Simple Steps: How To Sharpen A Kitchen Knife With A Whetstone

What is a whetstone? A whetstone is a block of abrasive material used to sharpen tools, especially knives, by grinding away small amounts of metal from the edge. Can I use a whetstone on any knife? Yes, whetstones are excellent for sharpening most kitchen knives, including German, Japanese, and stainless steel blades.

Achieving a truly sharp kitchen knife is not hard. Many chefs swear by whetstone knife sharpening. It gives you the best results. You get a very fine, long-lasting edge. This guide will show you how. We will break down the steps simply. You will soon master using a whetstone on knives.

Why Choose a Whetstone?

Before diving into the steps, let’s look at why a whetstone is the top choice for sharp edges. Many people use pull-through sharpeners. These can work fast, but they remove too much metal too quickly. They often ruin the knife’s edge angle over time.

Whetstones offer control. They let you work with the original angle of your knife. This keeps your good knives lasting much longer.

Honing vs. Sharpening a Knife

It is key to know the difference between honing vs sharpening a knife. They are not the same job.

Honing: This straightens the rolled edge of a knife. Think of it like brushing your hair back into place. It uses a honing steel. It does not remove metal. Do this often, maybe every few uses.
Sharpening: This removes metal to create a brand-new, sharp edge. This is what you do with a whetstone. You only need to sharpen a knife a few times a year.

Picking Your Tools: The Right Whetstone Setup

To start, you need the right gear. Your main tool is the whetstone itself.

Water vs Oil Whetstone

There are two main types of sharpening stones: water vs oil whetstone systems. Both work well. They just need different care.

Stone Type	Lubricant Used	Cleaning After Use	Common Grit Range
Water Stones	Water	Rinse off slurry, dry completely.	Very wide range, common for home use.
Oil Stones	Honing Oil	Wipe oil off, must be stored dry.	Often harder, slower cutting, good for very hard steel.

Water stones are the most common choice for kitchen knives today. They clean up easily. They cut metal quickly when they are wet. Oil stones take longer to clean. They can be messy. For home cooks, water stones are often simpler.

Grits: The Coarse to Fine Whetstone Progression

Whetstones are rated by grit size. Grit refers to how rough the stone’s surface is. A low number means a coarse, rough stone. A high number means a fine, smooth stone. You must follow a coarse to fine whetstone progression for a perfect edge.

You usually need at least two stones, but three is better:

Coarse Grit (200 – 800): Use this for very dull knives, fixing chips, or setting a new edge angle.
Medium Grit (1000 – 2000): This is your main sharpening stone. It refines the edge made by the coarse stone. Most sharpening ends here.
Fine Grit (3000 – 8000+): This polishes the edge. It makes the knife razor sharp and smooth.

Step 1: Preparing Your Whetstone

New stones often need work before they can sharpen well.

Flattening a Whetstone

Over time, stones wear down unevenly. One side might dip in the middle. This ruins your edge angle. You must check and fix this regularly. This process is called flattening a whetstone.

You can use a special flattening stone (a lapping plate). Or, you can use coarse wet/dry sandpaper taped onto a flat surface, like a piece of glass.

Wet your flattening surface or the sandpaper.
Place your whetstone grit-side down on the surface.
Push the stone back and forth using light, even pressure. Keep the stone wet.
Check the stone often. Keep going until the entire surface is flat. You will see the high spots removed.

Soaking the Stone (Water Stones Only)

If you use water stones, they need to soak.

Place the stone in a container of clean water.
Let it soak until it stops bubbling. This usually takes 5 to 15 minutes.
A soaking stone is ready. Keep a small bowl of water nearby to splash the stone during sharpening.

Step 2: Finding the Right Angle

This is the most crucial part of whetstone knife sharpening. The angle dictates how sharp and how long the edge lasts. You must match the angle the knife was originally made with.

What is the Best Angle for Whetstone Sharpening?

The best angle for whetstone sharpening depends on the knife type and steel hardness.

Western/German Knives (High Durability): These usually use a 20-degree angle per side. This means a 40-degree total angle (20 degrees on the left, 20 degrees on the right). This angle is durable for tough cutting.
Japanese Knives (High Sharpness): These often use a sharper 10 to 15-degree angle per side (20 to 30 degrees total). This gives a finer, sharper edge but is more delicate.

Setting the Angle

If you are unsure of your knife’s angle, start with 20 degrees.

Place the knife blade flat on the stone (0 degrees).
Raise the spine of the knife until the edge just touches the stone. This is the 0-degree point.
Lift the spine up until you reach the desired angle. A common way to estimate 20 degrees is to lift the spine about the height of a US dime coin off the stone surface when the heel of the blade is on the stone.

Sharpening different knife angles may require practice. Try practicing on scrap metal or just using your fingers to feel the angle before putting the blade to the stone.

Step 3: The Sharpening Process – Medium Grit (1000)

Start with your medium stone (around 1000 grit). This is where you do most of the work. Make sure the stone is wet if you are using a water stone.

The Basic Motion: Proper Whetstone Technique

Proper whetstone technique involves pushing and pulling the blade across the stone. You must keep the same angle through the whole stroke.

Positioning: Place the stone firmly on a non-slip mat or damp towel. Hold the stone steady with your non-dominant hand.
Blade Placement: Place the heel of the blade on the stone, set at your chosen angle (e.g., 20 degrees).
The Push Stroke (Away from You): Apply light, even pressure. Push the knife away from your body, moving the blade across the stone. Think of trying to shave a very thin layer off the stone. The movement should go from the heel to the tip of the knife.
The Pull Stroke (Toward You): Flip the blade over (still at the same angle). Pull the blade toward your body. This stroke should be lighter than the push stroke.
Consistency is Key: Use smooth, steady strokes. Work the entire length of the blade, from the heel to the tip, in each pass.

Building the Burr

Your goal on the medium stone is to create a “burr.” A burr is a tiny, wire-like lip of metal that folds over to the opposite side of the edge you are sharpening.

Work one side of the knife until you feel the burr form along the entire length of the opposite edge.
To check for a burr, gently run your thumb away from the edge on the side you haven’t sharpened yet. If you feel a slight catch or snag, you have raised a burr.
Once you feel the burr along the whole edge, switch sides and sharpen the other side until you raise a burr there, too.

Step 4: Refining the Edge – Coarse to Fine Progression

Once you have a consistent burr on both sides using the 1000 grit stone, it is time to move up.

Using the Coarse Stone (If Needed)

If your knife was very dull or chipped, go back to your coarse stone (e.g., 400 grit). Repeat the sharpening motion until you form a burr again. This removes the deeper scratches left by the medium stone. Then, return to the medium stone to refine that new edge.

Moving to the Fine Stone (Polishing)

Switch to your fine grit stone (e.g., 4000 or 6000 grit). Keep the stone wet.

Repeat the same sharpening strokes. The goal here is not to create a burr, but to polish away the scratches left by the previous stone.
Use lighter pressure than you used on the 1000 grit stone.
Do about 10 strokes per side.

Removing the Burr (Stropping/Alternating Strokes)

Now you need to remove the final, microscopic burr. This is done by alternating sides with very light pressure.

Go back to your 1000 grit stone.
Do one light stroke on Side A.
Do one light stroke on Side B.
Repeat this alternating pattern (1-and-1), slowly reducing pressure each time. This action breaks off the final burr.
Finish with 5 alternating strokes on your finest stone (e.g., 6000 grit). Use almost no pressure on these final passes.

Step 5: Stropping for the Final Edge

Stropping is the final polish. It refines the edge further and removes any remaining microscopic inconsistencies. You can use a leather strop, or if you don’t have one, you can use the finest stone (like an 8000 grit stone) with almost no pressure, using only the pulling stroke direction (as if you are trying to remove the stone material, not the steel).

When stropping, you only use the pull stroke (or backstroke on a stone). You never push the edge into the strop or stone. This will damage your edge instantly.

Advanced Topics in Whetstone Sharpening

Sharpening Different Knife Angles

When sharpening different knife angles—like a fillet knife versus a cleaver—the process is the same, but the angle changes.

Fillet Knives (Flexible): Often need a very acute (shallow) angle, maybe 15 degrees, for maximum slicing.
Cleavers/Machetes (Heavy Chopping): Need a wider, more robust angle, sometimes 22-25 degrees, for strength against hard impacts.

If you own many knives, you might want angle guides that clip onto the spine. These are small plastic or metal wedges that help you maintain the exact angle while you are learning.

Maintaining a Sharp Kitchen Knife

Sharpening is only part of the job. Maintaining a sharp kitchen knife ensures your hard work lasts.

Hone Regularly: Use your honing steel often. This resets the edge between full sharpenings.
Use the Right Surface: Never cut on glass, ceramic, or metal countertops. Use wood, plastic, or bamboo boards.
Clean Properly: Wash knives by hand immediately after use. Never put them in the dishwasher. The harsh soap and tumbling dull the edge fast.
Proper Storage: Store knives in a block, on a magnetic strip, or in a sheath. Don’t let them rattle around loose in a drawer.

Troubleshooting Common Whetstone Issues

Even with the best instructions, things can go wrong. Here are common problems and quick fixes.

Problem 1: I can’t feel a burr.

Cause: You are likely not using enough pressure, or your angle is too high.

Fix: Go back to your medium stone. Increase pressure slightly. Make sure you are maintaining the exact same angle through the entire stroke. Try to make the burr heavier by doing 20 aggressive strokes on one side, then check for the catch.

Problem 2: The edge feels rough after using the fine stone.

Cause: You skipped grits or you didn’t fully remove the scratches from the previous, coarser stone.

Fix: Go back to the 1000 grit stone. Work that side again, focusing on refining the edge until the burr is light and thin. Then move back to the fine stone, but spend more time there alternating strokes to break off the burr cleanly.

Problem 3: My stone is glazed over and not cutting.

Cause: This often happens when using oil stones without enough oil, or when using water stones without enough water, or if you are sharpening soft steel. The metal particles clog the pores of the stone.

Fix: For water stones, scrub the surface with a bit of water and a soft brush to remove the metal paste (slurry). For oil stones, use mineral spirits or a proper stone cleaner to cut through the oil and clear the pores. If the stone is severely glazed, you may need to flatten it again.

Conclusion

Mastering whetstone knife sharpening takes practice. But once you get the feel for the correct angle and the proper whetstone technique, you will create edges that outperform any factory grind. Remember the coarse to fine whetstone progression. Take care of your stones by flattening a whetstone when needed. With regular honing vs sharpening a knife awareness, your kitchen tools will stay sharp for years.

Frequently Asked Questions (FAQ)

Q: How often should I sharpen my knives with a whetstone?
A: For most home cooks, sharpening every 3 to 6 months is enough, provided you hone regularly. If you use your knives heavily every day, you might need to sharpen every month or two.

Q: Can I use tap water on my whetstone?
A: Yes, for water stones, tap water is perfectly fine as the lubricant. Just be sure to rinse the slurry off after you finish.

Q: Should I sharpen both sides of the blade equally?
A: Yes, in almost all cases. Unless your knife is specifically designed for single-sided sharpening (like some very traditional Japanese single-bevel knives), you must sharpen both sides equally to maintain the center line of the blade.

Q: What do I do if I accidentally go too far into the knife metal and ruin the original angle?
A: This is why flattening a whetstone is important. If you realize your angle is off, go back to your coarse stone. Work only the edge that is too steep until you raise a burr on the other side. Then, resume your normal progression. You are basically resetting the edge.