Cleaning a Japanese Knife: Ensuring Lasting Sharpness and Care

Japanese knives are renowned for their exceptional craftsmanship and sharpness, which can make food preparation both a delight and an art form. As with any tool in your kitchen, proper maintenance of quality knives is essential to sustaining their performance and longevity.

In this article, we break down how you should be cleaning a Japanese knife, and before you ask, you can’t put a Japanese knife in the dishwasher! 

Understanding Japanese Knives

Japanese knives are revered for their craftsmanship and cutting prowess, and the history of forging quality knives is richly entwined with culture. They are distinguished by their types and designs, unique steel characteristics, and the specific bevel types employed.

Basic Cleaning Techniques for Japanese Knife

When cleaning, a Japanese kitchen knife requires particular care to maintain its sharpness and prevent damage. You must manually wash and dry the knife, followed by routine maintenance to ensure longevity and optimal performance.

Washing By Hand

To clean a Japanese kitchen knife properly, washing it by hand using a soft sponge or cloth, warm water, and a little dish soap is essential. This process ensures the blade is free from food debris and corrosive elements that could damage the metal over time. Abrasive materials (like steel wool) and harsh chemicals (dishwasher tablets) should be avoided to preserve the integrity of the knife's surface.

It's imperative to clean both the blade and the handle.

Drying and Storing

Immediately after washing, the knife should be thoroughly dried using a soft towel. I recommend using paper towels as old towels can often not dry the knife entirely. Leaving the wet or dirty knife to air dry can lead to oxidation and rust, especially if the blade is high-carbon steel. For storage, a knife sheath/edge guard, magnetic strip, or knife block will protect the blade's sharp edge from moisture and contact with other utensils that could dull the edge.

Daily Maintenance

Daily knife maintenance for non-stainless steel knives includes gently wiping the blade during use. For new non-stainless knives, wiping the blade down regularly until a protective patina forms is essential. This practice removes any immediate contaminants and moisture, preserving the knife's condition. Regular sharpening, per the manufacturer's instructions, ensures the knife remains at optimal sharpness.

Sharpening Japanese Knives

Sharpening a Japanese knife correctly maintains its precision cutting edge. Sharpening knives, particularly carbon steel knives, require specific tools and techniques similar to Western knives. Japanese knives tend to be thinner and have a more aggressive angle to the cutting edge around 20 degrees.

Selecting Sharpening Tools

One must choose the appropriate whetstone - coarse, medium, or fine grit:

- Coarse grit (100-800) is for repairing chips or reshaping an edge.

- Medium grit (800-3000) is suitable for general sharpening.

- Fine grit (3000-8000) is for honing and polishing the knife's edge.

Water whetstones are preferred for Japanese knives due to their softer steel composition.

Sharpening Process

This is not a sharpening guide*, more an overview, however, we will list the crucial steps involved in the sharpening process: 

  1. Soak or wet your whetstone according to the manufacturer's guide.

  2. Secure the stone on a non-slip base.

  3. Hold the knife at the correct angle, typically around 15-20 degrees, and apply edge trailing pressure until a burr is formed..

  4. Repeat on the opposite side of the knife.

  5. Progress through the stone grits Coarse, medium and fine then finish with a leather strop.

*New detailed guide on sharpening coming soon.

Handling and Usage Tips

Mastering Japanese knives' correct handling and usage is crucial for maintaining their sharpness and performance. This includes employing proper cutting techniques such as “the claw” cutting technique, selecting a secure cutting surface, and observing knife safety measures.

Proper Cutting Techniques

Japanese knives are engineered for precision and require a specific cutting motion. You should use a sharp knife with a smooth motion. Excessive force, hacking, smashing and twisting motions can damage the blade or cause injury.

Cutting Surface Selection

The choice of cutting surface significantly affects the edge retention of a Japanese knife. Wooden cutting boards are the best options as they are kinder on the delicate edges. Plastic boards are ok, however, if you are a professional chef these are an industry standard. Avoid cutting on hard surfaces such as glass, marble, or metal, which can rapidly dull and damage the blade.

Knife Handling Safety

When using Japanese knives, safety is paramount. They should always be held securely by the handle or “pinch grip” where the handle meets the blade spine, keeping fingers away from the blade, and stored in a safe place such as a knife block or magnetic strip. Always wash your knife by hand carefully, with the blade facing away from you.

Advanced Care Techniques

Proper maintenance is crucial for the longevity and performance of Japanese knives. These advanced techniques focus on rust prevention, stain removal, and repairing minor blade damage.

Rust Prevention

Knifemakers recommend you keep your Japanese knife dry and oil it regularly to prevent rust. It's recommended to use a light coat of food-grade non-rancid oil after each use. This forms a barrier against moisture and environmental factors that could cause rust.

At The Blade Runner, we think this is excessive. We recommend cleaning and completely drying after each use. This avoids most issues.
However, if you aren't using a knife for long periods we recommend a coat of oil before storage. This includes stainless steel and non-stainless carbon steels.

Removing Stains

 A helpful cheap tool is also a rust eraser, which is useful for restoring shine and removing patina/rust and stubborn stains.

Repairing Chips and Nicks

When addressing chips and nicks, a sharpening stone, preferably a water stone with a grit appropriate for the level of damage, should be used. Use the stone to reshape the edge and gradually restore the knife's sharpness. Smaller imperfections require a medium-grit stone, whereas larger ones may need a coarser grit before refining.

Storing Your Knife

Storing Japanese knives correctly is equally important. It is advisable to store them in a way that ensures the blades do not knock against other utensils, which could cause them to become blunt or chipped.

Knife blocks, magnetic strips, or individual sheaths, such as a Saya, are suitable storage solutions that keep the knives secure while allowing sufficient air circulation to avoid moisture buildup.

Looking to Upgrade Your Professional Chef's Knives?

Japanese kitchen knives have many advantages and are suitable for various skill levels - from beginners to experts. Everyone from cooking enthusiasts to seasoned chefs has a deep appreciation for the aesthetics of Japanese layered steel, and we can help you find the right knife for the task.

If you’re in the market for a Japanese knife with multipurpose versatility, see our range of Japanese chefs knives today.

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