Japanese knives are highly sought after by chefs around the globe and are prized for their sharpness and design. While many types of chef knives are made in Japan today, the term “Japanese knife” is generally reserved for high-carbon steel knives closely linked to samurai swords and still often produced by hand.
Knives made of high-carbon steel, more often referred to as "carbon steel", are preferred by professional chefs over stainless-steel blades. They can be sharpened into finer edges, keep an edge much longer, and some say they can even improve the flavor of your food. Unfortunately, those benefits come with a trade-off; carbon-steel knifes are more prone to color change and rust.
As a good chef knife is perhaps the single most important piece of equipment in any kitchen, and a Japanese knife can often be a pricy investment, it is important to learn how to properly care for and maintain a knife so it can help you create magic in the kitchen for years to come.
Guide For Knife Use
Do not cut through bones, frozen foods, coconuts or extremely dense items.
Always cut with a smooth action and never twist the blade. Sideways pressure may cause the blade to fracture or chip.
Don't cut directly on hard surfaces such as a bench-top, stainless steel sink, plate or chopping boards made from glass, ceramic, bamboo, corian and other hard substances. A wooden chopping board or soft plastic chopping board is best.
Remember your knives do have limitations and are not indestructible. Please always use the proper tool for the job, and do not use your knife as a screwdriver, can opener, jimmy, hammer, oyster opener, or chisel.
Guide For Rust Prevention
Build A Patina Early
Carbon steel knives will naturally change color over time—becoming various shades of blue, grey, and even black as they age. This color, called "patina", develops as the carbon steel is exposed to air and acids.
One of the first things you can do to help protect your blade from rust is to force a patina onto the blade. Patinas naturally form when cooking with anything acidic. So you can force one to appear by rubbing your knife with something acidic—instant coffee, vinegar, potatoes, or lemons are all great options.
It's important to keep an eye on the color of your knife. Cool tones like blues, grey, and black are good, but warm tones like oranges and reds can be an early indicator of rust.
Keep Your Blade Dry
A wet knife will become a rusty knife. So it's important to keep your knife dry. This means that it should be dried immediately after washing—not left out to air dry. You also shouldn't be storing your knife in a knife block. Knife blocks retain moisture and don't allow blades to dry 100 percent. They are also breeding grounds for bacteria. A magnetic strip on the wall, or simply just wrapping your knife in cloth or paper and storing it in a drawer are the best ways to store your knife.
Hand Wash Your Knife
Carbon-steel knives should be washed immediately after use with warm soapy water. Do not leave your knife in a sink full of dishes where its blade can get damaged—or worse, damage you. And NEVER PUT YOUR KNIFE IN A DISHWASHER.
Use Mineral Oil
Food-grade mineral oils can help to "seal" your knife and prevent rust. By applying a few drops and rubbing them into the knife with a cotton cloth once a week for the first few months of knife ownership, you can form a rust resistant protective seal.
Refrain from using olive oil, sesame oil, or other fragrant oils to treat your knife as the odors can be absorbed by your knife and can be transferred to other foods.
Remove Rust As Soon As It Appears
If your knife develops rust despite your best efforts, know that it's not the end of the world, as there are many simple methods for rust removal. Products like "rust erasers" or even wine corks and gentle kitchen scrubbies can usually buff the rust off. However, if the rust is more extensive, then "Bar Keepers' Friend", baking soda, or even a fine 1000 grit sandpaper may be used. Just be sure to use a gentle touch as not to scratch the blade and remove the patina that you've developed.
With a little care and attention, a Japanese knife will outlast any stainless steel knives in your collection. It will even start to reflect your own unique style of cooking, and as the Japanese believe, it will hold a little part of you soul.
About the author:
Kimberly Matsuno is a professional content writer and editor from the US. Having spent several years living in the Japanese countryside, Kimberly holds a particular fondness for Japanese culture and cuisine—particularly anything made with shiso. You can view more of her work at kimberlymatsuno.com.