Whetstone Sharpening: How To Sharpen Kitchen Knives With A Whetstone

Can I sharpen my kitchen knives with a whetstone? Yes, you absolutely can, and it is the best way to achieve a truly sharp edge on your blades. Whetstone sharpening is a time-honored skill. It gives you total control over the edge of your knife. This guide will show you how to use knife sharpening stones like a pro. We will cover everything from choosing the right stone to finishing with a mirror polish.

Grasping the Basics of Knife Sharpening

Before we start grinding metal, we need to know what we are doing. Sharpening is not the same as honing. Honing straightens a slightly rolled edge. Sharpening removes metal to create a new, sharp edge. For serious edge restoration or changing the edge angle, you must use wet sharpening stones.

Honing vs Sharpening: What Is the Difference?

Many home cooks confuse these two actions.

Action	Purpose	Tool Used	Frequency
Honing	Realignment of the edge	Honing Steel	Every use or every few uses
Sharpening	Metal removal and edge creation	Whetstones	When honing no longer works (infrequently)

When your knife feels dull, it usually needs sharpening. Honing will not fix a truly blunt knife.

Picking Your Whetstones: The Grit Guide

Whetstone technique relies heavily on using the right grits in the right order. Whetstones come in many types, but for kitchen use, water stones for knives are the most popular. They are easy to use and create very little dust.

Essential Grit Levels

Grit refers to how coarse the stone surface is. Higher numbers mean finer, smoother stones. You need a set, not just one stone, for a proper sharpening progression.

Coarse Grit Whetstone (120 to 800 Grit): This is for very dull, damaged, or completely reshaped edges. It removes metal fast. Use a coarse grit whetstone sparingly. It takes off a lot of material quickly.
Medium Grit Whetstone (1000 to 3000 Grit): This is the workhorse. The 1000 grit stone is the standard starting point for most maintenance sharpening. It smooths out the scratches left by the coarse stone.
Fine Grit Whetstone (4000 Grit and Higher): These stones refine the edge. They remove the scratches from the medium stone. A 6000 or 8000 grit stone creates a very sharp, polished edge.
Finishing/Polishing Stone (8000 Grit and Above): These stones create a razor-sharp, mirror-like finish, often favored in Japanese knife sharpening.

For general home use, a good three-stone setup is a 1000/3000/6000 combination stone.

Preparing Your Whetstones

Most modern water stones for knives need soaking before use. This is vital for performance and stone longevity.

Soaking the Stones

Place your whetstones in a tub of water.
Let them soak until they stop bubbling. This usually takes 5 to 15 minutes.
The stone must stay wet during the entire sharpening process. Add a little water frequently to keep the surface muddy. This mud (swarf) is a mix of water and fine metal particles. It helps with sharpening.

Some very hard stones are “splash-and-go.” These only need a quick splash of water on the surface before use. Always check the stone manufacturer’s instructions.

Setting Up Your Sharpening Station

A safe and stable setup prevents accidents and ensures consistent results.

Work Surface Needs

You must secure your stone firmly. A slipping stone is dangerous.

Use a specialized, non-slip rubber mat.
Place a damp towel underneath the stone base if you do not have a holder.
The stone should be flat on a sturdy table or counter. You need to work at a comfortable height.

Fathoming Sharpening Angles

The sharpening angles determine how aggressive or delicate your knife edge will be. This is the most crucial part of the technique.

Angle Basics

The angle is measured between the stone surface and the flat face of the knife blade.

Western/German Knives: Usually use a 20-degree angle per side. This means a 40-degree inclusive angle. These knives are sturdy.
Japanese Knives: Often use a sharper angle, between 10 and 15 degrees per side (20 to 30 degrees inclusive). These edges are sharper but can chip more easily.

Finding your angle is easier than it sounds. Use a small wedge or an angle guide clip when starting out.

Finding the Correct Angle By Sight

Place the knife flat on the stone (0 degrees).
Lift the spine until it is pointing straight up (90 degrees).
Halve that angle to 45 degrees.
Halve the 45-degree angle again to get 22.5 degrees. This is very close to 20 degrees.
For 15 degrees, aim slightly lower than halfway between flat and 45 degrees.

Practice finding the angle without the stone first. Keep your wrist locked. The angle must stay the same throughout the stroke.

The Sharpening Progression: Step-by-Step Guide

We start coarse and move toward fine grits. Never skip grits unless you are an expert trying to save time. Moving directly from a 400 grit to a 6000 grit stone will leave deep, sloppy scratches.

Phase 1: Establishing the Edge (Coarse Grit)

Use your coarse grit whetstone (e.g., 400 or 600 grit) if the knife is very dull or chipped. If the edge is only slightly dull, start with the 1000 grit stone.

Set the Angle: Place the knife edge on the stone at your chosen angle (e.g., 20 degrees).
The Stroke: Use light to moderate pressure. Push the knife across the stone, moving away from you. Make sure the entire length of the edge contacts the stone evenly.
- Some people prefer pulling the knife toward them. Choose one direction and stick with it. Consistency matters most.
Count Strokes: Do 10 to 15 strokes on one side.
Switch Sides: Flip the knife over. Repeat the exact same number of strokes on the second side.
Check for the Burr: The burr is the tiny piece of metal folded over to the opposite side during sharpening. You must raise a burr.

Detecting the Burr

Gently run your fingertip away from the edge on the side you are not sharpening. If you feel a slight, consistent roughness or wire edge along the entire length, you have raised the burr. If you don’t feel it, keep sharpening that side until you do.

Phase 2: Refining the Edge (Medium Grit)

Once the burr is established across the whole blade on the coarse stone, move to your medium stone (e.g., 1000 grit).

Maintain the Angle: Use the same angle you used on the coarse stone.
Reduce Pressure: Use much lighter pressure than you did on the coarse stone. The goal now is to remove the deep scratches left by the lower grit stone.
Stroke Count: Do 10 strokes per side.
Burr Check: Check for the burr again. If you don’t feel it, you haven’t fully refined the edge from the previous stone. If you raised a burr on the 1000 grit stone, you are ready for the next step.

Phase 3: Polishing and Finalizing (Fine Grit)

Now we move to the fine grit whetstone (e.g., 4000 or 6000 grit). This step creates the keen edge ready for slicing.

Very Light Pressure: Use almost no pressure—just the weight of the knife.
Alternating Strokes: The key here is to alternate sides frequently. This helps remove the burr cleanly.
- One stroke on Side A.
- One stroke on Side B.
- Repeat this sequence 10 to 20 times.
Stropping Motion (Optional): Some people use a final few alternating strokes where they slightly lift the spine of the knife away from the stone at the end of the stroke. This helps shear off the final bit of the burr.

Advanced Japanese Knife Sharpening Techniques

Japanese knife sharpening often involves lower angles and a commitment to high polish. Many Japanese blades are thinner and harder steel. They require a very delicate touch.

Establishing the Bevel

Traditional Japanese knife sharpening focuses on setting the primary bevel angle perfectly. Because these knives are often single bevel (like Yanagiba sushi knives), you only sharpen one side until the burr forms on the opposite side.

For double-bevel Japanese knives (Gyuto, Santoku), the process follows the progression above but often with a final polishing stone of 8000 grit or higher for a true razor finish.

Thinning the Blade (Scary Sharp)

If your knife cuts well but feels “thick” behind the edge, it might need thinning. This is a more advanced step done on the medium or fine stones. Instead of sharpening the very edge, you work slightly further up the blade face at a very shallow angle to remove bulk metal. Be very careful not to change the primary edge angle during this process.

Finishing Touches: Stropping

Stropping is the final critical step, even after using a high-grit stone. Stropping refines the edge further and removes any microscopic burr left behind.

Using a Leather Strop

A leather strop acts like an extremely fine finishing stone. You can use leather with polishing compound or plain leather.

Compound Application (Optional): If using a compound (like chromium oxide), apply a very thin layer to the leather.
Stropping Motion: Always pull the edge away from the cutting edge onto the strop (like shaving your face). Never push the edge into the leather, or you will cut it.
Strokes: Do 10 to 20 passes per side.
Check Sharpness: After stropping, test your edge.

Testing for Sharpness

How do you know when you are done? Sharpness testing should be done carefully.

The Paper Test: Hold a piece of thin paper (like receipt paper) in the air. A truly sharp knife should slice through it smoothly without tearing or catching.
The Tomato Test: A very sharp knife should bite into the skin of a ripe tomato with almost no downward pressure.

Maintaining Your Whetstones

Your stones do not stay flat forever. Heavy use wears down the center more than the edges. A hollowed-out stone leads to an uneven, poorly sharpened edge.

Flattening the Stones (Lapping)

Flattening ensures your sharpening angles remain true.

Use a Flattening Stone: This is a very coarse stone (like 120 grit or specialized flattening stone) designed only to wear down the softer sharpening stones.
Soak the Whetstone: Ensure the stone you are flattening is soaked.
Lapping: Place the flattening stone on your work surface. Add water. Rub the sharpening stone flat side down across the flattening stone using circular or sweeping motions.
Check Flatness: After a few minutes, rinse both stones. You can use a ruler placed across the stone’s surface. If there is a gap between the ruler and the stone center, it is hollow. Keep lapping until the ruler touches the entire surface.

Safety First: Essential Whetstone Sharpening Tips

Sharpening involves handling extremely sharp objects and abrasive materials. Safety is paramount.

Always keep your stones wet when in use.
Keep your fingers clear of the edge, especially when checking for the burr.
When sharpening, brace your non-dominant hand firmly on the spine of the knife to maintain control.
Clean your stones and tools thoroughly after every session.

Why Choose Whetstones Over Other Methods?

Many electric sharpeners and pull-through sharpeners exist. So, why master whetstone technique?

Control: You dictate the exact angle, grit progression, and pressure. This is vital for specialized knives.
Edge Quality: Whetstones produce a superior, less heat-damaged edge compared to many electric grinders.
Longevity: Whetstones, when properly maintained, last virtually forever. Electric sharpeners wear out their abrasive wheels.
Versatility: You can sharpen nearly any blade geometry (single bevel, recurves, gut hooks) on a flat stone surface.

Frequently Asked Questions (FAQ) About Whetstone Sharpening

Q: How often do I need to sharpen my kitchen knives?

A: This depends on use. A home cook might sharpen every 3 to 6 months. Professional chefs might sharpen every few weeks, but they will hone much more often. If honing no longer restores the edge, it is time to sharpen.

Q: Can I use my whetstones dry?

A: Generally, no, especially for standard water stones for knives. Dry use creates excessive dust, wears the stone down very quickly, and generates more heat, which can ruin the temper of the knife steel. Always keep the stone surface wet.

Q: My knife has a very aggressive V-shape. Can I change the sharpening angle?

A: Yes, you can change the angle, but you must use a coarse grit whetstone first. You need to remove enough metal from the existing bevel to create a new one at your desired angle (e.g., moving from 22 degrees down to 15 degrees). This takes significant time and material removal.

Q: Is the mud (swarf) on the stone good or bad?

A: The mud is good! It is metal fines mixed with stone particles. This slurry actually helps the sharpening process on medium and fine stones by providing an extra layer of micro-abrasives. Do not wipe it all off immediately; just add more water if it dries out.

Q: Do I need special stones for stainless steel versus carbon steel?

A: While the steel types require different care (carbon steel rusts easily if left wet), the stones themselves can usually handle both. High-quality wet sharpening stones work well on both types of kitchen knives. Carbon steel often polishes to a higher shine faster.