How to Sharpen Japanese Knives for Sushi-Grade Slicing
When you are working in the kitchen, sharp knives can make all the difference between clean, accurate cuts and messy, hazardous slicing. A dull blade is actually more dangerous than a sharp blade because it's more likely to slide off the target, so it's essential to keep your knives sharp, especially if you spend a lot of time cooking and preparing food. You also shouldn't sharpen all knives in the same way. If you have Japanese knives, you'll need to use different methods to sharpen them than you use with Western knives. Here, use the this guide to learn how to sharpen Japanese knives and improve and maintain your cutting accuracy and control.
How Are Japanese Knives Different From Western Knives?
Japanese knives are characterized by harder, thinner steel. “When people say a Japanese knife, they generally mean a carbon steel blade with a one-sided edge. Western knives are generally stainless steel, have a double-sided edge, and are one piece with a full tang,” explains James Beard Award-winning chef Galen Zamarra, of Galen Zamarra Culinary Consulting.
Japanese knives may also have sharper edge angles of about 15 degrees, making them ideal for precise, delicate tasks like slicing fish or vegetables. Western knives use softer, tougher steel, with thicker blades and wider, double-bevel edges ranging from 20 to 25 degree angles, which are designed for heavy-duty tasks like chopping through bone or tough, dense foods.
Related: 5 Best Knife Sharpeners of 2025 for Beginners and Pros, Recommended by Experts
What Are the Best Sharpeners for Japanese Knives?
The best sharpeners for Japanese knives are high-quality, fine-grit combination whetstones with a 1000 grit for sharpening and a 5000 to 6000 grit for polishing. Chef Zamarra says, “I prefer a double-sided whetstone for either Western or Japanese knives. Whetstones use water for the lubricant. The 1000-grit side takes a dull knife to sharp pretty quick, and then it is finished on the 6000-grit side to really get it amazingly sharp. The 1000-grit will take a lot of metal off, so should not be used too often, especially on a carbon blade.”
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How to Sharpen Japanese Knives
- Place the knife at a 10 to 15 degree angle to the stone. For double-bevel knives, sharpen both sides equally. For single-bevel, focus primarily on the front side and a few light strokes on the back.
- Maintain a firm grip, placing your index and middle fingers near the edge, and push away with light pressure.
- Move back and forth in sections working through the heel, middle, and tip until a burr or a slight, rough edge can be felt on the opposite side of the edge.
- Once a burr is formed, switch to the other side of the blade and sharpen gently until the burr disappears, repeating until the edge is centered.
- Use a finer grit stone to polish, then strop the knife on leather or denim to remove microscopic burrs.
Related: How to Find the Correct Knife Sharpening Angle for Kitchen, Pocket, and Outdoor Knives
How to Avoid Common Mistakes When Sharpening Japanese Knives
Being aware of the most common mistakes people make when sharpening Japanese knives will help you to avoid them. Ideally, the best way to avoid common mistakes, like ruining the bevel angle, chipping the blade, or creating uneven edges, is to use the correct technique, equipment, and maintenance routines.
“Common mistakes include sharpening on too coarse a stone, which will wear down the blade quickly and unevenly, but also, it can create grooves in the stone which can chip the blade. Also not being consistent on the angle, which is really hard to gauge and takes time to master. Another mistake is to sharpen it properly on the stone, and then run it on a honing steel as if it is a double-sided blade,” notes chef Zamarra.
Related: How To Use a Honing Steel To Keep Your Knives Razor-Sharp
How to Tell If a Japanese Knife is Sharp or Dull
There are a few simple tests you can do to check if a Japanese knife is sharp or dull. A Japanese knife blade is typically considered sharp if it effortlessly slices a ripe tomato without significant pressure, bites into a fingernail when gently tapped at a 45-degree angle, or cuts through paper smoothly without tearing.
However, it is dull if the blade slides off a fingernail, squishes tomatoes instead of cutting, or tears paper crudely, rather than slicing. Additionally, chef Zamarra mentions that “you can inspect the blade visually and see how even and consistent the edge is, and when you cut something you will know how sharp it is.”