Knife Knowledge Basics: Carbon Steel Care

by Kevin Kent June 06, 2016 2 min read 0 Comments

White carbon, blue carbon and super blue carbon steel bring awesomeness to knife making that is unbeatable. Having a hardness that borders on the extreme they are capable of being sharpened to razor-like keenness, and hold an edge for a very long time.


The trade off for this wicked sharpness is oxidation. That means they could rust. Looked after properly, however, they will develop a patina long before any rust can take root.

You will find, as I have, that these blades will change colour becoming grey or even black as they are used. This is just the patina developing. Consider how a copper roof becomes green over time, or a leather jacket becomes more beautiful as it ages. This is an oxidation process that occurs with carbon steel knives, once the patina has developed the surface will no longer be susceptible to further corrosion (rust).

Should rusting occur simply use a kitchen scrubby (not copper or steel wool as this will scratch the surface) and warm, soapy water to remove anything that looks like rust.

It’s impossible to avoid some discoloration with carbon steel knives. I love to watch this develop over time and am rewarded with the keenness of the edge and the longer edge retention that you get with this quality of white or blue carbon steel.

As you use them on foods like onions, tomatoes or other acidic food you will notice that a greyish hue will develop. This is to be expected, just wash with warm water and keep dry. My carbon knives have a strong patina that I acknowledge as a reward for using exceptional knives, each blade being unique.

Kevin Kent
Kevin Kent

Kevin Kent’s fascination with Japanese knives began while he was working as sous-chef for the legendary chef Fergus Henderson at St. John restaurant in London, England. In 2007, he began selling handcrafted Japanese knives out of a backpack on the back of his bicycle, while working as a chef at River Café in Calgary, Canada. Kent is just as obsessed with Japanese knives as when he first held one, and a few times a year, he travels to Japan to meet with his blacksmith friends, to drink far too much sake, and to learn more about the ancient art of knife-making. Born and raised in Saskatchewan, he refuses to confess how many Japanese knives he owns….but he admits the number is rather high. Follow Kevin on Twitter @knifenerd


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