Japanese Knife Care Guide: Cleaning, Storage & Maintenance

May 8, 2024 Leigh Boys

Japanese knives are designed for exceptional sharpness and performance. Proper care will help keep your knife sharper for longer while reducing the risk of rust, chipping and unnecessary wear.

Knife Care: Quick Start

✅ Hand wash only

✅ Dry immediately after use

✅ Use wood or quality plastic cutting boards

✅ Store in a saya, knife block or on a magnetic strip

✅ Sharpen with whetstones

❌ Never put in the dishwasher

❌ Never cut frozen food or bones

❌ Never leave soaking in water

❌ Never store wet

Common Mistakes

Avoid:

❌ Dishwasher use

❌ Cutting frozen food

❌ Twisting the blade in food

❌ Scraping food off the board with the edge

❌ Cutting on glass, stone or metal surfaces

❌ Storing the knife wet

What About Carbon Steel?

Carbon steel knives can develop a natural patina over time. This blue, grey or dark discolouration is normal and helps protect the blade. A patina is not rust and is generally considered desirable on carbon steel knives.

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

Wash by hand with warm water and mild dish soap.
Use a soft sponge or cloth.
Clean both blade and handle.
Avoid abrasive cleaners or steel wool.
Never place Japanese knives in the dishwasher.

Tip: Wipe carbon steel knives regularly during use, especially when cutting acidic ingredients such as onions, citrus, tomatoes, or fruit.

Drying and Storing

Dry immediately after washing.
Do not leave knives to air dry.
Store in a saya, edge guard, knife block or on a magnetic strip.
Keep the edge away from other utensils and hard surfaces. Avoid storing Japanese knives loose in a utensil drawer.

Daily Maintenance

For carbon steel and other non-stainless Japanese knives, a little daily care goes a long way.

Wipe the blade regularly during use, especially when cutting acidic ingredients such as onions, citrus, tomatoes, or fruit.
Never leave the knife sitting wet on the bench or in the sink.
Wash and dry the knife promptly after use.
New carbon steel knives should be wiped more frequently until a protective patina develops.
Keep the edge sharp with regular whetstone maintenance rather than waiting for the knife to become completely dull.

These simple habits help prevent rust, reduce staining, and keep your knife performing at its best.

Sharpening Japanese Knives

Regular sharpening is essential for maintaining the performance and precision of a Japanese knife. Most Japanese knives are ground thinner and sharpened to a more acute angle than Western knives, allowing them to achieve exceptional sharpness.

Choosing a Whetstone

Different grit ranges serve different purposes:

Coarse (120–800 grit) – Repairs chips, removes damage, and restores very dull edges.
Medium (1000–3000 grit) – Everyday sharpening and edge maintenance.
Fine (3000–8000+ grit) – Refining, polishing, and improving edge finish.

For most users, a quality 1000 grit stone or Whetstone set is an excellent starting point.

Sharpening Overview

This is not a complete sharpening guide, but the basic process is:

Prepare your whetstone according to the manufacturer's instructions.
Secure the stone on a stable, non-slip surface.
Sharpen the knife at the appropriate angle, typically around 15–20 degrees.
Continue until a burr forms along the edge.
Repeat on the opposite side.
Progress through finer grits as required.
Finish on a leather strop if desired.

A detailed sharpening guide and video tutorial is available here--->
https://www.youtube.com/watch?v=pshWLfwhL7U

Handling & Usage Tips

Japanese knives are designed for precision cutting, not brute force.

Proper Cutting Technique

Use smooth slicing or push-cutting motions.
Let the sharp edge do the work rather than forcing the knife through food.
Avoid twisting, prying, hacking, or scraping with the edge.
Never cut bones, frozen food, shellfish, or other hard materials unless the knife is specifically designed for it.

Choosing the Right Cutting Board

The surface you cut on has a major impact on edge retention.

Recommended:

Wood cutting boards
Quality plastic cutting boards

Avoid:

Glass
Marble
Stone
Metal surfaces

Hard surfaces will quickly dull and can damage the fine edge of a Japanese knife.

Safe Knife Handling

Hold the knife securely using either the handle or a pinch grip.
Keep fingers clear of the cutting edge.
Always cut on a stable surface.
Wash knives carefully by hand with the edge facing away from you.
Store knives safely when not in use.

Advanced Care Techniques

Rust Prevention

Carbon steel knives can develop rust if left wet for extended periods.

Wash and dry your knife immediately after use.
Wipe carbon steel blades regularly during use, especially when cutting acidic ingredients.
For long-term storage, apply a light coat of non-rancid food-safe oil to protect the blade.

Many manufacturers recommend oiling after every use. In our experience, thorough cleaning and complete drying is sufficient for most users. Oiling is best reserved for long-term storage or humid environments.

Removing Rust & Stains

A rust eraser is one of the easiest ways to remove:

Surface rust
Patina build-up
Stubborn stains
Minor discolouration

Used correctly, it can quickly restore the appearance of your knife without damaging the blade.

Repairing Chips & Edge Damage

Small chips and edge damage can usually be repaired with a whetstone.

Minor chips can often be removed using a medium grit stone.
Larger chips may require a coarse stone before refining the edge on finer grits.
Work slowly and remove only as much steel as necessary.

If the damage is severe, professional sharpening may be the better option.

Storing Your Knife

Proper storage protects both the edge and the user.

Store your knife where the edge cannot contact other utensils or hard surfaces.

Recommended storage options:

Saya (wooden knife sheath)
Edge guards
Magnetic knife strips
Knife blocks
Knife rolls for transport

Avoid storing Japanese knives loose in a drawer, where the edge can become chipped, damaged, or dull.

With proper care, storage and sharpening, a quality Japanese knife can provide decades of reliable service.

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