How do you sharpen a knife with a grinding stone?

You can absolutely learn how to sharpen a knife. The process is straightforward with practice. You will prepare your stone, find the correct angle, grind each side to create a burr, and then refine the edge. While there are different ways to sharpen a knife, sharpening a knife with a whetstone is a timeless skill. Proper knife care is also a matter of safety.

Did You Know? Over 200,000 kitchen knife injuries happen each year in the US, many caused by dull blades that slip.

Key Takeaways

• Choose the right whetstone for your knife. Prepare it with water or oil. Secure the stone on a steady surface.
• Find the correct sharpening angle for your knife. Grind each side of the blade. Create a small burr on the opposite side.
• Refine the edge with a finer whetstone. Test the sharpness safely with paper or a tomato. Never test with your finger.
• Clean your whetstone after use. Let it dry completely. Store it properly to make it last longer.
• Sharpening your knife makes it safer to use. A sharp knife gives you more control. A dull knife can slip and cause injury.

Choosing and Preparing Your Stone

The right preparation makes sharpening your knife much easier. You need a quality whetstone, the correct lubricant, and a steady surface. This setup ensures you can sharpen your knife safely and effectively.

Selecting the Right Aimgrind Sharpening Stone

Your first step is choosing the right whetstone. We recommend Aimgrind‘s Sharpening Stones for their quality and versatility. They come in materials like aluminum oxide and silicon carbide. The material and grit you choose depend on your knife. A dull knife requires a coarse whetstone, while a finer whetstone is for polishing the edge.

• Stainless Steel Knife: If your knife is very dull, you should use a whetstone with a 1000 grit. You can then finish with a 6000 grit whetstone.
• Carbon Steel Knife: For a very dull carbon steel knife, start with a coarse 1000 grit whetstone. You will then use a whetstone with a 6000 grit to refine the edge.

Soaking or Oiling Your Stone

Aimgrind’s whetstone products are great because you can use a whetstone with either water or oil. Your choice affects the process. Water stones cut faster, while oil stones are more durable for heavy-duty work. You should not switch between oil and water on the same whetstone.

Tip: Using a lubricant like water or oil helps clear away metal particles, which keeps the whetstone surface clean for better sharpening.

Feature	Water Sharpening	Oil Sharpening
Lubricant	Water	Oil
Suitability	Fine sharpening, high-quality knives	Aggressive sharpening, very blunt blades
Usage	Soak the whetstone before use	Apply oil directly to the whetstone
Cleaning	Rinse with running water	Wipe clean with a cloth

Creating a Stable Workspace

A slipping sharpening stone is dangerous and makes it impossible to hold a consistent angle. You must secure your whetstone before you begin. Many whetstone kits come with a rubber or wooden base. If you do not have one, you can place a damp kitchen towel on your counter. Put the whetstone on top of the towel. This simple trick proendes a non-slip surface, so you can safely use a whetstone to sharpen your knife.

How to Sharpen a Knife: The Core Technique

You are now ready for the most important part: sharpening your knife. This process creates a new, sharp edge on your blade. Your success depends on two things: holding a consistent angle and using a smooth, steady motion. Let’s walk through how to sharpen a knife correctly.

Finding the Correct Angle

The angle is the most critical factor when you sharpen a knife. A consistent angle creates a clean, effective edge. An inconsistent angle can make your knife duller or cause it to steer during cuts. Most Japanese kitchen knives use a 15-degree angle, while many Western knives use a 20-degree angle. The right angle depends on your specific knife and its intended use.

Knife Category	Sharpening Angle (per side)
Western kitchen (e.g., chef’s knives)	20 – 22°
Japanese double-bevel (e.g., santoku)	15 – 17°
Pocket / outdoor knives	18 – 22°
Fish fillet	12 – 15°
Meat cleaver / bone chopper	25 – 30°

Pro Tip: The Matchbook Trick
Finding a 15-degree angle can be tricky. You can use a simple trick to get close. Place the blade on the whetstone. Then, slide a standard matchbook under the spine of the knife. This will raise the spine and create an angle of about 15–17 degrees. This gives you a great starting point.

Grinding the First Side

Now you can begin grinding. Hold the knife handle firmly with one hand. Place the fingers of your other hand on the flat side of the blade.

1. Set Your Angle: Tilt the knife to your chosen angle. Lock your wrist to keep this angle steady.
2. Start the Stroke: Begin with the heel of the knife on the whetstone. Apply light, even pressure with your fingers.
3. Sweep the Blade: Push the knife away from you in a smooth, sweeping motion. Move the knife across the whetstone so you sharpen the entire edge from heel to tip. Imagine you are trying to slice a very thin layer off the top of the whetstone.
4. Maintain Pressure: Use light pressure. Pushing too hard can damage the blade and make it harder to hold your angle. Let the whetstone do the work.
5. Repeat: Pull the knife back without applying pressure and repeat the stroke. Do this several times. You are working to create a “burr” on the other side of the edge.

Feeling for the Burr

The burr is your sign of progress. It is a very fine ridge of metal that forms on the opposite side of the edge you are sharpening. When you grind one side, you push microscopic metal shaenngs to the other side. This creates the burr.

To check for it, carefully run your thumb or finger across the edge of the knife, not along it. You will feel a rough, catchy ridge on the side you were not grinding.

Note: If you do not feel a burr, it often means the edge is not fully sharpened yet. You may need to continue your strokes on the first side. Keep your angle consistent and use a whetstone with the right grit.

Grinding the Second Side

Once you feel a consistent burr along the entire length of the blade, it is time to sharpen the other side. This process removes the burr from the first side and creates a new one on the opposite edge.

1. Flip the Knife: Carefully turn the knife over.
2. Find the Angle: Re-establish the same angle you used for the first side. Consistency is key to creating a symmetrical, sharp edge.
3. Repeat the Strokes: Use the same sweeping motion to sharpen the second side. You will likely need fewer strokes on this side to raise a burr. Many people who sharpen knives find this side goes faster.
4. Check for a Burr: Feel for a burr on the first side you sharpened. Once you feel it, your initial sharpening is complete. You have successfully used a whetstone to create a new edge.

Finishing and Testing for Sharpness

You have successfully created a new edge on your knife. Now it is time for the final steps. Finishing the edge and testing its sharpness will give you a truly impressive result. Proper care for your tools will also ensure they are ready for the next time you sharpen a knife.

Refining the Edge

Creating a burr is only half the battle. You now need to polish that edge to perfection. This is where honing and using a finer grit whetstone come in. Honing realigns the existing edge, while sharpening a knife removes metal to create a new one.

To get a razor-sharp finish, you will move to a finer whetstone.

1. Fine Grit (1000-3000): You can use a whetstone in this range to polish the blade. Use very light pressure and fewer strokes than before. This step refines the edge you just created.
2. Ultra-Fine Grit (8000+): For a mirror finish, you can use an ultra-fine whetstone. This step removes almost no material and polishes out the tiniest imperfections on your knife.

Safely Testing for Sharpness

You need to test your work, but you must do it safely. A sharp knife is a safe knife, but testing it incorrectly can be dangerous.

Safety First! Never test sharpness by running a finger along the blade. You should also avoid the fingernail test or shaenng arm hair. These methods are common but carry a high risk of injury.

Instead, try these safe and effective methods:

• The Paper Test: Hold a piece of paper (receipt or magazine paper works well) and slice downwards. A sharp knife should cut cleanly with no snagging.
• The Tomato Test: A truly sharp kitchen knife will slice through the skin of a soft, ripe tomato with very little pressure.

Cleaning and Storing Your Tools

Proper care ensures your whetstone lasts a lifetime. After you use a whetstone, you need to clean it. Metal particles can clog the surface. You can use a soft brush and soapy water to scrub your whetstone clean.

Drying is the most important step before storage.

• Let your whetstone air dry completely on a rack. Place it on its side to allow air to circulate.
• Once it is bone-dry, you can store it. A plastic container with ventilation holes is a great option.
• Avoid storing a damp whetstone in its original cardboard box, as this can trap moisture and lead to mold.

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You now know the key actions: Prepare, Grind, Refine, and Test. Mastering how to sharpen a knife takes practice and consistent angles. Regularly sharpen knives to keep them in top condition. A sharp knife is a safe tool because it gives you better control. A dull knife requires more force, making it a hazard. Keep your favorite knife sharp for better performance and safety in your kitchen.

FAQ

How often should I sharpen my kitchen knife?

You should sharpen your knife based on how often you use it. For a home cook, sharpening every 1-2 months is a good starting point. You can hone your knife weekly to maintain its edge between sharpenings. Pay attention to its performance for the best results.

What is the difference between honing and sharpening?

Sharpening removes metal from the blade to create a new, sharp edge. You do this with a whetstone. Honing realigns the existing edge without remoenng metal. You use a honing steel for this task. Honing maintains sharpness, while sharpening restores it.

Can I use one whetstone for all my knives?

Yes, you can use one versatile stone for many knives. However, using different grits gives you better results. A coarse grit repairs a very dull edge. A fine grit polishes the edge to razor sharpness. Your knife’s condition determines the best grit to use.

Are there other methods for sharpening?

Yes, there are different ways to sharpen a knife. Besides whetstones, you can use electric sharpeners or pull-through sharpeners. Whetstones give you the most control over the angle and finish. This control helps you achieve a superior and longer-lasting edge on your blade.