Bevels & Sharpness
Outside of balance, professional chefs know that proper edge angles and sharpness are paramount. It is often thought that a more narrow edge angle like 15 degrees would be sharper than a wider angle such as 30 degrees. In reality, a more narrow edge angle will have less resistance when passing through food products. It is this lessened amount of friction that gives the impression that it is sharper. Furthermore, with a more narrow edge angle, chefs will have better precision. Keep in mind that a more narrow edge angle will be more delicate. Conversely, a wider edge angle will have more strength. Edge retention and how often you sharpen a knife are relative questions. More accurately, let’s look at how the knife is being handled. Is the cutting surface hard plastic or soft wood? Is the knife being used more for soft food products rather than hard or dense items? What is the HR Rockwell hardness of the blade? Is the knife's edge being mistreated and scraped across the cutting board? Is the sharpening stone of good quality? Is the sharpening stone itself being cared for properly? Is the sharpening stone kept flat? Each of these points is important to the overall care and edge retention of your cutlery.
Understanding a double-bevel edge versus a single-bevel edge is pretty straight forward. A bevel is the surface that has been ground, forming the knife’s cutting edge. When looked at closely, you can see the angle on both sides of the blade or only one. If both sides have an edge, then it’s a double-bevel knife. If there is only one, then it’s a single-bevel blade. The bevel may be ground in a variety of angles.
Double-bevel knives, sometimes referred to as double-edge knives, have an edge/bevel ground on both sides of the blade. Typically, double-bevel kitchen cutlery has a 50:50 V-shape edge from 15 to 20 degrees, although up to 30 degrees is established on blades used for heavy chopping or meat cleaving. Less common edges can be established, such as compound bevels, asymmetrical-V-shapes or convex grinds. Double-bevel knives are more versatile and can be used by anyone at any level.
Single-Bevel knives originated out of Japan, and are produced in a wide range of shapes and sizes. Designed to perform specific tasks such as butchering fish, cutting vegetables, noodles, eel, etc. The list goes on and on. These Japanese knives are commonplace for professionals and Japanese kitchens, especially Sushi restaurants. This one-sided style of blade has the edge angle on the front with a slight convex shape on the back of the knife. This geometry allows for a much steeper taper that produces a very fine edge, usually 15 to 17 degrees. These precise blades cut delicate food products with ease. A single-bevel knife tends to deviate in the opposite direction of the hand holding it (it takes practice). Also, single-bevel knives are specific to right- or left-handedness.