Sharpening class. Learn the trade.

Sharpening with a Whetstone

Japanese knives are most effectively sharpened using whetstones. When sharpening on stones, the edge is not unnecessarily worn down, and you never need to send your knife away for professional resharpening. One major advantage of whetstones is that they naturally thin the edge as it migrates upward on the blade over time. This prevents the knife from developing a thick, wedge-like profile that causes a crushing or cracking sensation when cutting through ingredients like potatoes.

Sharpening on stones is not trivial. It requires commitment, patience, and the right equipment. That said, the learning curve is surprisingly short, and as with most skills, practice makes perfect.

If you want to truly fast-track your sharpening journey, we warmly recommend our sharpening courses in Bromma, Sweden. These stone-sharpening courses have become extremely popular and are often described as a quick and accessible way to learn proper technique from the ground up. No prior experience is required, and we guarantee that you will leave the course with both a razor-sharp knife and solid, hands-on knowledge of knife sharpening.

Getting Started on Your Own

Sharpening your own kitchen knives is both fun and deeply rewarding. The feeling when a knife glides effortlessly through a tomato, without turning it into a wet mess, is hard to beat. The only thing better is knowing that you created that edge yourself. In our opinion, knife sharpening is one of the more enjoyable and useful hobbies you can take up.

But where do you begin? What do you need? And what really matters? Our advice is to make sure you have the following:

Curiosity. If you’re reading this, you’re already there.
A bit of patience. Like anything worthwhile, sharpening takes time to master. You will hit plateaus along the way, but don’t get discouraged. Follow a few simple principles and you can achieve a razor-sharp edge even on your first attempt.
A coarse diamond stone, around 150 grit, For heavily worn knives and for flattening stones.
A medium whetstone, around 1000–2000 grit, For everyday sharpening.
A flat, fine whetstone, around 3000–4000 grit, For polishing the edge (optional if a purely functional edge is sufficient).
A stone holder is convenient, but not strictly necessary.

The Basics of Knife Sharpening

At its core, sharpening is about creating a sharp edge by removing steel in a controlled way. If we look at the knife edge in cross-section, it resembles the letter V. The very tip of that V is the cutting edge. Sharpening means removing material from the sides of the V until that point is formed.

Coarse stones remove steel quickly but leave deep scratches. Finer stones remove less material and refine the edge by smoothing those scratches. The general rule is to start with the coarsest stone necessary to shape the edge, then progress to finer stones to refine it.

Your First Sharpening Session

If the edge has visible or noticeable chips, or is extremely dull, start with the coarsest stone. If the knife is reasonably sharp and undamaged, begin with the medium stone.

To shape the edge, draw the knife back and forth across the wet stone at a consistent angle using light, steady pressure. Imagine that you are sliding one side of the V-shape along the surface of the stone. For a first sharpening, aim for an angle of approximately 10–15 degrees. A simple reference: place the blade flat on the stone, edge facing you, then raise the spine until you can just fit your little finger underneath it.

To maintain even pressure, place the fingers of your free hand lightly on the blade near the edge. You do not need much force. Keep the stone wet and repeat the motion steadily. The hardest part is maintaining a consistent angle and pressure and there’s only one way to learn that: practice.

stone position

Because you can only apply pressure to part of the blade at a time, you sharpen in sections. A section is complete when you have removed enough material to reach the very tip of the V. You can tell this by feeling for a slight lip along the edge on the opposite side of where you are sharpening. This is called a burr, a thin fold of steel pushed over the edge.

After about ten strokes, check for the burr with your fingertips. Repeat until you can feel it. Important: if you cannot feel a burr, you are not done.

One side is finished only when you can feel a continuous burr from heel to tip. Some areas of the blade may be harder to reach than others which is completely normal. Be patient. We’ll say it again: if you don’t feel a burr along the entire edge, you are not finished.

Once you do feel the burr, move on to the other side. If you’re comfortable using your non-dominant hand, switch sides and repeat the process. If that feels awkward, simply flip the knife so the spine faces you and the edge faces away, keeping the same hands in place.

When you have raised a burr along the entire edge on the second side, you can reduce it by using lighter pressure and only upward strokes. At this point, the edge is formed. Congratulations, take a moment to appreciate your work. Just be aware that your fingers are probably blackened from all the steel you’ve removed.

Now switch to the next finer stone and repeat the process. On fine stones (3000–4000 grit), the burr is harder to feel, but that’s also less critical at this stage since the edge has already been shaped. You are now refining, not forming.

When you finish on the finest stone, you are done. Congratulations! Grab a cutting board, some tomatoes, apples, peppers, onions and celebrate by slicing and chopping to your heart’s content.

A Deeper Look at Whetstones

Japanese whetstones sharpen by abrasion: sharp particles in the stone grind away steel. In the case of Shapton stones, these particles are aluminum oxide, which gradually dull and release from the binder, forming a slurry with steel particles. A stone’s effectiveness depends on the abrasive, the binder, and the hardness of the steel being sharpened.

Below is an overview of the different types of stones and tools.

Diamond Stones

Diamond stones are aggressive tools. They consist of thousands of industrial diamonds bonded to a metal plate with nickel. Grits typically range from #100 (very coarse) to #1000 (relatively fine).

At Cleancut, we strongly recommend only coarse diamond plates for kitchen knives. Fine diamond plates wear out quickly and have a short lifespan. We therefore focus on stones around #150 grit, which are used both for sharpening and for flattening whetstones.

Flattening your stones is essential for two reasons. First, stones wear unevenly and become concave over time. Sharpening on a concave stone results in inconsistent angles and poor results. Second, flattening removes steel residue that clogs the stone and reduces its cutting ability. A flat, clean stone is key to fast and effective sharpening, and a coarse diamond stone is the most efficient way to achieve this.

Diamond stones are also excellent for heavy work: removing chips, repairing broken tips, reshaping severely worn edges, and thinning blades. They work faster than coarse whetstones but leave deeper scratches that must be removed with finer stones.

Coarse Whetstones (#220–320)

These are the roughest whetstones and are used for heavy material removal: thinning thick edges, repairing damage, and restoring heavily worn knives. They are particularly useful for carbon steel knives with a clear shinogi line, where thinning the lower part of the blade improves cutting performance.

Compared to diamond stones, coarse whetstones leave less aggressive scratches and offer better tactile feedback due to the slurry they produce. However, they wear quickly and need frequent flattening. Burr formation is also less distinct, making it harder to know when you’re done. These stones are for major reshaping and must always be followed by finer stones.

#500–800 – The Cleanup Stage

This range bridges coarse and medium stones. It’s rarely ideal as a beginner’s only stone, but for experienced sharpeners it excels at cleaning up scratches from diamond plates or #220 stones. It’s also commonly used in multi-step processes for creating a kasumi finish, a soft, misty finish on the lower blade face.

#1000–2000 – The Workhorse Stone

This is the most important stone in your lineup. It is used every time you sharpen. If the edge is badly worn, starting here can take too long, use a coarser stone first. But for a dull yet intact edge, this is your starting point.

At 10–15 degrees, sharpen until you form a clear burr from heel to tip, then repeat on the other side. This stone is best at producing a crisp, even burr and establishing a clean, symmetrical V-shape is the foundation of true sharpness. A 1000-grit edge is functional but rough and benefits greatly from polishing.

#3000–6000 – Polishing

At this stage, steel removal is minimal. The focus is on refining scratch patterns and increasing sharpness. Polishing reduces the size of the microscopic “teeth” left by coarser stones.

A 1000-grit edge has aggressive teeth that bite well into tomato skins but lack refinement. Polishing to 3000–6000 grit balances sharpness and bite, producing a keen edge that still grips food effectively. Most sharpeners agree that this range is ideal for kitchen knives.

#8000 and Above – Mirror Polish for Enthusiasts

No one needs to go this high for a kitchen knife. Period. But ultra-fine stones produce stunning mirror finishes and extreme sharpness. The downside is reduced bite and faster loss of performance, especially on softer steels. These stones are best reserved for very hard steels and enthusiasts who value refinement over practicality.

Natural Stones – Bite and Beauty

Japanese natural stones are quarried and vary widely in hardness and fineness. They are not measured in grit. When matched with the right knife and technique, they produce a unique combination of mirror polish and excellent bite. They are also the gold standard for kasumi finishes. While no one needs a natural stone to achieve sharpness, they can become a deep and rewarding passion.

Honing Rods: Steel, Ceramic, or Diamond

Honing rods are excellent for maintaining sharpness between sharpenings. Their main difference lies in how much steel they remove.

Steel rod: No steel removal. Used only for European knives. Too soft for Japanese steels.
Ceramic rod: Minimal removal. Suitable for both Japanese and European knives.
Diamond rod: Removes some steel. Restores sharpness quickly but leaves a slightly rougher edge than ceramic.

Over time, honing alone rounds the edge. When it feels like “nothing is happening anymore,” it’s time to return to the stones and resharpen properly.

Sharpening class | The basics