Coming out of Japan in 1985, modern ceramic knives made a big splash in the world of cutlery and cooking. For the longest time, amateur chefs, home cookers, BBQ pit-masters and enthusiasts all had a…complicated…relationship with their beloved steel knives.
A well-made, balanced and maintained knife wasn’t just a useful tool for slicing brisket, it was a work of art and a friend in the kitchen. To keep that friend happy and productive, however, means keeping it clean, oiled and sharpened to a keen edge.
Then came the ceramics. A lightweight, super sharp, easy to clean and low maintenance knife made from space-age advanced ceramics? Hey, this wasn’t your daddy’s santoku.
The ads basically wrote themselves.
As with most things, between promise and result is a little chasm called reality. Sure, ceramic knives have their uses, at which they really are quite good, but they have their limits and downsides as well. In the end, they were not the wonder tool here to replace your old fashioned steel Zwillings that people may have thought they were.
If you are interested in buying a ceramic knife, or bought one and are wondering how and when the heck you’re going to use it, we’ve created this little guide to help you understand where these cool, high tech knives should fit into your cutlery collection.
What is a Ceramic Knife Made Of, Anyway?
First things first. This isn’t the ceramic plate you made in middle school art class.
A ceramic knife is a knife designed around an advanced ceramic blade. The ceramic itself is usually made mostly from Zirconium Dioxide (ZrO2), also known as Zirconia, with some extra stabilizing elements added in. If you picked up on the world Zirconia, that’s probably because its a pretty useful material used in lots of things you come across. With a little materials engineering magic, Zirconium dioxide can be turned into anything from Cubic Zirconium (the fake diamonds that significant others just love) to dental crowns and fake teeth (which you’ll need when you get confused and give them a ceramic engagement knife).
To make a blade out of this powdery substance, Zirconia is first moulded into the rough outline of a blade. Manufacturers then apply 200 tons of pressure to densely pack it all together into a solid, a process called cold isostatic pressing.
From there the knife is fired and baked (sintered) until it’s hard enough to use and then very carefully sharpened using a diamond dust wheel.
Yeah, that’s right, diamonds – we did say this was all very space agey.
Why are ceramic knives so popular?
Ceramic knives found a lot of popularity in Japan and around the world because they have a lot of advantages to them compared to steel knives. Basically, they were and are still marketed as being really sharp and really easy to maintain for amateur and professional chefs alike.
And, to some degree, it’s true. Ceramic knives do have a lot of advantages:
They’re sharp and stay sharp longer
The knives themselves are pretty sharp by nature. You can, it’s true, hone and sharpen a premium kitchen knife to a similar degree, but ceramic knives are that way right out of the box. Ceramic knives also hold an edge very well, meaning they don’t get dull as quickly and so their owners don’t have to sharpen them or get them sharpened professionally.
They’re won’t rust and are easy to clean
Because they are ceramic and not metal, ceramic knives are chemically inert. That means they won’t rust away, stain or affect the taste of your food. They’re also non-porous, so won’t absorb taste or odors like steel can, and can be rinsed and wiped clean.
They’re pretty cool
Finally, they just give off that high tech, lightweight feel, which is cool all by itself.
What are the disadvantages of ceramic knives?
Unfortunately for those looking for easy answers at their next BBQ cookout or in a small kitchen, ceramic knives are not wonder tools here to replace those expensive steel knives. The disadvantages of ceramic are such that they limit where and how you can use them effectively.
When Hard Isn’t Always a Plus
Ceramic knives usually use zirconium dioxide for their blades and are known for being hard. Like, really hard.
To measure hardness in minerals, like zirconium, scientists use a scale pretty descriptively called the Mohs scale of mineral hardness.
A ceramic knife, depending on make, is usually around 8.5 Mohs.
For reference, a diamond (the hardest substance on earth) is at the top of the scale at 10 Mohs, while a typical steel knife might be somewhere around 5.5-6.
Now that’s pretty hard. We all want a hard knife right?
Well, no. Not always.
One little quirk of science is that when something is really hard, it’s often also really brittle. Sure, a material won’t scratch and deform (hardness), it also won’t bend with pressure, and may break when force is applied to it (brittleness).
That’s why those super-hard diamonds can be cut and shaped into a nice ring that costs you 3 months salary, and it’s also a major drawback to hard ceramic knives in the kitchen.
Yes, very broadly speaking a harder material knife will hold its edge better than a softer material knife.
However, because they’re brittle, ceramic knives can break if twisted or flexed – not that uncommon if you cut through unexpectedly tough foods, like hitting a bone in a piece of meat.
Also, if you drop it off a countertop, it can break. Setting you back the cost of the knife plus some (not so) gentle ribbing from your friends and family.
Fans of ceramic knives (and those that sell them) often like to tell you that these knives will never need sharpening. That’s not exactly true.
While much more resistant to blunting than steel knives, they do eventually become less sharp. Because of their intrinsic hardness you need something harder to reshape it, usually specialized diamond coated sharpeners.
That’s right, diamonds again.
But even if you do have the right sharpening tool, because ceramic knives are so brittle, they’re prone to breaking if too much pressure is applied during sharpening and, as a double whammy, they give very little feedback when sharpening so it’s really easy to press too hard.
So in the end, once a ceramic knife becomes too dull to use, most people simply choose to get a new one, which can be expensive and wasteful.
Ceramic knife blades, being so hard and usually thin, are prone to developing chips. With a regular knife, chips ruin the edge of the knife and interfere with the smoothness of your cut, making a clean slice into a rip and tear situation. With a ceramic knife, you get the added bonus of those chips possibly ending up in your food.
Ceramic vs steel knife – how does ceramic stack up?
So you have your preferred ceramic knife in one browser window and a nice, German or Japanese steel chef knife ready to purchase in another. How do you compare them?
Ceramic knives are very light, generally speaking half the weight of a similarly sized steel kitchen knife.
Being lightweight can mean the knife can maintain balance when cutting easier, and may be easier to hold and maneuver for some people. That said, some people prefer a heavier, well-weighted knife.
As with many things knife related, it’s a preference thing and how they feel in your hand really varies between the knife and you.
Ceramic knives, as mentioned before, are generally harder than even premium, high carbon steel knives. But hard doesn’t always a great knife make.
Sure, hard ceramic knives hold an edge better, but they’re far more brittle and less flexible and therefore can’t be used for as wide a range of purposes.
Ceramic knives are sharp right out of the box, making things easier on you. You can get a similar sharpness in a steel knife if you really work at it, but let’s be honest most people won’t.
That said, it’s really hard to sharpen them so you might need to replace it after a few years, whereas you resharpen a steel knife and people can and do pass them down to future generat
Ceramic knives usually aren’t as large as steel knives. You won’t find many beyond 8”, compared to steel knives, which might make smoothly cutting larger items more challenging.
Does Ceramic Make a Good Meat Knife for my BBQ or Kitchen?
Alright, here’s the million dollar question. You spend all day preparing your world famous BBQ . Hours of preparation, seasoning, smoking, and resting have led to this moment.
It’s time to carve and serve. Do you reach for your brand new ceramic knife?
In our opinion: No. Good god, no.
Frankly, a ceramic knife is the wrong type of knife for most meats you’ll handle in the kitchen or at the BBQ pit.
A ceramic knife does best when you’re slicing things (smooth, straight cuts) where you wouldn’t expect sudden resistance or high density and the possibility of the knife flexing or turning. That limits its usefulness to vegetables, fruit and some boneless meats like poultry and fish.
These knives are not at all great for chopping, prying, filleting/de-boning or carving motions, i.e. many of the motions you’d expect when dealing with meat. These impacts can damage the blade and the knife’s inflexible nature means delicate maneuvering around bones (filleting for example), which may require you to press down and flex the blade, and can actually damage or break your knife.
|Fish/chicken (bone in)
Now, cheese is interesting because you would expect its soft nature to be perfect for a ceramic knife.
For soft cheeses, like feta, brie, ricotta, Roquefort, and gorgonzola that’s probably true, although they have a stronger tendency to stick to the smooth ceramic surface.
People have found that the high density of hard cheeses (e.g. Cheddar, Marble, Provolone, Gouda), can cause sudden flexing when people inevitably press down on them, potentially causing the knife to break. So it’s probably best to use a wire or metal cheese knife to be on the safe side.
|Roquefort, Gorgonzola, Boursault, Boursin, Brie
Buchette, Buffalo, Mozzarella, Camembert, Coeur de Chevre
|Parmigiano-Reggiano, Cheddar, Marble, Provolone, Gouda, Gruyere, Mimolette, Grana Pedano
Well, I bought one. I like it. How do I take care of it?
So you bought a ceramic knife. Ignore the knife purists out there, it’s not a bad thing – they do have a lot of advantages, remember? Out of the box sharpness, easy to maintain, chemically inert, etc.
You just have to take care of them, that’s all.
Ceramic knife care
- Handwash with water and dish soap, wipe clean with damp cloth
- Keep clean
- Store in a sheath or knife block so it doesn’t chip or crack
- Handle carefully, it is quite sharp
- Make sure the tip is protected
- Put it in the dishwasher, it will probably break
- Store unsheathed with other objects, it will get chipped and crack
- Use chipped or cracked knives, unless you want to risk getting injured
- Chop, twist, pry, debone or otherwise apply a lot of force or pressure to the knife
How to store ceramic knives
Because they’re easily chipped you don’t want to chuck this in your knife drawer. Ceramic knives. They should be kept in a sheath or in a knife block where the blade and it’s more delicate tip can be protected from chips and cracks
Cutting boards for ceramic knives
Remember, because of their delicate nature, you should always use a softer cutting board that has some give to it in order to prevent damage:
Say Yes to:
- Wood – best option since normal wood is softer and easy to clean
- plastic (not the greatest idea, little cuts can trap bacteria)
Say No to:
- Metal – Sorry, outdoor bbq kitchen guys
Can you sharpen ceramic knives?
A common question asked about ceramic knives is whether you can sharpen them.
One of the main benefits of ceramic knives is that they are low maintenance as far as upkeep goes (assuming you don’t break them). While they lose their edges far, far less often than steel counterparts they can get duller over time and might need to be sharpened.
The nature of the advanced ceramics used means its a tricky situation. Regular sharpeners won’t cut it (sorry), instead you might use diamond coated ceramic knife sharpeners to get the job done. Diamonds, being harder than the ceramic blade itself, are one of the few things that can reliably sharpen and reshape ceramic blades.
That said, it’s not easy.
In fact, unless you’re really skilled at sharpening and are willing to risk a knife or three, we don’t really recommend it. Ceramic knives are very weak against lateral forces, which means you can’t press against them or flex them at all while grinding them or they will break. So you’re looking at a very slow and careful process.
They are also very smooth, they offer no spring or feedback, and leave no burr- the little bits of waste metal you’d find on a knife edge to indicate it’s been sharpened properly and needs to be turned.
If you really want to sharpen your ceramic knife one day, we’d recommend finding a professional or just buy a new one.
Ceramic knives certainly aren’t as useful as a good, steel knife to the amateur chef or BBQ guy. You shouldn’t use them for most meats and frozen foods, really anything that can cause them to flex and break.
That said, ceramic knives do have their place in cooking. They work really well if you need to effortlessly slice vegetables, fruit or even a small piece of boneless meat. Simply put they’re really easy- they’re sharp out of the box, they stay sharp longer, they won’t rust and they’re easy to clean.
But if you’re prone to dropping stuff in the kitchen – well, probably best to stick with steel.
Steph Acevado Having previously worked as a line chef for almost 5 years, Steph is our go-to expert for all things food and meal prep related and is a self-described knife nerd. When she’s not helping people learn to prepare exquisite dinners at home, she’s probably serving up some hot pockets for her twin boys or jogging with her pup Moose around her house in upstate New York.