Asaoya Yaichi

カテゴリー: Knife Care & Maintenance

  • Carbon Steel Japanese Knives: 5 Powerful Lessons from My Real Experience

    Carbon Steel Japanese Knives: 5 Powerful Lessons from My Real Experience


    180mm Santoku Aogami #2 Green Micarta Handle with Turquoise Spacer

    Carbon Steel Japanese Knives are often described as difficult to maintain. They can rust, they react with certain foods, and compared with stainless steel, they certainly require a little more attention.

    But after more than 25 years working as a professional chef, I don’t think carbon steel knives are as difficult to live with as many people imagine.

    I currently use Aogami Super, Aogami #2 and VG10 knives in my daily work, and my experience with each one has been quite different. For me, the important thing is not trying to find a completely maintenance-free knife. It is understanding the steel you are using and learning how to look after it.

    If you are looking for Japanese knives in Australia, you can also explore our collection here:

    👉 https://asaoyayaichi.com.au

    Carbon Steel Japanese Knives Can Rust — But That Is Not the Whole Story

    Ishizuchi Kanamono Manufactory

    There is no point pretending otherwise: Carbon Steel Japanese Knives can rust faster than stainless steel.

    I also feel that once a carbon steel knife has developed rust, that particular knife can sometimes seem more likely to rust again.

    However, that does not mean carbon steel is constantly difficult to maintain.

    One knife I currently use regularly is an Aogami Super （青紙スーパー）sujihiki. I use it for fish, meat and vegetables, and sometimes even acidic ingredients such as lemons and limes.

    My routine is extremely simple.

    After using it, I wash it with water and immediately wipe it dry with a towel.

    That’s basically it.

    Despite using it constantly, rust has not been a major problem.

    Perhaps the fact that I use this knife almost every day helps. It is regularly being used, washed, dried and checked rather than being left somewhere for weeks. I cannot say that daily use itself prevents rust, but in my experience, regular care makes carbon steel much easier to manage.

    👉 INTERNAL LINK: Japanese Knife Patina article

    Understanding the difference between normal patina and harmful rust is also important when living with carbon steel.

    My Aogami #2 Knife Is a Different Story


    180mm Kiritsuke Aogami #2 Kurouchi Walnut Octagonal Handle

    My Aogami #2 kurouchi gyuto behaves differently.

    This knife has rusted before, and since then I have found that if I use it, wipe away the moisture and simply leave it for a long period, rust can return.

    So I treat this knife differently.

    When necessary, I deal with the rust through sharpening and use Sabitoru to remove surface rust. If I know I will not use the knife for a while, I apply a thin layer of camellia oil before storing it.

    👉 INTERNAL LINK: Sabitoru Fine article

    Sabitoru has become a useful part of my maintenance routine when small areas of rust appear.

    👉 INTERNAL LINK: Camellia Oil article

    Camellia oil is another simple option when storing carbon steel knives for longer periods.

    This is why I don’t believe owning Carbon Steel Japanese Knives needs to be stressful. Once you have a basic maintenance kit and understand what your knife needs, caring for it becomes part of owning and using the knife.

    Carbon Steel Japanese Knives vs VG10 in Daily Use


    240mm Sujihiki VG10 Hammered 17 Layer Damascus Mahogany

    The VG10 sujihiki I currently use is completely different when it comes to rust.

    Honestly, rust is something I barely think about with this knife.

    But I still treat it almost exactly the same way as my carbon steel knives.

    Use it. Wash it. Dry it.

    That’s all.

    Stainless steel gives you considerably more freedom when it comes to corrosion resistance, but I still don’t believe that means you should leave a good knife wet or dirty.

    There is also another side to stainless steel maintenance that I have noticed during my career.

    Because stainless steel is so easy to live with, it can be tempting to keep using the knife without sharpening it until it becomes seriously dull.

    That can create another problem.

    A Rust-Resistant Knife Is Not a Maintenance-Free Knife


    135mm Petty VG10 Polished Hammered 67 Layer Damascus Green Handle

    In my experience, when some stainless steels become extremely dull, bringing the edge back can feel harder than maintaining the knife regularly.

    This is where people can make a mistake.

    When a knife is not getting sharp quickly enough, there is a temptation to raise the sharpening angle and concentrate only on creating a sharp edge.

    You may get an edge again, but over time the geometry behind that edge can become thicker. Eventually, the knife may feel sharp at the very edge but still struggle to move smoothly through food.

    This connects directly with something I recently wrote about: knife thinning.

    👉 INTERNAL LINK: Japanese Knife Thinning article

    Thinning is not simply about making the edge sharp. It is about maintaining the geometry behind the cutting edge so the knife can continue cutting the way it should.

    That is why regular maintenance matters whether your knife is carbon steel or stainless steel.

    Are Carbon Steel Japanese Knives Really Difficult?


    210mm Sujihiki Aogami #2 Kurouchi Magnolia Handle

    After using different steels professionally, my answer is no.

    Carbon steel requires more awareness of moisture and rust. Stainless steel such as VG10 makes that part much easier.

    But neither should be neglected.

    For me, Carbon Steel Japanese Knives are not difficult knives. They are knives that you need to understand and learn how to live with.

    Wash them after use. Dry them properly. Deal with rust early if it appears. Use camellia oil when storing carbon steel for longer periods. And don’t wait until any knife becomes completely dull before thinking about sharpening.

    That small amount of care can make a very big difference.

    For anyone exploring Japanese Knives Australia, I believe the question should not simply be, “Which steel is best?”

    A better question is:

    Which steel suits the way I cook, sharpen and care for my knives?

    👉 INTERNAL LINK: Japanese Knives Australia: 5 Powerful Choices I Would Make After 25 Years as a Professional Chef

    There is no single steel that is perfect for everyone. Understanding how you actually use your knife is far more important than simply choosing carbon steel or stainless steel.

    👉 Explore more:
    https://blog.asaoyayaichi.com.au

    👉 Visit our online store:
    https://asaoyayaichi.com.au

    Thank you for reading, and I hope to see you again in the next story.

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    Where to See and Buy Our Knives

    Our Partner Stores

    Chanoyu — Nerang, Gold Coast

    Visit Chanoyu and See Our Japanese Knives

    If you are on the Gold Coast, we would love you to visit Chanoyu, a Japanese café in Nerang where you can see and purchase a selection of Asaoya Yaichi knives in person.

    Chanoyu is a lovely place to slow down and enjoy Japanese-inspired food, excellent matcha, coffee and handmade desserts. Its warm, peaceful atmosphere makes it a pleasure to visit, whether you are stopping in for breakfast, lunch or something sweet. We are delighted that our knives have a place there.

    Visit Chanoyu: Shop 6A, 54–58 Nerang Street, Nerang QLD 4211

    Opening hours: Monday to Saturday, 7:00 am–2:00 pm; closed Sunday

    Website: https://www.chanoyucafe.com/

    Instagram: https://www.instagram.com/chanoyugc/

    The selection of knives on display may change. If you are interested in a particular Asaoya Yaichi knife, please contact us through https://asaoyayaichi.com.au before visiting, and we will help you check whether it is available at Chanoyu.

  • Japanese Knife Thinning: 5 Powerful Lessons I Learned After Years of Sharpening

    Japanese Knife Thinning: 5 Powerful Lessons I Learned After Years of Sharpening


    Ishizuchi Kanamono Manufactory 

    Japanese Knife Thinning is something I never thought deeply about, even after more than 25 years working as a professional chef.

    I have sharpened knives throughout my career, but there is something I have noticed many times, particularly with stainless steel knives I have used for years.

    The edge can feel sharp after sharpening, yet somehow the knife does not pass through food as easily as it once did.

    I once borrowed a colleague’s knife at work and was genuinely surprised by how easily it cut. My own knife was sharp too, so why did his knife move through food so much better?

    I had some ideas, but I could not properly explain the reason. So I decided to research Japanese Knife Thinning.

    👉 Looking for Japanese knives in Australia? Explore our collection here:
    https://asaoyayaichi.com.au/japanese-knives-australia

    Japanese Knife Thinning Is Not the Same as Sharpening

    Asaoya Yaichi

    For most of my career, my main purpose when sharpening has been simple: make the knife sharp again.

    Especially at work, I want to finish sharpening quickly and get back to cooking.

    I also know one of my bad habits.

    When I want to create an edge quickly, I sometimes raise the sharpening angle slightly. It reaches the cutting edge faster and gets the job done.

    And I will admit another one: sometimes I am lazy about flattening my whetstone.

    I know I should do it regularly, but knowing that and actually doing it every time are different things.

    👉 INTERNAL LINK: Why Flattening Your Whetstone Matters

    What I had not fully understood was that making the cutting edge sharp and maintaining the overall cutting geometry of a knife are two different things.

    As a knife is repeatedly sharpened, the cutting edge gradually moves higher into the blade, where the steel is generally thicker.

    The edge can still be extremely sharp, but the steel immediately behind that edge can become relatively thick.

    That thickness creates resistance once the edge has entered the food.

    Why Japanese Knife Thinning Started Making Sense to Me


    240mm Sujihiki VG10 Hammered 17 Layer Damascus Mahogany

    This helped explain my experience with my colleague’s knife.

    What surprised me was not simply the sharpness of his edge. It was how easily the entire blade travelled through the ingredient.

    That is where blade geometry becomes important.

    👉 INTERNAL LINK: Japanese Knife Shapes: 5 Powerful Lessons From 25 Years in Professional Kitchens

    A sharp edge starts the cut, but the geometry behind that edge affects what happens next.

    This is also why I started thinking about the difference between some of my stainless knives and the Aogami Super sujihiki I currently use.

    Japanese Knife Thinning and My Aogami Super Sujihiki


    210mm Sujihiki Aogami #2 Kurouchi Magnolia Handle

    With some stainless knives I have owned for years, I have clearly experienced that feeling of the knife becoming harder to push through food.

    My current Aogami Super sujihiki feels different.

    It seems to form an edge quite easily on the stone. I do not need to raise the sharpening angle very much to get the edge I want, so I naturally sharpen it at a relatively low angle.

    👉 INTERNAL LINK: Japanese Knife Steel: 5 Powerful Lessons After 25 Years in Professional Kitchens

    However, I do not think it would be correct to simply say this happens because Aogami Super is better than stainless steel.

    Steel type, hardness, original blade geometry, thickness behind the edge, heat treatment and my own sharpening technique can all influence what I feel.

    I have used VG10 extensively throughout my career, for example, and I still consider it an excellent practical knife steel.

    👉 INTERNAL LINK: VG10 Japanese Knife article

    The difference may partly be the knife itself—and partly the way I sharpen it.

    Japanese Knife Thinning — So How Do You Fix the Problem?

    This was the part I really wanted to understand.

    If the edge is sharp but the knife has become too thick behind the edge, simply sharpening the cutting edge again does not remove that thickness.

    The basic solution is thinning.

    Instead of sharpening only at the normal edge angle, the blade is placed against the whetstone at a much lower angle. Steel is gradually removed from the area immediately behind the cutting edge.

    The purpose is not simply to make another sharp edge. It is to reduce unnecessary thickness and restore a thinner cutting geometry.

    After thinning, the actual cutting edge can then be sharpened normally again.

    👉 INTERNAL LINK: Aogami Super / Carbon Steel article

    However, this is also something I would approach carefully.

    Removing too much steel can change the geometry of the knife. Thinning can also scratch the blade face and alter its original finish. With an expensive Japanese knife, working slowly—or having an experienced professional sharpener do the work—may be safer than aggressively removing steel.

    A Flat Whetstone Matters More Than I Thought

    Why Flattening Your Whetstone Matters

    There was another slightly uncomfortable answer waiting for me.

    The whetstone should be flat.

    When trying to thin a knife at a very low and consistent angle, a dished stone makes controlling the contact between the blade and stone more difficult.

    So perhaps my habit of occasionally avoiding stone flattening was part of the answer all along.

    Prevention matters too.

    Rather than repeatedly increasing the sharpening angle simply because I want to finish quickly, maintaining a lower, consistent angle where appropriate may help preserve the knife’s geometry for longer.

    That does not mean every knife should be sharpened at the lowest possible angle. Different knives, steels and uses require different approaches. But continually making a steeper secondary edge without considering the thickness behind it can eventually change how the knife moves through food.

    What Japanese Knife Thinning Taught Me About Sharpness

    After researching this, I realised something surprisingly simple:

    Sharpening restores the edge. Thinning restores the geometry behind the edge.

    For years, I knew that some knives felt sharp but somehow did not cut like they used to. I also knew that I sometimes sharpened too quickly and occasionally neglected flattening my stones.

    Perhaps I already knew part of the answer. I just did not always want to do it.

    Even after more than 25 years in professional kitchens, there are still things about knives that I do not fully understand.

    That is exactly why I enjoy researching them.

    For anyone looking at Japanese knives in Australia, learning how to maintain the knife over many years can be just as important as choosing the steel, shape or handle when you first buy it.

    👉 Explore more:
    https://blog.asaoyayaichi.com.au

    👉 Visit our online store:
    https://asaoyayaichi.com.au

    Thank you for reading, and I hope to see you again in the next story.

    —————————————————​

    Where to See and Buy Our Knives

    Our Partner Stores

    Chanoyu — Nerang, Gold Coast

    Visit Chanoyu and See Our Japanese Knives

    If you are on the Gold Coast, we would love you to visit Chanoyu, a Japanese café in Nerang where you can see and purchase a selection of Asaoya Yaichi knives in person.

    Chanoyu is a lovely place to slow down and enjoy Japanese-inspired food, excellent matcha, coffee and handmade desserts. Its warm, peaceful atmosphere makes it a pleasure to visit, whether you are stopping in for breakfast, lunch or something sweet. We are delighted that our knives have a place there.

    Visit Chanoyu: Shop 6A, 54–58 Nerang Street, Nerang QLD 4211

    Opening hours: Monday to Saturday, 7:00 am–2:00 pm; closed Sunday

    Website: https://www.chanoyucafe.com/

    Instagram: https://www.instagram.com/chanoyugc/

    The selection of knives on display may change. If you are interested in a particular Asaoya Yaichi knife, please contact us through https://asaoyayaichi.com.au before visiting, and we will help you check whether it is available at Chanoyu.