Kasumi: The Hazy Mist Japanese Knife Finish Explained

Author: Joost Nusselder, author of The Essential Japanese meal planner cookbook Updated February 5, 2023

Knives made with cheap materials can have a finish that wears away quickly, leaving chefs frustrated and out of pocket. That’s where a matte finish comes in, and the Japanese call this KASUMI.

Kasumi is a matte Japanese knife finish, also known as a hazy mist finish, because of its hazy, almost cloudy surface texture. This knife finish is valued for its aesthetic beauty. The Kasumi finish is most commonly found on traditional Japanese styles of knives, such as the Santoku and Yanagiba.

In this guide, I’ll explain what the Kasumi finish is, how it’s achieved, and how it compares to other popular Japanese knife finishes!

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What is a Kasumi finish?

Kasumi is a traditional Japanese knife-making technique used to create a hazy, misty appearance on the blade.

It is a rustic and attractive look with a semi-matte finish that is praised for its aesthetic beauty and practicality.

Kasumi, which roughly translates as “mist,” “cloud,” or “haze,” alludes to the soft steel/iron cladding’s hazy appearance in contrast to the finely polished cutting edge.

Although the Kasumi finish is frequently employed in double-bevel knives as well, it is particularly typical of single-bevel knives, most commonly Yanagibas.

Check out this classy Sakai Ajimasa manufactured yanagiba sushi knife by Houcho to get a taste of the simple beauty of a Kasumi finish.

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This special finish is created by coating the blade with a high-end combination of iron oxide and carbon powder to create an incredibly hard layer on the steel.

This protective layer reduces friction and wear.

When applied to the blade, the Kasumi finish is created by hammering a series of tiny notches, or ‘hits’ into the blade.

This process helps to create a unique texture, which is then polished and finished with a light coating of oil.

The advantage of the Kasumi finish is that it helps to hide scratches and wear, giving the knife a longer-lasting look.

Additionally, because of its matte surface texture, it provides a great degree of grip and control when slicing, chopping, and dicing.

What does “Kasumi finish” mean?

The word Kasumi translates to ‘haze’ or ‘mist,’ and it is often used to describe a specific type of finish on Japanese knives.

Kasumi finish is a traditional Japanese way of polishing a blade.

It’s a hazy appearance of the soft steel or iron cladding in contrast to the fine polished cutting edge.

This elegant finish is very common on traditional-style Japanese blades and gives them a unique and beautiful look.

How is a Kasumi finish made?

Kasumi is a traditional Japanese knife-making technique used to create a hazy, misty appearance on the blade.

To achieve this look, the knife-maker hammers tiny notches into the blade. This makes the knife look like it has a hazy or cloudy surface texture.

This process helps to create a unique texture, which is then polished and finished with a light coating of oil.

The combination of the tiny notches and the matte finish helps to hide scratches and wear, giving the knife a longer-lasting look.

The Kasumi finish can take a long time to create, as it requires an experienced knife-maker who understands the nuances of the process.

What is the difference between a Kasumi and a Hon-Kasumi finish?

Kasumi and hon-kasumi are both traditional Japanese knife-making techniques used to create a hazy, misty appearance on the blade.

The difference between them lies in their composition and the process used to achieve their respective finishes.

Kasumi is created by hammering a series of tiny notches or ‘hits’ into the blade, which helps to create a unique texture.

This process is then followed by polishing and finishing with a light coating of oil.

Hon-Kasumi, on the other hand, is made by using a higher quality steel to create the cladding layer.

This type of finish is more labor-intensive than regular kasumi as it requires more skill and precision.

Generally, the hon-kasumi refers to a premium kasumi finish and is more expensive.

Additionally, hon-kasumi has a shinier and more refined look than regular kasumi.

Both finishes have their advantages, and it’s up to you to decide which one is right for your needs.

What are the advantages of the Kasumi knife finish?

1. Durability: Kasumi knives are incredibly durable, and their hard layers of rust-resistant iron oxide and carbon powder help to protect the blade from corrosion and wear.
2. Aesthetic appeal: The hazy mist finish of Kasumi knives is aesthetically pleasing and provides a unique look.
3. Comfort & control: The matte surface texture is great for providing grip and comfort when slicing, chopping, and dicing. It also helps prevent the food from sticking to the sides of the blade.
4. Low maintenance: The Kasumi finish helps to hide scratches and wear, giving the knife a longer-lasting look.
5. Better edge retention: Kasumi knives are known for their superior edge retention and sharpness, making them ideal for professional chefs or those who want to keep their knives in perfect condition for a long time.

Overall, Kasumi knives are a great choice for anyone looking for an aesthetically pleasing and durable knife with a matte texture.

What are the disadvantages of the Kasumi knife finish?

Although the Kasumi finish has many advantages, there are some drawbacks to consider.

1. Cost: Because they require a lot of skill and time to make, Kasumi knives are usually more expensive than other Japanese knife styles.
2. Maintenance: The Kasumi finish requires regular maintenance and cleaning to keep it looking its best. It is more prone to chips and cracks because it’s made of soft steel.
3. Rust: Despite the hard layers of iron oxide and carbon powder, Kasumi knives can also get rusty.
4. Finish can wear off over time: This cloud-like hazy texture can wear off over time if not properly cared for.

Although Kasumi is a beautiful finish, some people don’t like it because it can be difficult to keep clean and free from rust.

Additionally, because of its soft iron/steel cladding, the blade is more prone to chipping and dulling than a harder material.

Japanese knife finishes: how do they compare to Kasumi?

In this section, we’re going over how Kasumi compares to other popular Japanese knife finishes.

Kasumi vs Kurouchi finish

Kasumi finish is a traditional Japanese style of finish that is created by hammering the blade with a specialized hammer.

This process creates a unique pattern on the blade and gives it a distinct look.

Kurouchi finish, on the other hand, is a modern style of finish that is created by grinding the blade with a grinding wheel.

This process gives the blade a more uniform look and a smoother feel. It’s known as a polished knife finish.

Kasumi finish gives the blade a more rustic and traditional look, while Kurouchi finish gives the blade a more modern and sleek look.

Kasumi finish is more labor intensive and requires more skill to create, while Kurouchi finish is much faster and easier to achieve.

Both finishes have their own unique benefits and drawbacks, so it really comes down to personal preference when deciding which one to go with.

Kasumi vs Kyomen

Kyomen is the shiniest Japanese knife finish, also known as a mirror finish, because of its glossy appearance.

It is created by polishing the blade multiple times with a rotating wheel and high-grit abrasive.

Thus, Kyomen is technically the opposite of the matte, hazy Kasumi texture.

When looking at a blade with a Kyomen finish, it looks almost as if a mirror has been placed on the blade.

The difference between Kasumi and Kyomen finish is quite striking, and it really comes down to personal preference.

If you’re looking for a traditional and rustic look, then Kasumi is the right choice. However, if you’re looking for a sleek and modern look, then Kyomen is the way to go.

Kasumi vs Nashiji

The Nashiji finish is a unique style of finish that resembles the skin of an Asian pear (Nashi).

It’s created by hammering the blade using multiple hammers of various sizes and shapes.

The pattern created by the hammering process varies from knife to knife, but it always has a unique texture that is both beautiful and functional.

When compared to Kasumi finish, Nashiji finish is less glossy and slightly more textured; it also has a slightly higher resistance to rust and corrosion.

Nashiji finish is a great choice for those who want a unique and aesthetically pleasing knife that has a noticeable texture yet still retains its rustic look.

The Kasumi finish, on the other hand, is better suited for those who want a more traditional and rustic look to their knife, and the texture is less visible.

Kasumi vs Damascus

Kasumi finish and Damascus finish are two popular types of blade finishes used in knives.

Kasumi finish is a traditional Japanese technique that involves hammering a blade with a special tool to create a unique pattern.

This technique is used to create a beautiful, decorative finish that is both aesthetically pleasing and durable.

On the other hand, the Damascus finish is a modern technique that involves etching a blade with acid to create a unique pattern.

This technique is used to create a more intricate and detailed finish that is both aesthetically pleasing and durable.

Damascus is known for its wavy pattern and shiny finish, while Kasumi has a more rustic and traditional look.

These two knife finishes are different because of the techniques used to create them.

The look of the Damascus finish is more intricate and complex, while the look of Kasumi is much simpler.

Also learn about Damascus steel (and why it is so special)

Kasumi vs Migaki

Migaki is a Japanese knife finish that involves polishing the blade with several grades of a rotating wheel.

This process gives the blade an even and glossy finish, similar to Kasumi.

The main difference between the two is that Migaki has a much smoother and more uniform feeling with a glossier, smooth polished surface, whereas the Kasumi has a hazy look.

Migaki is a great choice for those who want a glossy and more sophisticated look to their knife, while Kasumi is better suited for those who like the rustic look.

The advantage of Migaki is that it is much faster and easier to achieve than Kasumi.

The disadvantage, however, is that it has a tendency to wear off faster than the Kasumi finish.

Kasumi vs Tsuchime

Tsuchime is a Japanese knife finish that involves hammering the blade with a special tool to create an irregular pattern.

This technique is used to create a unique and aesthetically pleasing finish that is both durable and beautiful.

Tsuchime is also called the ‘hand-hammered knife finish.’

When compared to Kasumi finish, Tsuchime has a rougher and more uneven look, while Kasumi has a smooth appearance.

Tsuchime finish is a great choice for those who want a unique and aesthetically pleasing look to their knife, while Kasumi is better suited for those who prefer a more traditional and rustic look.

The tsuchime finish is usually used on higher-end knives as it requires more skill and experience to create.

The advantage of a Tsuchime finish is that it has a higher resistance to wear and tear, and the food bits don’t stick to the blade.

What is the history of the Kasumi knife finish?

Kasumi knives have a long and storied history.

This finish was first developed by Japanese swordsmiths centuries ago, and it’s still used today.

This knife finish probably dates back to Seki City, Japan, which was the birthplace of the Japanese swordmaking industry.

The technique was used to create knives for samurai and feudal lords, as well as everyday people.

During the Edo period, swordsmiths began to hammer a blade with a unique tool called shigana.

This process created an uneven and rustic finish that was both aesthetically pleasing and highly durable.

Over the years, this process has been refined and improved upon, resulting in the Kasumi finish that we know today.

The idea of the hazy, misty finish has become synonymous with the term ‘Kasumi,’ and it is still widely used in Japan today.

The mist pattern was used to denote the strength and beauty of a blade, as well as its quality.

How to maintain a Kasumi finish

Maintaining a kasumi finish is relatively easy and doesn’t require any special tools or techniques.

Here are some tips to help you keep your knife looking its best:

• Clean the blade with a soft cloth and warm water after each use.
• Do not wash kasumi knives in the dishwasher, as this causes rust and damage.
• Avoid using harsh chemicals or abrasive cleaners.
• Use a high-grit sandpaper to remove any stubborn stains or patina.
• Only sharpen the blade using a traditional Japanese whetstone.
• Polish the blade with a metal polish or Bar Keeper’s Friend to restore the original shine.
• If you want to keep the patina, use a light oil to protect the blade from rust.

Learn more Japanese knife maintenance and care to keep them in the best nick possible

Are Kasumi knives any good?

Yes, Kasumi knives are excellent for both home chefs and professional cooks. They are incredibly sharp, highly durable, and have an aesthetically pleasing finish.

Kasumi knives are made from high-quality Japanese steel and can be used for a variety of tasks, such as slicing, dicing, and chopping.

They are great for precise cuts, as well as tough meat or fish, because the finish doesn’t wear off easily.

Kasumi knives are typically more expensive than other types of knives, but they are well worth the price due to their high quality and long-lasting finish.

They are not as popular as some of the other Japanese finishes, so they’re harder to find.

Conclusion

Kasumi knives are produced with a unique finish of hazy mist, which is called “Kasumi” in Japan.

The main role of this finish is to add a touch of beauty and elegance to the blade while also making it more resistant to wear and tear.

Compared to a mirror-like or polished-finish knife, the matte texture of the Kasumi knife will stand the test of time.

This traditional Japanese hazy mist finish ensures your knife stays sharp longer, resists corrosion better than other finishes, and looks beautiful too.

With Kasumi on your side, you can rest assured, knowing that your knife is built to last.

Read next: Japanese knife handles | What makes ‘Wa’ handles different from Western ones

Check out our new cookbook

Bitemybun's family recipes with complete meal planner and recipe guide.

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Joost Nusselder, the founder of Bite My Bun is a content marketer, dad and loves trying out new food with Japanese food at the heart of his passion, and together with his team he's been creating in-depth blog articles since 2016 to help loyal readers with recipes and cooking tips.