【Reading】りょうば

【English Name】Double-edged blade

Ryoba (double-edged) refers to the blade structure in which both the left and right faces of the cutting edge are ground out into a V shape. Its antonym is "kataba" (single-edged), in which only one side is given a cutting edge.

In knives, many Western-style knives adopt this double-edged structure. Because the blade is formed symmetrically on the left and right, it can be used regardless of one's dominant hand, and it is characterized as cutting straight ahead in the direction the food is pushed. A single knife can handle a wide range of ingredients—meat, vegetables, fish—and the design emphasizes versatility and robustness.

On the other hand, many traditional Japanese knives have a single-edged structure, and they are said to enable delicate cutting that takes advantage of the thinness of the cutting edge. In the world of sushi, single-edged yanagiba and deba knives are valued for finishing a beautiful cut surface without crushing the cells of the ingredient. They are said to deliver a sharper cutting edge compared to double-edged knives, and it is said that the difference in culinary philosophy—"Western cuisine is addition, Japanese cuisine is subtraction"—is reflected even in the structure of the knives.

In recent years, Japanese-Western hybrid types with a double-edged structure, such as the santoku knife, have also become widespread and are widely beloved for home use. When sharpening, both faces must be sharpened evenly, which is a major difference in maintenance from single-edged knives.