So, you do a lot of precision slicing and dicing when you’re cooking a storm in the kitchen? Then the ceramic knife is your handy-dandy best friend.
Lightweight, extremely sharp and handy, ceramic knives have been a part of the modern-day kitchen. Do they really live up to the hype that they never dull? Apparently not.
So you will eventually have to sharpen your ceramic knife. But how do you do it? It’s not as difficult as you might think!
Ceramic knives are made of Zirconia (zirconium dioxide) which can be honed into that special extra sharp and precise lightweight kitchen slicing implements.
If you own a ceramic knife, you will attest that slicing, even if done on a daily basis, is great with the lightweight and sharp ceramic blade. However, after a good six months (and some a bit more) they do loose their “cutting edge” and get dull.
The obvious solution is to run to a professional home outfit that offers ceramic knife sharpening. But, is this the only way to bring your ceramic knife up to slicing efficiency? Let’s explore what we are up against.
The Ceramic Edge
Ceramic knives are known to be excellent in slicing in the kitchen. This is because of their high brittleness since they have a hardness index of 9.4 compared to steel which only rates at 6.5.
Alongside with this, they are lighter in weight and thinner. Given this, the only material that is capable of sharpening a ceramic knife would be something with a higher hardness rating.
At this point we discover that diamond, which has a hardness of 10, is not only a girl’s best friend. Diamond, being harder than ceramic knife construction is the ceramic knife’s best friend – in terms of keeping it sharp, that is.
So, shall we bust our jewelry boxes to sharpen our ceramic knives? Fortunately, not!
Sharpening a Ceramic Knife
As we all know, stainless steel knives are sharpened using a soapstone, sharpening tool, or can be sent to a professional.
The same goes with their ceramic counterparts, although the technique may vary slightly. You might hear of sharpening tools, waterstones or abrasives: these have a lesser degree of hardness than our ceramic knife blades.
Should you want to sharpen your ceramic knife at home, what you need to buy is a diamond sharpening stone (or plate). They are a bit pricey but worth the investment.
It consists of tiny dust-like industrial diamonds attached to a metal plate. Like in jewelry, not all diamonds are made the same. These sharpening stones come in two main types:
- Continuous Diamond Surface – the surface has patterned holes on its surface to capture swarf.
- Holed Diamond Surface – unbroken smooth surface where you can glide the instrument you are sharpening and the residue falls to the sides.
Both of these are available in mono-crystalline and poly-crystalline diamonds. Mono-crystalline ones are more highly recommended for their durability.
Nonetheless, you investment in the diamond sharpening stone is worth it if only for its top-notch sharpening performance and durability. You can sharpen steel knives and blades on it as well so it’s a win-win situation. The one that we recommend right now is the Double-Sided Diamond Sharpening Plate by Kalolary (affiliate link).
If you have experience sharpening your stainless-steel knives with a soapstone or carborandum stone, then you’re in luck. With a few minor technique adjustments and practice, you can sharpen your ceramic knife just as well.
Sharpening Your Technique
When brushing your stainless knife against a sharpening stone, you always look for that feeling that it bounces back. They call this in professional terms spring or feedback.
As you push the metal, you feel it bend so you exert pressure to whittle the blade in sharpness. DO NOT DO THIS TO A CERAMIC KNIFE!
Ceramic knives may be very sharp and have a hardness close to diamonds but they are also brittle and breakable. When you push too much on the blade thinking it will bend like malleable metal – it won’t.
It will either crack or break under too much pressure because ceramic simple isn’t a ductile material. In other words, your hands should have precise movements. Here is how to do it:
No Lateral Rule – Never sharpen your ceramic knives laterally like you might do with metallic ones! The force you put on the knife tip may cause it to break. This also compromises the integrity of your knife if you push too hard with the ceramic blade unsupported.
Instead, position the knife with the tip downwards and keep it close to a vertical position when sharpening it.
Dual Hand Support
Use both hands when sharpening a ceramic knife. One holding the knife handle and the other supporting the top part of your ceramic blade. Press down applying consistent light force.
There is no problem which direction you go – choose what is more comfortable for you so that you will not accidentally flex and flip which might cause the ceramic blade to snap or be damaged. Nice, smooth motions will do the trick.
Ceramic Knife Sharpening Tools
If you feel like doing the entire deal of sharpening your ceramic knife on a stone is too onerous, the market has recently come up with ceramic knife sharpening tools. Like the diamond sharpening stone, they come with premium prices.
Should you have a slightly lower price point, consider normal sharpening machines BUT!!! Please purchase their diamond stone add-ons or one with a diamond abrasive setting.
A knife sharpening tool helps you align the blade properly so all you have to worry apply is applying the perfect pressure to sharpen your ceramic knife. This one is a cheap and solid option that we recommend getting (affiliate link)
Ceramic Knife Sharpening Rods
Though sharpening rods are the least favorite of most homemakers, there actually are diamond sharpening rods available in the market, meaning that they would work with a ceramic knife as well.
Extra care must be done when using this option as sharpening rods tend to bang the surface of the blade hard if you are not adept with using them.
Remember, unlike steel knives which are pliable and make that funny sword dueling clink when you swish it against the rod, a ceramic knife must be dealt with low pressure, proper angled motions against the diamond sharpening rod.
So even though this is indeed an option to conisder, the previously recommended ones are much better.
How to extend the life of your ceramic knife
Sharpening your ceramic knife is easy once you know how to do it, but you should still consider some (or all) of the tips below in order to keep them in tip top shape for longer.
- Ceramic knives may be almost hard as a diamond but they are also brittle and lightweight. Take good care not to let these drop as their performance may be sensitive to sudden drops and shocks. Don’t just throw them into the sink after use!
- Keep them away from glass! Always use a wooden or plastic cutting board when slicing and dicing with your ceramic knives. Glass and similar hard surfaces will only dull it faster and even cause them to break.
- Ditch the dishwasher. Always handwash your ceramic knives. Using an organic kitchen cleaner could also be a good choice.
- Frozen and hard food slicing are no-no’s for ceramic knives.
- Keep ceramic knives in their protective sleeves and don’t make them bump and grind with other utensils.
- Use an old blade to practice your sharpening skills before trying it on your most precious ceramic knife.
- When sharpening your ceramic knife, grind or glide it a maximum of 6 times then check the sharpness on a tomato or a piece of paper so you need not overgrind it.
- Always take care when grinding – do it on a surface that it not slippery and at a comfortable height to your favored working position.
As they say, in this world nothing is perfect. Even if the advertising boasts that ceramic knives never get dull, always remember that they do eventually get less than their initial sharpness.
But now, if you need to get them back in shape quickly, you know how to do it. And the tips above will also help you prolong their life and keep them as sharp as they can be for longer.