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The first time you take your Japanese knife to the whetstone to sharpen it can be an anxious moment, especially if you are unfamiliar with the geometry of Japanese knives. Patience, attention to detail, and some basic knowledge will get you sharpening your Japanese knife like a pro in no time!
Sharpening a Japanese knife like a pro requires using the right whetstones, the correct sharpening angle, the correct technique, and some patience. Double bevel knives are easier to sharpen since the geometry of single bevel knives requires different techniques for successful sharpening.
There is no disputing that it is possible to ruin a Japanese knife on a whetstone if you don’t know what you are doing. We have compiled the key factors and basic knowledge required to sharpen your Japanese knife successfully and establish a sharp, straight, and true edge on the blade!
If you are interested in checking out the best whetstones for your knives we recommend and use you can find them by clicking here (Amazon link).
Can Japanese Knives Be Sharpened?
Many people have heard that Japanese knives are made from extremely hard steel, making them impossible to sharpen. While it is true that Japanese steel is extremely hard, it is untrue that these knives cannot be sharpened.
There are also reports that Japanese knives are difficult to sharpen, and you should take your Japanese knife to a professional to get it sharpened. There is truth to the statement that Japanese knives are hard to sharpen, but it is a skill that can be learned with a little patience and care when you first begin.
Many people mistakenly think that because it is more difficult to sharpen a Japanese knife, it also takes a long time, and they will not have time for the task. It will take some time initially while you are learning the skill. However, once you are familiar with the sharpening process, it can take you anywhere from 5 to 15 minutes to sharpen a Japanese knife, depending on the amount of work the knife needs.
As with any new skill, some foundational skills and knowledge are needed to become proficient in sharpening a Japanese knife. We will cover the knowledge needed and walk you through the process of sharpening Japanese knives so you can approach the task with confidence.
What Is Your Current Knife Sharpening Experience?
If you have used a whetstone to sharpen other knives and have become competent with that task, you will have a head start on learning to sharpen Japanese knives.
You are at a disadvantage if you are on the other end of the scale and have never sharpened any knife on a whetstone. Having some experience will give you a feel for the stones, the angle of the blade, and the sharpening technique.
If you are new to whetstone sharpening, our suggestion would be to practice the basic skills we will discuss here by sharpening other knives in your collection before tackling your Japanese knives.
It is possible to ruin an expensive Japanese knife on a whetstone if you do not have experience with the correct sharpening process.
Do not be disheartened due to your lack of experience; it is worthwhile to persevere and improve your competence because knife sharpening can be satisfying and rewarding.
TIP: Buying genuine Japanese kitchen knives represents a significant investment when it comes to these kitchen tools. Check out the complete guide on how to care for Japanese knives in the article below:
How To Care For Japanese Knives: The Complete Guide
What Angle Are Japanese Knives Sharpened?
The most crucial element to get right with sharpening any knife is the angle on the bevel or cutting edge. Get this angle correct, and you will have an extremely sharp knife with a durable edge.
Getting the sharpening angle wrong or inconsistent during the sharpening process will dull the knife further and potentially damage the edge, requiring extensive work to repair the edge.
Japanese knives are sharpened to a more acute angle than western knives. The only reason this is possible is due to the hardness of the Japanese steel. A knife made from western steel honed to an edge as fine as a Japanese knife would become dull after the first few cuts because the metal is too soft to sustain the thin edge.
Most western kitchen knives are double bevel and are generally sharpened to an angle of 20° on the cutting edge. Traditionally, Japanese knives are single bevel, but double bevel knives were developed for the western market and are common in modern Japanese knives.
Japanese kitchen knives are sharpened to an angle of between 10° and 15°, which is extremely fine. Some Japanese knives are not sharpened to an edge as fine as this but are given a 17° angle on the cutting edge. If the knife is a double bevel, the angle would be the same on both sides of the knife.
Only one side of the edge is sharpened to a 10-15° angle on a single bevel knife. Single bevel knives are generally sharpened to a finer angle than double bevel knives. Many Japanese single bevel knives also have a concave grind on the flat side of the knife, making the knives complicated and difficult to sharpen.
Some Japanese knives have an offset bevel, where the angles are different on each side of the knife. These knives are very difficult to sharpen, and you should only attempt to sharpen a knife with this edge profile once you have some experience with knives with symmetrical bevels.
The documentation with your Japanese knife will generally indicate the bevel angles the knife edge should have, and you should maintain this recommended angle when sharpening your knives.
Are Japanese Knives Only Sharpened on One Side?
Traditionally, all Japanese knives were single bevel knives. As the knives became more popular in the western world, the Japanese knife manufacturers began creating and supplying double bevel knives to this new market.
Double bevel knives are easier to maintain and sharpen, and the western community is more familiar with this edge profile on their knives. Consequently, most Japanese knives can be double or single bevel, except for certain specialty knives, which are single bevel only.
If you have a double bevel Japanese knife, it must be sharpened on both sides. Many people may be surprised to discover that single bevel knives also require sharpening on both sides but using a different technique.
It would be best to select a double bevel Japanese knife when purchasing one of these knives because the edge is easier to maintain and sharpen.
TIP: Single bevel Japanese knives have benefits as well as some challenges, particularly in terms of the knife’s maintenance. Find out everything about single bevel Japanese knives in the article below:
Single Bevel Japanese Knife Types: Explanation & Usage
How Often Should You Sharpen A Japanese Knife?
Many people want a definitive answer about the frequency of knife sharpening to work the task into their schedule.
It is difficult to quantify the exact frequency of sharpening for your Japanese knife because it depends on how frequently you use the knife and how heavily you use it.
As a general rule-of-thumb, however, you should only sharpen your knives once every 4 weeks if you use the knives daily. Less frequent knife use will only require sharpening every 8 to 12 weeks as long as the knife is properly stored and maintained during this time.
There are steps you can implement to reduce the frequency of sharpening. Honing the knife before or after every use in the kitchen will extend the time interval between sharpening. Honing is not sharpening but rather touching up the edge of an already sharp knife to keep it in good condition and razor-sharp.
Honing on a Japanese knife can be done with a high grit whetstone, such as a 2000 to 6000 gritstone. A few passes over a high gritstone will restore the edge and limit the frequency of sharpening.
BTW: If you want to know more about Japanese and other types of knives and their sharpening check out the books listed above. These books are recommended by professional sharpeners and knife makers (Amazon links):
- Japanese Kitchen Knives: Essential Techniques and Recipes
- The Knifenerd Guide to Japanese Knives
- Knife: The Culture, Craft, and Cult of the Cook’s Knife
- Sharp: The Definitive Introduction to Knives, Sharpening, and Cutting Techniques, with Recipes from Great Chefs
Best Way To Sharpen Japanese Knife
As you may have surmised already, the best way to sharpen a Japanese knife is by using whetstones. To properly sharpen a Japanese knife, a series of whetstones ranging from coarse to ultra-fine grit is required.
Japanese steel is hard, making it necessary to have high-quality whetstones to cut the steel effectively and efficiently.
The hardness of the Japanese steel has a downside: the thin steel on the edge is brittle and cannot flex. This inflexibility of the steel means that certain sharpeners are inappropriate for Japanese knives.
Electric sharpeners, honing steel rods, and fixed angle sharpeners are generally unsuitable for sharpening Japanese knives.
Waterstones are the traditional method of sharpening these knives and are still the best method to get a great edge on the knives. Ceramic stones and diamond stones can also be used, but the Waterstones give the best feedback, particularly if you are new to sharpening knives.
TIP: If you are an owner of a set of Japanese knives, you would want to take the best care of them that you can. Can you use steel for sharpening Japanese knives? Find out more in the article below:
Complete Guide: Sharpening A Japanese Knife With Steel
How Do You Sharpen A Japanese Knife With A Whetstone
The sharpening process begins with choosing the right whetstone grits for the task. As a beginner, you should not use low grit, fixing stones below 400-grit, and attempt fixing a damaged edge, but rather stick to sharpening only.
You should start with medium grit stones for sharpening and work up to fine grit stones. As a guideline, we recommend the following stones for sharpening.
A 400-grit whetstone to establish the edge and a 1000-grit whetstone to refine the edge are the basic stones needed for the task. These two grits can often be purchased as a 400/1000-grit combo whetstone, which helps to save costs.
A 6000-grit finishing whetstone or polishing stone will be suitable as a polishing stone and a honing stone for regular maintenance.
Place your whetstone on a secure surface at a comfortable height to work so the whetstone will not slip or move around as you work.
TIP: Are you looking to buy a new whetstone? Check out our recommendations (we personally use the first three ones):
Our PRO choice whetstones combo (Amazon links):
- Fixing stone: Whetstone SHAPTON Ceramic KUROMAKU #320
- Sharpening stone: Suehiro CERAX soaking whetstone: Medium #1000
- Finishing stone: Whetstone SHAPTON Ceramic KUROMAKU #5000
Our budget choice (Amazon link): Sharp Pebble Extra Large Sharpening Stone Set
Establish The Sharpening Angle
Establishing the sharpening angle is the most crucial part of the process. How do you find the correct angle of the knife against the stone?
Most experienced people have developed an eye for the correct angle, but you need some guidance to find the correct angle as a beginner.
One of the best methods to find the right sharpening angle is to use angle guides such as the Wedgek Angle Guides (Amazon link) which offer angle guides in 1° increment from 10° to 20°. This makes them ideal for finding the correct sharpening angle for Japanese and western kitchen knives.
The wedges act as a visual reference to find the right angle. Place the appropriate angle guide on the stone and lay the knife on the guide with the sharp edge making contact with the stone’s surface.
Once you have a visual reference for the correct angle, remove the guide from under the knife, and you are ready to sharpen the knife.
TIP: Hard steel is brittle, so impacts or torsion on the edge can chip the blade’s cutting edge. Check out how to fix a chipped Japanese knife in the article below:
DIY: Fixing A Chipped Japanese Knife In 4 Simple Steps
Sharpen Your Japanese Knife
Start on the end of the whetstone furthest away from you. Position the knife on the stone with the edge facing away from you and the spine facing towards you.
Fine-tune the angle of the knife to the stone and draw the knife towards you across the stone, pulling the entire length of the blade across the stone at the same time in a single stroke.
Don’t push the sharp edge of the knife into the stone. The correct sharpening action is drawing the knife across the stone with the spine leading the way and the sharp edge following.
Be careful not to apply excessive pressure on the knife. Use the fingers of your non-dominant hand on the blade’s flat surface to apply a little pressure to the knife. This position helps stabilize the knife and maintain the correct angle throughout the stroke of the knife across the stone.
The pressure applied should only be slightly more than the knife’s weight resting on the stone. Do not be tempted to apply too much pressure to rush the process.
Perform 5 or 6 strokes of the blade on the same side across the whetstone. Then feel for a burr or a rough edge on the opposite edge of the knife that was in contact with the whetstone. The best way to check for a burr is to pull a fingernail down the side of the bevel toward the sharp edge. If you feel your nail hook on the edge, a burr has developed.
Feel for a burr along the entire length of the sharp edge. If the burr has developed across the entire length, turn the knife over and sharpen the other side.
You will start on the end of the stone closest to you on the second side, with the sharp edge facing you and the spine facing away from you. The stroke will be drawing the knife across the stone away from you, towards the far end of the stone.
Us the high gritstone to refine and polish the final edge on the knife. Honing is achieved by passing the knife across the stone for 3 to 5 strokes on each side of the blade. A burr is not developed during honing.
TIP: Whetstones can be an expensive investment for people starting out learning this sharpening technique which tempts them to buy cheap whetstones. But are cheap whetstones good enough? Find out the answer in the article below:
5 Reasons Why Expensive Whetstone Is Better Than Cheap One
How to Sharpen a Single Bevel Japanese Knife
Sharpening a single bevel knife is more difficult than sharpening a double bevel knife, and the technique is slightly different.
Start with the unbeveled side of the knife flat on the whetstone, with the knife at 90° to the stone. Keeping the knife flat, push the knife with the sharp edge facing away from you towards the far end of the stone. Do not apply pressure during this stroke where the edge is leading.
Once the knife has reached the end of the stone, pull the knife back towards you with the sharp edge trailing. On this part of the stroke, pressure is applied to the knife on the stone.
Do not spend too much time on one section of the knife, but work your way across the blade’s length on the stone. It only requires a few strokes to create a micro-burr on the opposite, beveled side of the knife.
Once the burr has developed, turn the knife over, so the beveled side is on the stone. On this side, the knife must not be flat on the stone but must be at the correct angle for the bevel. The knife can be held at a 45° angle to the stone than the 90° on the flat side.
The same backward and forward motion can be used to push and pull the knife over the stone, only applying pressure when the sharp edge is trailing.
Once you have completed a few minutes on each side of the knife, swop to a higher grit stone and repeat the process.
Finish with the highest gritstone to refine and polish the edge.
TIP: Most genuine Japanese knives are made with Japanese steel, which imparts certain characteristics to the blade. Check out all Japanese knife steels in the article below:
Japanese Knives Steel Types (Complete List with Explanation)
Sharpening Japanese knives is more difficult than sharpening other knives, but it is not impossible to learn this skill in a fairly short time.
Sharpening Japanese knives will develop your knife sharpening skills and increase your awareness of pressure, angles and bevels. Next time your Japanese knives need sharpening, consider spending the money on some good whetstones and learning to sharpen your Japanese knives like a pro!
TIP: Japanese knives are an expensive investment and are built with specific cutting tasks in mind. Find out what you can and can’t cut with Japanese knives in the article below:
Complete List: What NOT TO CUT With Japanese Knives & Why?