavy German-style knives many of us are accustomed to using. For me, taking up one of these knives for the first time was like removing heavy ski boots after a day on the slopes. You’re expecting a heaviness that’s no longer there.
But no matter how gloriously light, sharp, and deft these knives might be, would any work better than the traditional chef’s knife for the typical American home cook? To find out, we chose eight fusion knives, six by Japanese companies and two from European manufacturers, setting a price cap of $200. For comparison, we also tested our favorite inexpensive chef’s knife, the Victorinox Forschner Fibrox 8-Inch ($24.95). Since the Forschner is very inexpensive, this new style of knife would have to be pretty special to justify spending north of $100 to add it to our arsenal.
We chose testers of varying hand sizes and knife skills to perform a range of tasks in the test kitchen: dicing onion, mincing fresh parsley, cutting up a whole raw chicken, quartering butternut squash. Because how well a blade holds its edge is another critical part of the equation, we mailed off a set of the knives to Sheffield, England, where the Cutlery and Allied Trades Research Association (CATRA) machine-tested the durability of their sharpness. Finally, we chose the two knives that scored highest in our kitchen tests and sent them home with a couple of staff members to see how they held up in day-to-day cooking.
In test after test, the best knives stunned us with their ability to make precise, effortless slices. Taking apart a whole chicken at the joints and boning the breasts was a breeze with their narrow tips and maneuverable blades, and the rubbery skin practically opened up on its own. These precision instruments truly minced—rather than crushed—delicate herbs, leaving minuscule pieces of parsley unbruised, fluffy, and separate, rather than dark, oozing, and stuck together. For me, the difference stood out most when I cut through crisp onion. In contrast to clunky Western blades that tend to crush their way through the layers, my feeling of control—and the lack of irritating tears—was absolute as the thin, sharp blades glided through the onion with the barest pressure.
That said, not all of the knives were stellar performers. When mincing parsley, some test cooks found the straighter blades on a number of models took some getting used to. They missed the familiar curved blade of a Western knife, which encourages a rhythmic rocking motion, and favored any with a little more curve. Low handles on certain Japanese blades made larger-handed cooks’ knuckles strike the board as they worked. Some knives lost points for quirky design features, such as the metal handle on the slimmest, lightest knife in the lineup, which felt dangerously slippery to a few testers. Furthermore, while none failed at the task, some Japanese blades felt too delicate when confronted with hard, dense butternut squash.
Curiously, the two German hybrids were veritable flops. One was universally disliked by testers for its “heavy,” “clunky” feel and rated the poorest in edge retention—something corroborated by our testers, who actually noticed it dulling as they worked. While the other knife boasted a “beautiful” blade that was “sharp and fairly maneuverable,” its long-necked Japanese-style handle felt awkward, keeping testers’ hands too far from the blade. The only test where these two knives excelled was hacking through squash—a task that’s not very common, even in an American kitchen.
Conventional wisdom holds that the harder the steel, the longer a knife will stay sharp—an impression only fueled by knife companies bragging about the high “Rockwell hardness” of their blades, an industry scale where higher numbers indicate harder metal. But this supposed truism wasn’t borne out by our testing. We sent all of the knives in our lineup to the CATRA lab in England to evaluate durability. There, a machine sliced them through stacked sheets of sandpaper, then rated them according to how many sheets they cut before becoming dull. We compared these results to the Rockwell number for each blade—and found only a weak correlation. One knife, for example, did a far worse job of holding its edge than knives sharing the same Rockwell rating (or even those with a lower number, indicating softer metal).
It turns out that how well a blade’s edge will hold up is far more complicated than just its Rockwell rating. The properties of the blade depend on the exact steel alloy used to manufacture the knife (there are dozens of different types) as well as the makers’ secret formulas for heating, cooling, and hammering. Each of these factors affects the grain of the metal, the alignment of its molecules—and how long the knife will remain sharp.
In the end, we fell in love with two knives. Both weigh 6 ounces and had among the slimmest spines in our lineup, tapering dramatically to their cutting edges, giving them the narrowest profile for precision slicing. Cooks with a range of hand sizes and knife skills found each equally comfortable.
The interesting thing is, despite sharing what seemed to be a very similar blade design, each of these knives had a very distinct personality in the hand. Here’s why: Knifemakers can craft the way a blade feels and performs by making subtle changes in its blade geometry. For example, manufacturers can adjust the mass and balance of the blade not only by manipulating how much it tapers vertically from spine to cutting edge and horizontally from handle to tip, but where the horizontal taper begins—near the handle, midway down the knife, or even near the tip. One of our winners seems lighter and thinner because of a more extreme taper, both from handle to tip and vertically from spine to cutting edge. Testers who like German knives preferred our other winner for being stiffer and more solid. Scores were tied—until lab results revealed the final advantage: The steel of one knife was much better at staying sharp. (Another finding that disproved any notion that hardness alone helps a knife keep its edge.)