How sharp are ceramic knives?

[Shalmanese]

I've never handled a ceramic knife before and I keep on hearing that they're very sharp but most people think a Wustof is "very sharp".

On the scale of Foschner - Wustof - Shun - Custom $1000 Japanese Magic Knife, how sharp would an off the shelf Kyocera ceramic knife be?

[helenjp]

I would say, compared to a good Japanese knife kept sharp and in good condition, I don't know that a Kyocera knife is hugely sharper. The advantage is more that it's THIN and sharp.

They don't last for ever...the blade will inevitably develop nicks, although I understand it is sometimes possible to get them reground. I also wonder if they get little surface cracks that propagate over time.

A ceramic blade can cope with some fibrous items, but it's not good with hard items. My husband just broke our small Kyocera trying to cut a pumpkin with it. That's the second time he's done that...even though the knife packet practically screams "Do not use on pumpkin/hard items".

[docdix]

they are sharp but I would not use it for cutting when there is a chance of hitting any bone or cartilage.Since it is very hard too, it will not take to bending. I use my kyocera for sashimi or carving tender boneless roasts only. Incidentally, it was only given as a present but I have always had reservations about buying them for my own.

[Dave the Cook]

I keep a couple of Kyocera parers around for cutting citrus for cocktails because they allow me to be lazy about not washing them right away. I also have several Shuns, a couple of Henckels and a Wusthof. My impression is that the ceramics are about as keen as a properly sharpened German-style knife. The thing is, unless you want to pay for time-consuming regrinding (they have to go back to the factory), a ceramic knife is as sharp as it will ever be the day you take it out of the box. After that, it's a long, slow decline. I consider mine disposable; I've had one for a couple of years, and it's about due to be replaced.

[Dakki]

My brother has one and swears by it. It just doesn't feel right in my hand so I'm sticking to steel.

That said, I think you can sharpen them with a diamond stone, and I imagine that paper-thin blade, properly honed, is going to feel sharp as heck.

[tmriga]

These knives have been around for at least 35 years. My father had bought one, for the purpose of filleting fish at Jamaica Bay. He loved using his knife. He bought his in a sporting goods store, not in a kitchen supply. Cabela's carries them, but I do not know much about the ones they carry. They also carry the ceramic honing tool.

If anyone knows about the quality of the Cabela knives, please let me know.

Theresa

[paulraphael]

I would say, compared to a good Japanese knife kept sharp and in good condition, I don't know that a Kyocera knife is hugely sharper. The advantage is more that it's THIN and sharp.

They are actually significantly less sharp than a well sharpened steel knife, and significantly less thin than the thinnest. And there's nothing you can do about it. It's impossible (or at least wildly impractical) to sharpen them and I don't think you could ever thin the blade like you can a steel one.

The advantage is that they hold an edge for a longer, but still very finite time. Then what—send it back to the company once a month? Other disadvantage is that, yeah, it will shatter.

The non-reactivity thing is just smoke. Any decent stainless is non-reactive enough for anything you'll do in the kitchen. If herbs are turning black, that's from a dull knife, not a reactive one. You can prove this by trying an expertly sharpened carbon steel blade.

[Edward J]

I don't own one, I've seen too many broken ones in commercial kitchens.

However I frequently see them at tradeshows and in knife shops and I can't help myself but to try them out.

Many, including the Kyocera are not very sharp at all, and many would not pass my "tomato test", where little or no pressure is used to try and slice a ripe tomato. But what really stuck in my mind is that the majority of them wee hollow ground. I really question the hollow grinding as this makes the edge even more fragile.