Asaoya Yaichi

タグ: Whetstone

  • 刃返り Kaeri | 5 Essential Truths About the Japanese Knife Burr

    刃返り Kaeri | 5 Essential Truths About the Japanese Knife Burr


    Ishizuchi Kanamono Manufactory 

    I still remember one of my earliest experiences with a Japanese knife burr.

    I had only recently started working as a chef, and like every young cook, I was learning how to sharpen my own knives. One day, while sharpening, a tiny piece of metal suddenly came off the edge.

    I looked at it and genuinely thought part of my knife blade had broken away.

    So I went to the head chef and said something like, “Chef, part of the blade just came off. Is this okay?”

    I can still remember his face.

    He looked at me as if he was thinking, What on earth is this guy talking about?

    Looking back now, it makes me laugh.

    The blade had not fallen off at all.

    What I had seen was a Japanese knife burr coming away from the edge.

    After more than 25 years working as a chef in Japan and Australia, I have sharpened countless knives since then. But recently I realised something: although I had learned to recognise a burr through experience, I had never really stopped to investigate what it actually is.

    So, once again, I decided to look into it.

    What Is a Japanese Knife Burr?

    Asaoya Yaichi

    When sharpening a knife on a whetstone, we are removing a very small amount of steel from the blade. As the abrasive surface of the stone works against the steel, the geometry of the edge gradually changes until the sharpening reaches the very apex.

    At that point, extremely thin metal at the edge can be pushed over to the opposite side. This thin, folded-over material is what we commonly call a burr.

    In Japanese sharpening, it is often referred to as kaeri (返り), or ha-gaeri (刃返り).

    That tiny piece of metal I saw as a young chef was therefore not my knife mysteriously losing its cutting edge. It was material created during the sharpening process.

    If somebody had explained that to me at the time, I probably would not have asked my head chef whether my blade had fallen off.

    But making mistakes is often how we remember things.

    👉 INTERNAL LINK: Read “Whetstone Flattening” here

    Why Does a Japanese Knife Burr Appear?

    A Japanese knife burr can be useful because it gives us information about what is happening at the edge.

    If you sharpen one side and eventually detect a burr along the opposite side, it generally indicates that your sharpening has reached the apex in that area.

    But there is an important distinction.

    Creating a huge burr is not the goal of sharpening.

    When I was younger, I sometimes thought that if I could clearly feel a large burr, I must have sharpened the knife properly. With experience, I learned that continuing to grind away steel simply to make a larger burr is unnecessary.

    You are removing steel every time you sharpen.

    The purpose is to create a clean, properly formed cutting edge—not to remove as much metal as possible.

    👉 INTERNAL LINK: Read “How to Sharpen Japanese Knives” here

    A Bigger Japanese Knife Burr Is Not Necessarily Better

    sharpening Japanese Knife

    This is where sharpening becomes more interesting.

    A large Japanese knife burr may actually be a sign that you have continued sharpening longer than necessary. Once the abrasive has reached the apex and a burr has formed, repeatedly grinding the same side can simply produce more deformation and remove more steel.

    This connects with something I have learned through my own mistakes.

    If you keep sharpening at too high an angle, the geometry around the cutting edge can gradually become thicker. Similarly, using a whetstone that is no longer flat can affect the geometry you are trying to create.

    Sharpening is not only about making a knife feel sharp today. It is also about maintaining the blade over many years.

    👉 INTERNAL LINK: Read “Japanese Knife Bevels | Single vs Double” here

    Removing the Japanese Knife Burr Matters Too

    Forming the burr is only part of the process.

    Eventually, that weakened metal needs to be removed cleanly.

    Simply leaving a large burr attached can create the impression of an extremely sharp knife at first, but that fragile metal may fold, break away or disappear quickly during use.

    This is one reason the finishing stages of sharpening matter.

    I normally use a 1000-grit stone for my main sharpening and then move to a 6000-grit stone for finishing. The lighter work at the end is not about aggressively removing more steel. I am refining the edge and reducing what remains of the burr.

    The more knives I sharpen, the more I feel that the final light touches are just as important as the earlier grinding.

    👉 INTERNAL LINK: Read “The True Value of Japanese Knives” here

    Japanese Knife Burrs Taught Me Something About Sharpening

    Kurouchi

    There is another lesson hidden in that embarrassing story from when I first became a chef.

    Nobody starts out knowing how to sharpen.

    You can read about angles, steels, whetstones and edge geometry, but eventually you have to put a knife on a stone and learn what is happening through your hands.

    Over the years I have used carbon steels, stainless steels and modern high-performance steels, and they do not always feel exactly the same on a whetstone.

    That tactile experience is one of the things I still find fascinating about Japanese knives.

    👉 INTERNAL LINK: Read “Kireaji — What Does Sharpness Really Feel Like?” here

    The Japanese Knife Burr Is a Sign, Not the Goal

    More than 25 years after telling my head chef that “the blade came off,” I can finally give my younger self a better answer.

    Don’t worry.

    The blade didn’t fall off.

    It was just the burr.

    A Japanese knife burr is useful because it can tell us that sharpening has reached the edge, but producing the biggest possible burr does not mean producing the best possible edge.

    For me, that is the real conclusion.

    The burr is a sign during sharpening. It is not the goal of sharpening.

    And perhaps that is why I still remember that confused look on my head chef’s face all these years later.

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

  • 薄刃 Usuba | 7 Powerful Things I Learned About Japanese Knife Thickness

    薄刃 Usuba | 7 Powerful Things I Learned About Japanese Knife Thickness

    After more than 25 years working as a chef in Japan and Australia, I had never really thought seriously about Japanese knife thickness.

    Of course, I have used both thin and thick knives. From experience, I have always felt that thinner knives are generally easier to use. They enter ingredients smoothly, require less effort, and simply feel good when cutting.

    But I had never really asked myself why.

    Since I started selling Japanese knives, I have found myself questioning things I used for years without thinking about them.

    This time, the question was simple:

    When we say a Japanese knife is “thin,” what part of the knife are we actually talking about?

    And does thinner really mean better?

    What Does Japanese Knife Thickness Actually Mean?

    At first, I assumed knife thickness simply meant the thickness of the spine.

    That is certainly one measurement, but it does not tell us everything about how a knife will cut.

    A blade changes thickness from the spine down towards the cutting edge. The area immediately behind the edge can have a major influence on how easily the knife passes through food.

    When I learned this, it immediately made sense from my experience as a chef.

    I have used knives that felt extremely sharp at the edge but somehow required more effort when cutting. I have also used knives that seemed to slip through ingredients almost effortlessly.

    The sharpness of the edge was not necessarily the only difference.

    👉 INTERNAL LINK: Link to “切味 Kireaji” — the article about how we actually experience sharpness.

    Why Does a Thin Japanese Knife Feel Easier to Use?


    165mm Usuba A8 Hammered Damascus Black & Red Octagonal Handle

    A simple cross-section diagram helped me understand this surprisingly well.

    Imagine two sharp blades entering the same ingredient. One remains relatively thin behind the cutting edge, while the other becomes thick very quickly.

    The thinner blade can continue through the food with less resistance. With the thicker blade, the sides of the blade begin pushing against the ingredient and forcing it apart.

    Both edges may be equally sharp, but they can feel completely different in actual use.

    This is why Japanese knife thickness is not simply about one measurement at the spine. The thickness behind the edge, the shoulders and the taper of the blade all contribute to how it moves through food.

    For someone like me who spent years judging knives mainly by how they felt in my hand, it was interesting to finally understand part of the reason behind that feeling.

    How Thin Is a “Thin” Japanese Knife?


    165mm Santoku A10 Damascus Black & Red Octagonal Handle

    I also wondered whether there was a particular measurement where a Japanese knife officially becomes thin.

    There really isn’t one simple number.

    A measurement such as 2 mm at the spine can be useful, but where that measurement is taken matters. A blade may also become progressively thinner towards the tip.

    Two knives with similar spine thickness can therefore feel very different if their geometry behind the edge is different.

    The purpose of the knife matters too.

    A gyuto and a deba should not have the same geometry simply because thinner sounds better. Japanese knives developed into different shapes because they were designed for different jobs.

    👉 INTERNAL LINK: Link to “Japanese Knife Names” — the article about the origins of different Japanese knife types.

    Japanese Knife Thickness: Thinner Is Not Always Better


    Ishizuchi Kanamono Manufactory 

    This was probably the most important thing I learned.

    A thin blade can reduce resistance through food, but that does not mean every knife should be made as thin as possible.

    Thickness also provides strength and stiffness.

    A deba, for example, needs enough strength for working around fish bones and joints. Making it extremely thin would defeat part of the purpose of the knife.

    So instead of asking only:

    “How thin is this knife?”

    I think the better question is:

    “Is this knife thin enough for its purpose while still having the strength it needs?”

    👉 INTERNAL LINK: Link to “Kinkō 均衡” — the article about Japanese knife balance and how a knife feels in use.

    Steel Is Important — But Geometry Matters Too

    Asaoya Yaichi

    Recently, I have been researching steels such as Ginsan, VG10 and SG2.

    Steel is obviously important, but looking into Japanese knife thickness reminded me that the steel name alone cannot tell us how a knife will actually feel when cutting.

    Steel matters. Heat treatment matters. Sharpening matters. Blade geometry matters.

    They all work together.

    This is why two knives made from the same steel can still feel surprisingly different.

    For me as a chef, the final test has always been much simpler than the specifications:

    How does it actually feel when I cut food?

    👉 INTERNAL LINK: Link to the SG2 article — explaining SG2 steel and its characteristics.

    I Have Actually Made My Own Knives Feel Thicker

    Why Flattening Your Whetstone Matters More Than You Think

    This part is not something I only learned while researching this article.

    I have actually experienced it myself — partly because I can be a little lazy with sharpening.

    If I keep sharpening a knife at too steep an angle, I can still create a sharp edge. But over time, the geometry around the edge can become thicker.

    The knife may feel sharp when I test the edge, yet it does not pass through food as easily as it once did.

    I have also made a similar mistake by continuing to use a whetstone after it had become dished instead of flattening it properly.

    I knew I should flatten it.

    Sometimes I just didn’t.

    That uneven stone affected the way I was sharpening, and eventually the knife did not feel the same.

    So when I read about thickness behind the edge and blade geometry, I thought:

    I’ve done this to my own knives.

    That experience taught me something important. Sharpening is not only about making the very edge sharp. Maintaining the geometry behind the edge matters too.

    These days, I pay much more attention to keeping my stones flat and to the angle I am sharpening at.

    Sometimes the best lessons come from doing it wrong yourself.

    👉 INTERNAL LINK: Link to “真価” — the article about sharpening and bringing out the true potential of a Japanese knife.

    So, Do I Think Thinner Japanese Knives Are Better?

    After looking into all of this, I wanted to give myself a clear answer.

    Is a thinner knife a better knife?

    My answer is:

    Not always. But for most of the everyday kitchen knives I use, I still prefer a thinner blade.

    Before I understood the geometry, I already knew from experience that thinner knives often felt easier to use. They entered ingredients more smoothly and required less effort.

    Now I understand more about why.

    Of course, I would not want a deba to be as thin as a light vegetable knife. Different knives need different levels of strength, weight and stiffness.

    But if I am choosing a gyuto, santoku or sujihiki for everyday work, I personally prefer a blade that feels thin and moves through food with as little resistance as possible.

    So after more than 25 years using knives professionally, this is my conclusion:

    Thin does not automatically mean better. But if a knife can keep the strength required for its job, I prefer it thin.

    Maybe my hands already knew that long before I understood the reason.

    I just never stopped to ask why.

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    https://asaoyayaichi.com.au

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

  • Why Do Japanese Knives Rust So Easily? (And Why That’s Not a Bad Thing)

    Why Do Japanese Knives Rust So Easily? (And Why That’s Not a Bad Thing)

    Ishizuchi Kanamono Manufactory

    One of the most common questions I hear is:

    “Why does my Japanese knife rust so easily?”

    It’s a fair question. After all, many people expect an expensive knife to stay shiny and rust-free forever.

    But with traditional Japanese knives, rust isn’t a sign of poor quality. In many cases, it’s actually a sign of what makes the knife special.

    Why Carbon Steel Rusts

    Asaoya Yaichi

    Many handcrafted Japanese knives are made from high-carbon steel, such as Aogami (Blue Steel) or Shirogami (White Steel).

    These steels are loved by professional chefs because they offer exceptional sharpness, excellent edge retention, and are easier to sharpen than many stainless steels.

    The trade-off is that carbon steel reacts more easily with moisture and acidic foods, so it can develop rust if left wet.

    My Own Experience

    I learned this the hard way.

    Even after rinsing my knife with water, I once left it sitting for a while after cutting citrus fruit.

    When I came back, small spots of rust had already started to appear.

    It wasn’t because the knife was poorly made.

    It was because the acid from the citrus remained on the blade long enough to react with the carbon steel.

    Since then, I’ve made it a habit to wash my knives, dry them immediately, and never leave them sitting wet.

    Rust Doesn’t Mean a Bad Knife


    180mm Kiritsuke Aogami #2 Kurouchi Walnut Octagonal Handle

    Many of Japan’s finest kitchen knives are made from carbon steel.

    Professional chefs continue to choose them because they value cutting performance over convenience.

    A little extra care is a small price to pay for a knife that delivers incredible sharpness and can last for decades.

    How to Prevent Rust

    Knife Care

    Keeping a carbon steel knife in great condition is simple.

    • Wash it soon after use.
    • Dry it thoroughly with a clean towel.
    • Never leave it soaking in water.
    • Be extra careful after cutting acidic foods such as lemons, limes, or tomatoes.
    Tsubaki Oil
    • If storing the knife for an extended period, apply a thin coat of camellia oil (tsubaki oil), which has traditionally been used in Japan to protect carbon steel from rust. If you don’t have camellia oil, a small amount of food-grade cooking oil can also be used as a temporary alternative.

    What If Rust Already Appears?

    Don’t panic if you notice rust on your knife.

    In many cases, light surface rust can be removed before it causes any serious damage.

    Depending on the severity of the rust, you may be able to remove it by:

    • Sharpening the blade on a whetstone.
    • Gently polishing the affected area with fine-grit sandpaper.
    • Using a rust eraser designed for knives and tools, such as products commonly known in Japan as Sabitoru.

    The most important thing is to deal with rust as soon as you notice it. The longer rust remains on the blade, the more difficult it can become to remove.

    Prevention Is Better Than Restoration


    240mm Thick Deba Aogami #2 Kurouchi Walnut Handle

    One of the best ways to keep a carbon steel knife in excellent condition is to prevent rust from forming in the first place.

    Once rust starts to develop, the affected areas can become more susceptible to rusting again if they are not properly cleaned and protected.

    That’s why it’s best to care for your knife from the day you buy it. Keeping the blade clean and dry from the beginning is the easiest way to maintain both its appearance and its cutting performance for years to come.

    As with most knife care, prevention is always easier than restoration.

    Final Thoughts


    180mm Santoku VG10N 33 Layer Damascus Green Marble Handle Rainbow Spacer Blue

    Carbon steel knives aren’t difficult to own—they’re simply different.

    Once you understand how to care for them, you’ll see why so many professional chefs continue to choose carbon steel over stainless steel.

    However, if you’re not confident that you’ll be able to give a carbon steel knife the care it needs, there’s nothing wrong with choosing a stainless steel knife instead.

    A knife that suits your lifestyle is always a better choice than one that causes unnecessary stress.

    At Asaoya Yaichi, we proudly offer authentic handcrafted Tosa knives made by skilled Japanese craftspeople, including both carbon steel and stainless steel options.

    If you’re looking for an authentic Japanese knife, we’d be happy to help you find the one that’s right for you.

    Explore our collection at:

    https://www.asaoyayaichi.com.au

    From Tosa, Japan, to your kitchen.

  • Why Flattening Your Whetstone Matters More Than You Think

    Why Flattening Your Whetstone Matters More Than You Think

    When I first became a chef, I had no idea that whetstones needed to be flattened.

    For nearly two years, I sharpened my knives on the same stone without ever checking if it was still flat.

    The knives became sharp enough for work, so I assumed everything was fine.

    Then one day, while visiting Japan, I took one of my knives back to the shop where I had bought it.

    The craftsman looked at it and simply said,

    “That’s no good!”

    It was a little embarrassing, but it became one of the most valuable lessons I ever learned about sharpening.

    What Is Whetstone Flattening?

    Whetston

    Every time you sharpen a knife, your whetstone slowly wears down.

    Because the centre is used the most, it gradually becomes lower than the edges.

    Even if you can’t easily see it, that slight hollow can affect how your knife is sharpened.

    Flattening simply restores the whetstone back to a perfectly flat surface.

    Why Is It Important?


    165mm Kiritsuke Thick Deba Aogami #2 Kurouchi Walnut Octagonal Handle

    Japanese knives are designed with precise edge geometry.

    If your whetstone isn’t flat:

    • The edge won’t contact the stone evenly.
    • It’s much harder to keep a consistent sharpening angle.
    • The bevel can become uneven.
    • Sharpening becomes less predictable.

    Sometimes people think they’ve forgotten how to sharpen.

    In reality, the problem may simply be the condition of the whetstone.

    How to Flatten Your Whetstone

    I simply use a standard flattening stone designed for whetstones.

    Before I begin, I draw a light grid across the whetstone using a permanent marker.

    There’s no need to colour the whole surface—just a simple grid is enough.

    Wet both stones and rub them together using even pressure.

    And the house was a rental.

    As the surface becomes flat, the marker lines gradually disappear.

    If some lines remain, those areas are still lower than the rest of the stone.

    Once all the lines disappear evenly, rinse the stone thoroughly and it’s ready to use again.

    It only takes a few minutes, but it makes a huge difference to your sharpening.

    A Funny Story From One of My Former Chefs

    Why Flattening Your Whetstone Matters

    One of the chefs I used to work with had a very different way of flattening his whetstones.

    Instead of using a flattening stone, he rubbed them directly on the smooth concrete in his backyard.

    To be fair…

    It actually worked surprisingly well.

    A smooth concrete surface allows you to apply good pressure and removes the high spots quite effectively.

    The only problem was that it left grey sharpening marks and stains all over the concrete.

    Even now, I sometimes wonder if everything went smoothly when he moved out!

    So yes, it can work in an emergency.

    But unless you’re prepared to explain mysterious grey stains to your wife, partner, or landlord, I probably wouldn’t recommend it.

    If you’re renting, it’s definitely best to avoid using your driveway or patio.

    5 Common Mistakes That Damage Japanese Knives

    If you really prefer this method, a better option would be to buy a smooth concrete paver or a flat tile and use that instead.

    Just make sure it’s genuinely flat. If the surface isn’t flat, your whetstone won’t be either. Also, some tiles are so smooth that they don’t remove material very effectively.

    For consistent results, a proper flattening stone is still the easiest and most reliable solution.

    What I Learned


    210mm Gyuto VG10 Polished Hammered 67 Layer Damascus Green Handleす

    Back then, I thought that as long as my knife became sharp, I was doing everything correctly.

    Now I know that good sharpening doesn’t begin with the knife.

    It begins with a flat whetstone.

    Sometimes the smallest maintenance habits make the biggest difference.

    Looking After Your Japanese Knife

    A quality Japanese knife doesn’t require complicated maintenance.

    Keep it clean, dry it properly, sharpen it when needed, and remember to maintain your whetstone as well.

    With proper care, a handcrafted Tosa knife can last for many years.

    At Asaoya Yaichi, we’re proud to offer authentic handcrafted Tosa knives made by skilled craftsmen in Kochi, Japan.

    Explore our collection at:

    www.asaoyayaichi.com.au

    From Tosa, Japan, to your kitchen.

  • The Biggest Myth About Japanese Knives: What 25 Years as a Chef Taught Me

    The Biggest Myth About Japanese Knives: What 25 Years as a Chef Taught Me


    165mm Usuba A8 Hammered Damascus Black & Red Octagonal Handle

    If you’ve spent any time researching Japanese knives online, you’ve probably heard the same warnings.

    “They rust.”
    “They chip easily.”
    “They’re only for professional chefs.”

    After more than 25 years working as a chef in both Japan and Australia, I’ve learned that while there’s some truth behind these statements, they’re often misunderstood.

    The biggest problem isn’t the knives themselves.

    It’s the myths surrounding them.

    Let’s look at the ones I hear most often.

    Myth 1 – They’re Too Difficult to Maintain

    https://ishizuchiknives.com

    Many people believe owning a Japanese knife means spending hours sharpening and maintaining it.

    In reality, good habits matter far more than constant sharpening.

    Simply washing, drying, and storing your knife properly after each use will prevent most problems.

    I don’t sharpen my knives every day—and neither do most professional chefs.

    Japanese knives aren’t difficult to own.

    They simply reward good habits.

    Myth 2 – They Rust Instantly

    Knife Care

    Yes, carbon steel can rust.

    But in my experience, rust usually happens because a knife is left wet or dirty for too long.

    With basic care, a carbon steel knife can last for decades.

    I still regularly use a Yanagiba knife that’s around 40 years old. It has been part of my cooking journey for over 20 years, and it continues to perform beautifully.

    Good care—not constant worry—is what makes a knife last.

    Myth 3 – They’re Only for Professional Chefs

    This is probably the biggest misconception.

    Professional chefs certainly appreciate the performance of Japanese knives, but they’re far from the only people who buy them.

    During my visits to Ishizuchi Kanamono Seisakusho, a long-established knife wholesaler based in Ehime Prefecture that works closely with Tosa blacksmiths, I was told something that surprised me.

    Most international visitors who purchase Japanese knives from places like Kappabashi in Tokyo aren’t professional chefs at all.

    Many are home cooks who simply enjoy preparing food, while others buy them because they admire Japanese craftsmanship and want to own something made by skilled artisans.

    I was also told that Santoku and Sujihiki knives are among the most popular choices for international customers.

    That makes perfect sense.

    A Santoku is an excellent all-purpose knife for everyday cooking, while a Sujihiki is ideal for slicing meat and fish cleanly and precisely.

    Their popularity shows that Japanese knives aren’t just professional tools—they’re practical, enjoyable to use, and appreciated by people who simply love cooking.

    Myth 4 – They Chip Too Easily

    Any hard steel knife can chip if it’s used incorrectly.

    Frozen food, bones, twisting the blade, or using glass cutting boards can damage almost any premium knife.

    However, one of the reasons I enjoy recommending handcrafted Tosa knives is their practical, durable design.

    In my own kitchen, I’ve used a Tosa Gyuto to remove the heads of large fish such as salmon and yellowtail without experiencing edge chipping.

    That doesn’t mean I recommend using a Gyuto as a substitute for a Deba knife, and no knife is completely immune to damage if misused.

    But that real-world experience has given me tremendous confidence in the durability of well-made Tosa knives.

    For many home cooks, that extra toughness provides valuable peace of mind without sacrificing the outstanding cutting performance that Japanese knives are known for.

    What Really Matters

    The best Japanese knife isn’t necessarily the most expensive one.

    It’s the one that suits your cooking style, feels comfortable in your hand, and makes you want to cook more often.

    After more than 25 years as a chef, that’s the lesson I value most.

    A great knife should make cooking more enjoyable—not more intimidating.

    Looking for Your First Japanese Knife?

    Asaoya Yaichi look

    If you’ve always wanted to own a handcrafted Japanese knife but thought they were too delicate or too difficult to maintain, I hope this article has changed your perspective.

    At Asaoya Yaichi, we carefully select handcrafted Tosa knives made by skilled Japanese blacksmiths—knives that are built not only for exceptional sharpness, but also for real everyday use.

    Whether you’re a professional chef or buying your very first Japanese knife, there’s a knife that can become a trusted part of your kitchen for years to come.

    Explore our collection of authentic handcrafted Tosa knives and discover the difference for yourself.

    👉 https://www.asaoyayaichi.com.au

    From Tosa, Japan, to your kitchen.

  • 5 Common Mistakes That Damage Japanese Knives

    5 Common Mistakes That Damage Japanese Knives

    Lessons I’ve Learned After More Than 25 Years as a Chef


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

    Japanese knives are often described as delicate or difficult to maintain.

    From my experience, that’s not true.

    After more than 25 years working as a chef in both Japan and Australia, I’ve found that most damage doesn’t happen while you’re cooking—it happens afterwards.

    Rust, cracked handles, warped blades, and unnecessary repairs are often the result of a few simple habits that are easy to avoid.

    Here are the five most common mistakes I’ve seen over the years, including a few I’ve learned from my own experience.

    1. Leaving the Knife Wet After Use

    If I had to choose the biggest cause of rust, this would be it.

    After cooking, it’s easy to leave a knife on the cutting board or beside the sink while cleaning up.

    Unfortunately, even a short period of moisture combined with food residue can start the rusting process.

    Carbon steel is especially vulnerable, but stainless steel isn’t completely immune either.

    A simple routine makes all the difference:

    • Wash the knife soon after use.
    • Dry it thoroughly.
    • Store it somewhere dry.

    Those extra 30 seconds can add years to your knife’s life.

    2. Only Rinsing the Knife After Cutting Citrus Fruits

    Most people know that citrus fruits such as lemons and limes can affect a knife because of their acidity.

    What I’ve personally experienced, however, is that simply rinsing the blade with water isn’t always enough.

    I have rusted a knife myself after cutting citrus and only washing it with water.

    Acid and juice can remain on the blade, especially near the edge, the heel, or where the blade meets the handle.

    After cutting citrus, I always recommend:

    • Wash the knife properly with mild dishwashing liquid.
    • Rinse with clean water.
    • Dry it immediately and completely.

    It’s a small habit that can prevent unnecessary rust.

    3. Ignoring Small Rust Spots

    Small rust spots are much easier to deal with than deep rust.

    Once rust starts penetrating into the steel, removing it becomes much more difficult and time-consuming.

    I’ve learned that preventing rust is always easier than restoring a damaged blade.

    If you notice rust beginning to form, don’t leave it for another day.

    Deal with it early.

    Your knife will thank you for it.

    4. Washing the Knife with Very Hot Water

    Many people know not to use a dishwasher.

    What isn’t discussed as often is washing a knife by hand with very hot water.

    In my experience, repeatedly exposing a knife to very hot water can shorten its lifespan.

    The blade can be placed under unnecessary stress from repeated temperature changes, while the wooden handle suffers even more.

    Over time, excessive heat can cause the handle to:

    • Dry out
    • Expand and contract repeatedly
    • Develop small cracks
    • Split
    • Loosen around the tang
    • Eventually begin to rot from moisture entering through damaged areas

    Once a wooden handle starts cracking, water and food residue can work their way inside, making it more difficult to keep clean and shortening the life of the handle.

    Warm water is all you need.

    Wash the knife quickly, dry both the blade and the handle immediately, and avoid soaking it.

    5. Putting the Knife in the Dishwasher

    This is probably the most well-known mistake, but it’s still worth mentioning.

    Dishwashers expose knives to:

    • High temperatures
    • Strong detergents
    • Long periods of moisture
    • Contact with other utensils

    These conditions can damage both the blade and the wooden handle.

    Even if no damage is visible after one cycle, repeated dishwasher use can significantly shorten the knife’s lifespan.

    A handcrafted Japanese knife deserves to be washed by hand.

    Fortunately, that only takes a minute.

    Japanese Knives Aren’t Difficult to Maintain

    One of the biggest misconceptions is that Japanese knives require complicated maintenance.

    In reality, they don’t.

    Simply remember to:

    • Wash the knife soon after use.
    • Don’t leave it wet.
    • Properly wash it after cutting citrus fruits.
    • Remove rust before it becomes serious.
    • Avoid very hot water.
    • Never use a dishwasher.
    • Dry both the blade and the wooden handle thoroughly.

    None of these steps are difficult.

    They simply become good habits.

    Final Thoughts

    After more than 25 years in professional kitchens, I’ve learned that good knife care isn’t about doing something special.

    It’s about avoiding a few simple mistakes.

    The difference between a knife that lasts five years and one that lasts several decades often comes down to daily habits.

    I still own a knife that has been in my family for over 40 years.

    The reason it’s still in use today isn’t because it received special treatment.

    It’s because someone took the time to wash it, dry it, and care for it properly after every use.

    If you do the same, a quality Japanese knife can reward you with many years of reliable service.

    Looking for a Knife Built to Last?

    Asaoya Yaichi

    The handcrafted Tosa knives available from Asaoya Yaichi are made by skilled Japanese craftspeople and designed for real daily use.

    With proper care, they can remain reliable kitchen tools for many years.

    Explore our collection of authentic handcrafted Tosa knives and find a knife that suits your cooking style.

    From Tosa, Japan, to your kitchen.

    Ready to find the right knife for your kitchen?

    Explore the Asaoya Yaichi collection of authentic handcrafted Tosa knives:

    https://www.asaoyayaichi.com.au

  • How Often Should You Really Sharpen a Japanese Knife?

    How Often Should You Really Sharpen a Japanese Knife?

    A Chef’s Honest Perspective


    I use an electric sharpener at home.

    One of the most common questions I hear is:

    “How often should I sharpen my Japanese knife?”

    The answer might surprise you.

    After more than 25 years working as a chef in both Japan and Australia, I’ve learned that there isn’t a single correct answer.

    Every chef develops their own routine based on the knives they use, the ingredients they prepare, and the standards they set for themselves.

    My Routine May Surprise You


    240mm Thick Deba Aogami #2 Kurouchi Walnut Handle

    To be completely honest, I don’t fully sharpen my knives every day.

    In my own routine, I usually do a proper sharpening on a 1000-grit whetstone about once a week.

    During service, if I feel the edge beginning to lose its bite, I’ll often touch it up lightly on a 6000-grit finishing stone to keep the knife performing consistently until my next full sharpening.

    That approach has worked well for me throughout many years in professional kitchens.

    Every Chef Is Different


    A Chef’s Daily-Cared-For Knife

    At the same time, I’ve worked alongside chefs whose approach is completely different.

    Some sharpen their knives every single day.

    Some go even further, polishing their blades with mirror-polishing compounds until they achieve an incredibly refined finish.

    When you use one of those knives, the difference can be astonishing.

    I’ve borrowed colleagues’ knives before and genuinely thought,

    “Wow… this thing is unbelievably sharp.”

    Those moments remind me that there is always something new to learn.

    I’m Still Learning Too

    People sometimes assume that because I’ve been a chef for over 25 years, I must be a master sharpener.

    The truth is, I don’t see myself that way.

    There are many chefs whose sharpening skills are better than mine, and I’m perfectly happy to admit that.

    Sharpening is a craft in itself.

    Like cooking, it’s something you can continue improving for a lifetime.

    I believe being honest about that is more valuable than pretending to know everything.

    The Goal Isn’t Perfection

    Otori,Scallop,Scampi Sashimi

    For professional chefs, the goal isn’t always creating the sharpest knife imaginable.

    The real goal is having a knife that performs reliably, safely, and consistently throughout service.

    For home cooks, the standard is even simpler.

    You don’t need to sharpen your knife every week just because a professional chef does.

    If your knife still cuts cleanly and feels comfortable to use, it’s probably doing exactly what you need.

    Listen to Your Knife

    Instead of following someone else’s schedule, learn to pay attention to your knife.

    Is it crushing tomatoes instead of slicing them?

    Does it slip instead of biting into ingredients?

    Does it require more pressure than it used to?

    Those are much better indicators than the calendar.

    Every knife tells you when it’s time.

    You simply have to learn how to listen.

    A Final Thought


    When I’m not in the kitchen, I’m probably squid fishing.

    One lesson I’ve learned throughout my career is that there is no single “correct” way to care for a Japanese knife.

    Different chefs have different routines.

    Different kitchens have different demands.

    What matters most is finding a routine that keeps your knife performing well and encourages you to enjoy using it.

    A well-maintained Japanese knife isn’t about chasing perfection.

    It’s about building a relationship with a tool that can serve you for many years.

    Looking for a Japanese knife worth caring for?

    At Asaoya Yaichi, we carefully select authentic handcrafted Tosa knives made by skilled Japanese blacksmiths.

    Whether you’re buying your first Japanese knife or adding to an existing collection, our goal is to help you find a knife you’ll enjoy using—and maintaining—for years to come.

    Explore our collection here:

    https://www.asaoyayaichi.com.au

  • A Knife That Earned My Respect

    A Knife That Earned My Respect

    Part 2 – A Knife That Grows With You

    Knife Care

    The more I used traditional Tosa knives, the more I realised something.

    The blacksmith’s work doesn’t end when the knife leaves the forge.

    In many ways, that’s where the next chapter begins.

    A handcrafted knife is not meant to remain exactly as it was on the day it was made.

    It is meant to grow alongside the person who uses it.

    That may sound unusual at first.

    But after spending more than twenty-five years working as a chef, I have come to believe it is true.

    A Knife That Learns Your Hands


    A Knife That Learns Your Hands

    Every chef works differently.

    Some prefer a finer edge for delicate slicing.

    Others leave a little more strength behind the edge for heavier work.

    Some sharpen frequently.

    Others wait until the knife tells them it is time.

    None of these approaches are necessarily right or wrong.

    Over time, every sharpening subtly changes the knife.

    Every service leaves another memory.

    Every meal adds another chapter.

    Eventually, something remarkable happens.

    The knife no longer feels like a tool made by someone else.

    It feels like your knife.

    That is why I often say a great knife isn’t finished by the blacksmith alone.

    The blacksmith begins the story.

    The owner completes it.

    Beauty Beyond Perfection


    240mm Thick Deba Aogami #2 Kurouchi Walnut Handl

    When many people imagine a premium Japanese knife, they picture a flawless mirror finish.

    I used to think the same way.

    Today, I see beauty differently.

    A softened Kurouchi finish.

    A natural patina on carbon steel.

    Small marks left behind after years of careful sharpening.

    These are not imperfections.

    They are evidence of a knife that has been trusted.

    To me, that is a far more meaningful kind of beauty.

    It reminds me of the Japanese philosophy often described as Wabi-Sabi—finding beauty in authenticity, simplicity and the passage of time.

    The character of a handcrafted knife is not frozen on the day it is forged.

    It continues to evolve with every meal it helps create.

    Different Regions, Different Traditions


    150mm Kiritsuke Thick Deba Aogami #2 Kurouchi Walnut Octagonal Handle

    Japan is home to many extraordinary knife-making regions.

    Sakai is renowned for its precision and refined finishing.

    Kyoto is admired for its elegance and long tradition of craftsmanship.

    I have enormous respect for both.

    Tosa simply tells a different story.

    Its blacksmiths were shaped by a region where tools were expected to work hard every single day.

    Generations of craftsmen forged tools for farming, forestry and fishing long before they became known for kitchen knives.

    That heritage is still visible today.

    A Tosa knife doesn’t try to hide where it came from.

    Its forged texture, Kurouchi finish and practical design proudly reflect its working roots.

    That is exactly what many people come to appreciate.

    Some collectors are captivated by the refined elegance of Sakai or Kyoto.

    Others are drawn to the rugged honesty of Tosa.

    Many enjoy collecting knives from different regions because each one tells a different story about Japan’s remarkable craft traditions.

    It isn’t about deciding which is better.

    It is about appreciating the unique character each tradition offers.

    Why Asaoya Yaichi Exists

    Ishizuchi Kanamono Manufactory

    People sometimes ask why I decided to start Asaoya Yaichi.

    The answer is simple.

    I wanted to introduce Australians to authentic handcrafted Tosa knives.

    Not because they are fashionable.

    Not because they are the most expensive.

    But because I believe they deserve to be recognised for what they truly are.

    For too long, I have seen mass-produced knives marketed as “Japanese knives” without representing the traditions that made Japanese craftsmanship respected around the world.

    That isn’t what I wanted to share.

    I wanted to introduce knives with a genuine story.

    Knives made by skilled blacksmiths whose techniques have been handed down through generations.

    Knives that improve with care instead of losing their value.

    Knives that can still be used decades from now—just like the Yanagiba my mother used for around twenty years before passing it on to me, and that I’ve continued using for another twenty.

    That knife reminds me that a truly great knife isn’t measured by how it looks on the first day.

    It’s measured by how faithfully it serves over a lifetime.

    More Than Selling Knives

    Working with Ishizuchi Kanamono Seisakusho has strengthened that belief.

    For more than a century, they have remained committed to supporting authentic craftsmanship and the people behind it.

    That philosophy reflects exactly what I hope Asaoya Yaichi can become.

    Not simply a shop.

    But a bridge.

    A bridge between the traditional blacksmiths of Tosa and the people who will use their work every day here in Australia.

    Every knife carries the skill of the craftsman who forged it.

    But its future belongs to the person who chooses to use it.

    That relationship is what makes handcrafted knives so special.

    A Final Thought

    If there is one lesson I have learned after more than twenty-five years as a chef, it is this:

    The best knife is not always the one that impresses you on the first day.

    Sometimes, the best knife is the one that quietly earns your respect over many years.

    That is exactly what happened to me.

    I didn’t fall in love with Tosa knives the moment I first picked one up.

    I fell in love with them after cooking with them.

    After sharpening them.

    After trusting them.

    That journey changed the way I looked at knives forever.

    It is also the reason Asaoya Yaichi exists today.

    If you’ve always believed traditional Japanese knives are difficult to maintain, you may be surprised.

    With a little knowledge and regular care, a handcrafted knife can stay with you for decades.

    In future articles, I’ll be sharing practical knife care, sharpening techniques, and maintenance tips to help you get the very best from your knife—whether you’re a professional chef or cooking at home.

    If this article encourages even one person to look beyond appearances and discover the craftsmanship, history and spirit behind a traditional Tosa knife, then I believe I have achieved something meaningful.

    Because we are not simply preserving knives.

    We are helping preserve the people, the skills and the traditions that continue to shape them.

    Explore Authentic Tosa Knives

    If this story resonates with you, I’d be honoured to welcome you to Asaoya Yaichi.

    Every knife in our collection is carefully sourced through Ishizuchi Kanamono Seisakusho and handcrafted by traditional blacksmiths in Tosa, Japan.

    These are not simply knives to own.

    They are knives to use.

    To maintain.

    To sharpen.

    To grow with.

    Explore our handcrafted Tosa knife collection:

    👉 https://www.asaoyayaichi.com.au

    Read more articles about Japanese knives and knife care:

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

    Thank you for taking the time to read my story.

    The blacksmith begins the story.

    Time shapes the knife.

    The person who uses it gives it its soul.

  • How to Care for Your Japanese Knife | Keep It Sharp for Years

    How to Care for Your Japanese Knife | Keep It Sharp for Years

    Buying a quality Japanese knife is just the beginning.

    With proper care, a handcrafted knife can provide exceptional performance for many years—often decades. Unfortunately, many knives lose their edge prematurely, not because they’re poor quality, but because they’re cared for incorrectly.

    After more than 25 years working as a chef in Japan and Australia, I’ve seen many excellent knives damaged by simple mistakes that are easy to avoid.

    1. Wash Your Knife by Hand

    Always wash your knife by hand using warm water and a mild detergent.

    Never leave it soaking in the sink, and avoid putting it in the dishwasher. The high heat, harsh detergents, and contact with other utensils can damage both the blade and the handle.

    After washing, dry the knife immediately with a soft towel.

    2. Use the Right Cutting Board

    A quality knife deserves a quality cutting surface.

    Wooden and soft rubber cutting boards are ideal because they are gentle on the edge.

    Glass, ceramic, marble, granite, or very hard plastic boards will dull even the best knife much faster.

    3. Don’t Twist or Pry

    Japanese knives are designed for precise slicing.

    Avoid twisting the blade while cutting or using it to pry frozen food, bones, or hard shells. Doing so can chip or damage the edge.

    Instead, let the knife do the work with smooth, controlled cuts.

    4. Store Your Knife Properly

    Never throw your knife loosely into a drawer.

    Use a knife block, magnetic knife rack, or a blade guard to protect the edge and improve safety.

    Proper storage also helps prevent accidental damage to the blade.

    5. Sharpen Before It Becomes Completely Dull

    Many people wait until their knife struggles to cut before sharpening it.

    In reality, regular maintenance keeps the knife performing at its best and usually removes less steel over time.

    A whetstone remains the best method for maintaining a traditional Japanese knife.

    Carbon Steel vs Stainless Steel

    Different steels require different levels of care.

    Carbon steel can develop a beautiful natural patina with use, but it should always be dried immediately after washing to prevent rust.

    Stainless steel is more resistant to corrosion and generally easier to maintain, making it a great choice for many home cooks.

    Neither is “better”—they simply suit different users and cooking styles.

    A Good Knife Is Meant to Last

    One of the greatest pleasures of owning a handcrafted Japanese knife is watching it improve with age.

    As the handle develops character and the blade is maintained over the years, the knife becomes uniquely yours.

    With proper care, a handcrafted knife isn’t simply a kitchen tool—it’s an investment that can accompany you through thousands of meals.

    At Asaoya Yaichi, we carefully select authentic handcrafted knives from Tosa, Japan, believing that quality craftsmanship deserves proper care and appreciation.

    If you’re looking for a genuine Japanese knife that will last for many years, we invite you to explore our collection.

    Browse our collection:
    https://www.asaoyayaichi.com.au

    Read more knife guides:
    https://blog.asaoyayaichi.com.au