The Ultimate Guide to Sharpening Japanese Knives

Posted by Tara Hohenberger on

It’s important for knives to be sharpened periodically, because any knife will get dull over time. Repeated contact with the cutting board and friction from cutting through ingredients causes small damage that dulls a knife’s edge. Material has to be removed in order to restore the edge. Essentially, knife sharpening is effective because small amounts of metal are removed on either side of the edge creating a new sharper cutting surface.

Honing vs Sharpening 

Honing is that action you see a lot on cooking shows where the chef quickly runs the blade along a handheld honing rod - or honing steel. What honing is doing is re-aligning the edge, pushing any microscopic damage back into line. Dull knives that are honed, can feel like some sharpness is brought back, but it will never match the sharpness that you get from a whetstone.  That being said, in high speed environments like professional kitchens, there is not always time to sharpen a knife in the middle of a busy service.

Should you hone a Japanese knife? - It can be useful for professional chefs and home cooks that don’t have time to use sharpening stones, but ultimately a dull kitchen knife will need to be sharpened on a stone to bring back the cutting edge.

When You Should Sharpen Your Knives? 

It’s much better if you can sharpen your knives before the point where they are very dull. Frequency of sharpening will vary by knife and steel type, and depend a lot on how it’s being used and on what cutting board. Ideally, you will sharpen your kitchen knives as soon as you notice a decrease in performance.

How Long Does it Take to Sharpen a Knife?

Again it really depends on how dull the knife is, how hard the steel is and how much experience you have with knife sharpening. In general an edge can be restored within 10-20 minutes.

Can You Damage a Knife When Sharpening It?

Knives can be messed up, especially the blade road and edge alignment if you use the wrong technique.  The lower the grit, the rougher the stone and the more steel is removed. It’s easier to make mistakes with low grit sharpening stones.

The Different Types of Sharpeners and What You Should Use

Preferred Methods:  Waterstones — whether natural or synthetic a high quality Japanese whetstone is the top choice for sharpening Japanese knives.

What NOT to Use - We recommend avoiding pull-through and mechanical sharpeners.

Choosing the Right Grit - Depending on the condition of your knife, you’ll need to start with a lower grit option. #1000 medium grit is a good option for general maintenance, lower grit whetstones are useful for repairing damage such as chips and dings. Higher grit fine stones are a must for polishing edges.

Using Whetstones

What is a Whetstone? - Most commonly made from aluminum oxide, or silicon carbide ceramic, Synthetic water stones are softer than oil stones. Some need to be soaked and others splashed with water to help the knife’s edge move smoothly across the stone’s surface.

Dry vs Wet vs Oil Whetstones 

For Japanese knives, always use a whetstone. or waterstone.  Oil stones are harder and not recommended for Japanese cooking knives.  

How to Prep a Whetstone 

Soak the sharpening stone in water for 5-10 minutes.  Some finer sharpening stones (higher grit) can be used in the splash and go method.

How to Care for and Store Your Water Stone

It’s important to remove the stone from water and let it dry completely before boxing it.  It’s also recommended to flatten the stone periodically. The surface should be maintained so that there is no dip or divot in the surface.

Technique: How to Sharpen Japanese Knives

The key steps to sharpening knives involve running the blade edge along the stone until a burr forms on the opposite side. The knife is flipped over and the burr is removed, resulting in a new sharp edge

Single Bevel Knife Sharpening 

For traditional Japanese knives such as a yanagiba, deba or usuba. The sharpening angle should be around 15 degrees.

Double Bevel Knife Sharpening

For western style knives, such as santoku, gyuto and slicers. The blade angle will be identical on both sides for 50 /50 (typically an angle created by the height of two thin coins such as a penny). In the case of 70/30 angle blades, it’s 2 coins on the back side, and 3 coins on the cutting side (right for right-handed).

For help determining the sharpening angle and how to create and remove the burr please check out our essential sharpening series here.

How to Tell When a Knife is Sharp 

A sharpened knife will cut cleanly through a suspended piece of paper.

Using a Professional Sharpening Service

Why would you use a service? What should you look for? Using a service is a good option, especially if you find someone who can do a great job. It’s usually not cheap, but look for a sharpener who uses stones, not just wheels for knife sharpening. Look for recommendations and reviews to be sure the person is knowledgeable about Japanese knife sharpening.


You may remember being impressed with a brand new knife’s out of the box sharpness, but all well made knives have great potential and can return to top of the line performance after spending some time on a sharpening stone. There are many great sharpening resources available online. Check out our essential sharpening skills video and guide to choosing a sharpening stone. Shop our entire sharpening collection here.

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