Caring for a carbon steel knife

A new carbon steel knife can seeming a little daunting if you haven’t owned one before. If you own one, then you probably have your own way of looking after it that suits you. However, if you’ve just got your first, or are thinking of buying one, here are a few tips that will help you keep it in the best, serviceable condition.

A little info about carbon steel blades -

Called so because they contain carbon as the primary addition to iron, which is what makes steel. What they generally lack though, are other elements that make them resistant to rust. For example, many knives are labelled as “stainless” which refers to the fact they are made with stainless steel. To make it very simple, this is steel with an addition of chromium, which acts as live barrier to prevent rust and other stains forming on the surface.

Carbon steel can be very simple, or it can be a precise formula or various elements forming a very complex steel. But because it often lacks chromium in favour of other characteristics, it does need some care in order to stop rust forming.

Do’s and don'ts -

Do keep your carbon steel blade dry when not in use, if they get washed and left wet, surface rust will start to form. Although not really harmful to your blade short term, it can leave staining and needs removing before you use your knife again, better to just prevent it in the first place.

Do oil your blade occasionally, especially for long term storage. If you don’t cook often, or only get your nice knives out on special occasions. Then its a good idea to store a carbon steel blade with a very fine coating of oil on it. This prevents moisture in the air or surrounding environment from reaching the surface.

Don’t put your knives in the dishwasher. Carbon, or stainless, its sacrilege. Long exposure to hot water and dishwashing salt will stain, rust and damage your carbon blade. It can also dull the edge, and the heat and water will crack wooden handles and degrade the glues used. Always hand wash and dry. If you throw your knife in the cutlery holder to drain, the edge will make hard contact with other metal, which isn’t good. If you’ve got guests over for dinner, its a good idea to wash your knives before they get a chance to.

Don’t worry if your knife gets submerged in the kitchen sink. At the end of the day, they’re tools you use to make the food you eat, they do need to be clean, and they are made with heavy use in mind. A bit of soapy water wont damage them… however, some knives, especially Japanese knives, have natural wood handles. This means the wood is ‘raw’ and isn’t filled with any nasty resins. Hot soapy water can soak in a and swell the handles, maybe even crack them over time. So again, don’t leave them soaking in there for long. It’s also a good idea to use a food safe wood balsam or similar on them to create a bit of a barrier to this stuff. Don’t forget to reapply it when it wears away!

Sharpening

Over time, you knife will begin to dull and lose its edge. How long this takes is dependant on many factors. Metal quality, the way you use it, what you cut on, and how you store it. Depending on the knife, sharpening can be simple, or incredibly technical.

If you’ve been given an heirloom, handcrafted Japanese kitchen knife… please don’t grind it on your high tech, sharpening machine. If you’ve been given a bulk set of chefs starter knives... go for it.

Knife sharpening is a delicate process, and one that takes time to get good results. Most people will be fine using “fancy” sharpening systems on their standard knives. But as soon as you go into the realm of carbon blades, or handcrafted blades in general, then you need to start looking into whetstones and hand sharpening.. Why?

Carbon blades are often more brittle than out of the box stainless. So the rough sharpening systems or knife steels can often do more damage than good. Also, the metals used often have so much potential as a cutting edge, why not get the most out of your blade?

So what the hell do I use?!

A good quality combination whetstone will do the trick for most knives, a good starting point is 1000/3000 double sided. But don’t bother with anything cheap off of amazon. If you have a knife of exceptional quality or delicate steel (yes, “delicate” steel is a thing and it makes some of the best knives in my opinion), then you need to invest in some high quality stones of varying grits, Often 1000, 2000, 5000, maybe even 10000, and spend some serious time on your cheaper knives learning to sharpen properly. Alternatively, find a reputable sharpener who does whetstone sharpening... (coughcoughArashi Forge). And have them give your knife the care it deserves.

A little tip
To get the most life out of a sharp blade, consider buying a leather strop and even some polishing compound, after every few uses, strop your blade carefully to hone the edge and extend its life before needing a re-sharpen. Also, carefully store your blade to prevent the edge coming into contact with other metal.