Why Your Japanese Knife Won't Sharpen: An Expert Guide

Struggling to sharpen your Japanese knife? Let's tackle it with this guide! Discover why sharpening on a whetstone doesn’t restore your Japanese knife's edge, learn practical sharpening tips for beginners, and dive into advanced techniques for various types of knives—all presented in a fun and engaging way. 

We'll explore everything from 'How to Sharpen Different Types of Knives' to 'Understanding Knife Sharpening Techniques'. Plus, master the proper maintenance of your whetstone to sidestep common sharpening errors. 

Whether you're a professional chef or a home cooking enthusiast, transform how you use and care for your sharpening tools with this article. We'll even delve into the science of blade edges to demonstrate how different sharpening angles affect your knife’s performance.

 Let’s enhance our sharpening skills together and ensure your knives are always in prime condition!

Why Your Japanese Knife Won't Sharpen: Causes and Solutions

There are various reasons why you might struggle to sharpen your knife, but understanding these reasons can help you find solutions. 

Here, we'll discuss the main causes such as "not understanding the knife's shape," "lack of maintenance of the sharpening stone," and "insufficient sharpening time," and delve into each in detail.

Not Understanding the Knife's Shape

There are two main types of knives: "double-edged" and "single-edged," each requiring a different sharpening approach. If you sharpen without understanding the shape, the knife may not sharpen properly, leading to poor cutting performance.

Lack of Sharpening Stone Maintenance

Sharpening stones also require maintenance. They can become uneven with use, which can degrade the knife's sharpness. Regularly correcting the stone's surface is crucial.

Insufficient Sharpening Time

If you don't spend enough time sharpening your knife, the blade will not sharpen properly. Taking the time to carefully sharpen your knife will maintain its cutting effectiveness.

Now, let's explore these points in detail.

Understanding the Differences in Knife Shapes

Understanding the shape of your knife is the first step to correctly sharpening it. Knives are broadly categorized into "double-edged" and "single-edged," each with different characteristics and sharpening methods. Below, we'll explain the features of each type of knife and how to appropriately sharpen them.

Features of Double-Edged Knives

Double-Edged Knife (Front)	Double-Edged Knife (Back)

Double-edged knives are symmetrical in shape, commonly seen in Western knives like the general-purpose chef's knife and santoku. Both sides of a double-edged knife are sharpened at the same angle, making it symmetrical.

For this reason, it's necessary to evenly sharpen both sides of a double-edged knife. Care must be taken to evenly grind both cutting edges, which helps maintain the knife's sharpness and allows for smooth cutting of ingredients.

Characteristics of Single-Edged Knives

Single-Edged Knife (Front)	Single-Edged Knife (Back)

Single-edged knives have one flat side and another side that forms the blade, typical of Japanese knives like sashimi knives and deba knives. Single-edged knives are sharpened at a sharp angle on one side, while the other side is almost flat or slightly concave.

Therefore, a single-edged knife requires thorough sharpening on the bladed side, while the flat side should be minimally sharpened to maintain its slight concavity. This structure allows for an extremely sharp edge, enabling precise cutting tasks.

The Importance of Whetstone and Sharpening Stone Maintenance

Maintaining your sharpening stone is crucial for keeping your knife's edge sharp. Even if you're using the correct sharpening technique, a poorly maintained sharpening stone can quickly degrade the knife's sharpness. In this section, we'll explain how wear on the stone affects your knife and the importance of keeping the stone flat.

The Impact of Wear on Sharpening Stones

Sharpening stones wear down with use, gradually losing their flatness. This wear can result in uneven sharpening, rounding the knife's edge and deteriorating its sharpness. Particularly for those who frequently sharpen their knives, it's inevitable that the stone will wear down, necessitating regular maintenance.

Continuing to use a worn stone leads to unevenly sharpened knife edges, which can significantly reduce cutting efficiency and make it harder to re-sharpen the knife. Therefore, it's vital to regularly check the condition of the stone and adjust as needed.

How to Keep Your Sharpening Stone Flat

Maintaining the flatness of your sharpening stone typically involves using a lapping stone. A lapping stone helps to even out the surface of the sharpening stone, ensuring it remains flat and effective.

When using a lapping stone, soak the sharpening stone in water, then lightly press the lapping stone against it, moving evenly across the surface to grind it down uniformly.

Here are the steps for flattening your sharpening stone with a lapping stone:

1. Thoroughly soak the sharpening stone in water.
2. Place the lapping stone on the surface and gently move it back and forth.
3. Once the surface is flat, rinse the stone with water and let it dry.

By performing this maintenance regularly, you can keep the surface of your sharpening stone even, allowing for consistent sharpening of your knives. This, in turn, helps maintain your knife's sharpness for more efficient cooking.

Regular maintenance of your sharpening stone and timely adjustments ensure that you can always sharpen your knives optimally, thereby maximizing the performance of your knives.

How Long Should Knife Sharpening Take?

The time you spend sharpening your knife is crucial for maintaining its sharpness. Properly investing time in sharpening ensures that the knife's blade is well-maintained, enhancing your cooking efficiency. In this section, we'll explore the differences in sharpening time between professionals and amateurs, and discuss the sharpening methods for both double-edged and single-edged knives.

Differences in Sharpening Time Between Professionals and Amateurs

Professional chefs use their knives daily and sharpen them frequently, which means they can often do a quick sharpening in about 5 to 10 minutes. In contrast, in a typical household where knives are not sharpened as often, more time is needed to properly sharpen the knives.

If you only sharpen your knife once a month, the blade is likely to be quite dull, and it will require a significant amount of time to sharpen properly. Even for those experienced with knife sharpening, expect to spend at least 15 minutes, while those less experienced might need up to an hour. However, investing this time can dramatically improve the sharpness of your knife, making cooking easier and more enjoyable.

How to Sharpen Double-Edged Knives

Here we explain how to sharpen common types of double-edged knives, such as chef's knives and santoku knives. For practical demonstration, you might want to refer to this video tutorial, which provides step-by-step instructions: 

 Title: How to Sharpen a Gyuto Knife by a Professional Knife Maker

This video is a tutorial that demonstrates how to sharpen Gyuto knives and other double-beveled knives. By following along with the video, anyone can learn how to sharpen their knives effectively and with ease.

Materials Needed:

• Medium grit stone (No.1000)
• Finishing stone (No.6000)
• Stone Flattener
• Towel
• Stone holder (optional for convenience)

Steps:

1. Prepare the Stone: Soak the medium grit stone in water for 5-10 minutes. Flatten the stone's surface with a stone fixer, setting it up slightly tilted towards you (use a towel to create an angle if necessary).
2. Holding the Knife: Hold the knife by the handle with your middle, ring, and little fingers, place your index finger on the back of the knife, and your thumb near the base of the blade. As it's a double-edged knife, you'll sharpen the front side with your right hand and the back side with your left hand.
3. Sharpening Angle: Hold the knife at a 45-degree angle to the stone. Ensure the blade's bevel is fully in contact with the stone.
4. Sharpening Motion: Move the knife back and forth across the stone. Apply pressure when pushing forward and ease off when pulling back. Start at the base of the blade for stability.
5. Checking for a Burr: Continue sharpening until you feel a burr on the opposite side of the edge you're working on. Check by running your thumb parallel to the edge.
6. Sharpening the Back Side: Follow the same steps for the back side of the knife, holding it with your right hand and using your left to stabilize.
7. Using the Finishing Stone: Once done with the medium stone, repeat the process with the finishing stone, adjusting the angle slightly to around 15-20 degrees for final edge refinement.
8. Removing the Burr: Finally, remove any burrs by lightly stroking the blade with a rolled-up newspaper on both sides.

By following these steps and using the video tutorial as a guide, you can effectively maintain the sharpness of your double-edged knives.

Key Points for Sharpening Double-Edged Knives

Flattening the surface of your whetstone is crucial to prevent your knife from becoming warped. When sharpening, it's important to set the knife at a 45-degree angle against the stone, ensuring the bevel is firmly in contact. Use your right hand to hold the knife when sharpening the front side and switch to your left hand for the back side.

To ensure even sharpening on both sides, apply pressure when pushing the knife against the stone and ease off when pulling back. Sharpen the top, middle, and bottom sections of the knife equally, and continue until you can feel a burr forming along the edge. Finish by refining the edge on a finer grit stone and removing any burrs, achieving a beautifully sharp and finished blade.

How to Sharpen Single-Edged Knives

Here we explain how to sharpen a single-edged Deba knife. For a visual guide, please watch the accompanying tutorial video here: 

Title: How to Sharpen a Deba Knife by a Professional Knife Maker

This video is a tutorial that explains an easy method for sharpening a Deba knife, specifically designed for filleting fish. Even first-time users can sharpen their knives with confidence and avoid mistakes by following this guide.

 Materials Needed:

• Medium Grit Stone (No.1000)
• Finishing Stone (No.6000)
• Stone Flattener

Steps:

1. Preparing the Stone: Soak your medium grit stone in water until no bubbles emerge. Flatten the stone's surface using a stone flattener or a coarse stone to ensure safety by smoothing any sharp edges.
2. Holding the Knife: Grip the handle with your middle, ring, and little fingers. Place your index finger on the spine of the knife and your thumb near the base of the blade.
3. Knife Angle: Position the knife at a 45-degree angle to the stone, ensuring the beveled side is firmly against the stone.
4. Sharpening Motion: Start sharpening from the tip of the knife. Place your left hand on the backside of the knife and lift slightly with your right hand. Apply pressure on the forward stroke and release on the pullback.
5. Even Sharpening: Sharpen the top, middle, and bottom sections of the blade evenly, about 20 strokes each.
6. Checking for Burr: Check for a burr, a raised edge, on the opposite side to ensure the blade has been sharpened adequately. If areas without a burr are found, sharpen these spots again. Once a uniform burr is achieved, the medium stone sharpening is complete.
7. Finishing Stone Sharpening: Repeat the process with the finishing stone to refine the blade edge, adjusting your angle to 15-20 degrees for a finer edge.

Key Points for Sharpening Single-Edged Knives

 Ensure the stone surface is flat to prevent the knife from warping. When sharpening, it's crucial to apply pressure when pushing and lighten it when pulling back. 

For single-edged knives, avoid over-sharpening the flat side to prevent excessive thinning. Focus primarily on the beveled side, giving the flat side only a few passes. This method allows for efficient and effective sharpening of household Deba knives.

Essential Tips and Common Questions for Knife Sharpening Beginners

Sharpening knives might seem challenging for beginners, but grasping a few basic principles can make anyone proficient. Here, we discuss how the material of the knife affects its ease of sharpening, key tips for beginners, and answer some common questions.

How Knife Material Affects Ease of Sharpening

The material of the knife can significantly influence how easily it can be sharpened. Generally, carbon steel knives (Hagane) are easier to sharpen than stainless steel knives. Carbon steel is softer, allowing for a sharper edge in a shorter amount of time. In contrast, stainless steel knives take longer to sharpen but are more resistant to rust and easier to maintain.

Tips for Knife Sharpening Beginners

For beginners, it's crucial to:

• Maintain the Sharpening Angle: Keeping a consistent angle while sharpening is vital. A good guideline is about 15 degrees for double-edged knives and 10 degrees for single-edged knives.
• Apply Even Pressure: Ensure that the force applied is uniform across the knife while sharpening.
• Proper Sharpening Time: Take your time to sharpen thoroughly. Rushing might not adequately sharpen the knife, leaving it duller than expected.

Frequently Asked Questions About Knife Sharpening

Q:　What if there's no burr formation? 

A:　A burr, a metal sliver that forms when one side of the knife is sharpened, indicates where the knife has been sharpened. If no burr forms, it might suggest insufficient sharpening. Check if you're applying the correct angle and pressure.

Q:　Can you over-sharpen a knife? 

A:　Yes, over-sharpening can make the blade too thin and prone to chipping. If excessively worn, professional maintenance might be necessary.

Q:　Can stainless steel knives be sharpened?

A:　 While stainless steel knives are harder and take more time to sharpen, they can definitely be sharpened. The quality of stainless steel has improved significantly, and with proper techniques, these knives can also achieve excellent sharpness.

Q:　Are there knives that don't need sharpening? 

A:　No knife remains sharp forever without some sharpening. However, certain steels can maintain sharpness longer than others, reducing the frequency of sharpening needed.

Master the Art of Knife Sharpening and Enjoy Cooking More!

Understanding the type and material of your knife, along with proper sharpening and maintenance techniques, can dramatically improve its performance. By dedicating adequate time to sharpening and using the right methods, you can maximize the effectiveness of your knife.

Good maintenance not only ensures your knife is always ready for use but also enhances your cooking experience. Knowing how to properly maintain and sharpen your knives allows you to enjoy cooking more, making both the preparation and the meal itself more enjoyable.

To find the perfect knife that matches your needs and to further enhance your culinary adventures, visit Jikko Cutlery's website. Explore our wide range of high-quality knives and choose the best one to make your cooking even more enjoyable.

 Visit Jikko Cutlery.