Japan ReviewedThere is a white knife in my kitchen. It is a Kyocera ceramic santoku, I have had it for about ten years, and I still reach for it most days.
Search in English for whether a ceramic knife is worth buying and you get the same answer nearly everywhere: very sharp, not an all-rounder, buy it as a second knife to sit beside your steel one. That is correct as far as it goes. But it frames ceramic as a steel knife that loses on toughness.
Japanese shops explain it differently, and after ten years I think their version is the more useful one. Ceramic contains no metal. So it does not tint what you cut, it does not leave a metallic smell on food, and it cannot rust. Sharpness comes up after all of that, not before it.
This is not a comparison of seven knives. It is one knife I own and would recommend.
Who this is not for
- Anyone looking for their only knife — this is a second knife
- Anyone who needs to cut squash or bone-in meat — you cannot, and I will explain why
- Anyone who enjoys sharpening — ceramic cannot be touched with an ordinary whetstone
- Anyone hoping to keep a factory edge forever — Kyocera themselves say sharpening will not restore it
What ten years did to it
The first thing you notice is the weight, or the lack of it. It is about half what a steel knife weighs. Ten years in, I would put that differently than the box does: it is not that the knife is easy to hold, it is that your hand does not get tired. The difference shows up on the day you are working through a bag of onions.
The edge has not gone. The steel knife I bought around the same time has needed sharpening for years now; this one still goes cleanly through vegetables, meat and fish. I have never sharpened it. Not once, in ten years. Kyocera's explanation is that fine ceramic is hard enough that only diamond will cut it, so it barely wears — and that matches what I have actually seen.
It is most obvious with fruit. Apple slices cut with a steel knife start browning quickly; cut with this one, they do not go the same way. That is the no-metal-ions point, and in Japan it is the main reason people give for choosing ceramic at all. The absence of any metallic smell on food is the same property.
And once, I chipped it. I know exactly how. I cut meat that had been frozen solid. That is not a defect in the knife, it is something I did to it. Nothing else in ten years has caused it any trouble.
The white blade has yellowed with age. I have never bleached it. It makes no difference to how the knife cuts or handles, so I have left it alone. Japanese reviewers report that bleaching brings the white back, if that bothers you.
What you cannot cut with it
I looked this up after chipping mine, and Kyocera is admirably specific about it. Do not cut:
- Frozen or partly-thawed food — this is the one that got me
- Hard vegetables such as squash and pumpkin
- Bone-in meat and fish, and shellfish like crab
- Corn on the cob, rice cakes, fruit stones
- And this one is about technique rather than food: chopping where the blade is driven down onto the board, the way you would shred cabbage
That last one I would have avoided if I had known. The impact goes straight into the edge. Dropping it on a hard floor is off-limits for the same reason.
Put the other way round: that is the whole list. Vegetables, fruit, sashimi, boneless chicken — nearly everything I do in a day is inside what this knife is for.
What works
- About half the weight of a steel knife, which matters on long prep
- Ten years on, the edge is still there. I have never sharpened it
- No metal in it, so cut fruit does not brown as fast and food picks up no metallic smell
- Cannot rust. Dishwasher-safe, and kitchen bleach is fine on it
What to know first
- I chipped it on frozen meat. Hard things are genuinely off the menu
- A white blade yellows over the years
- An ordinary whetstone will not sharpen it — it is the electric diamond sharpener or a trip back to the maker
Best for
- Anyone who gets through a lot of vegetables and fruit
- Anyone who finds a heavy knife tiring to hold
- Anyone who already owns a steel knife
Not ideal if
- Anyone who wants one knife to do everything
- Anyone cutting squash, frozen food or bone-in meat regularly
Check it on AmazonRevolution santoku, 5.5in, white blade. The US listing is the white-handled version; the one photographed above is an older Japanese-market model with a black handle, same blade and same shape
Looking after it
Wash it and dry it. It cannot rust, so leaving it wet does not do what it would do to a steel knife. Kyocera list the range as dishwasher-safe and say kitchen bleach is fine.
When the edge does eventually go, you either use Kyocera's electric diamond sharpener or post it back to them — there is a mail-in sharpening service in both Japan and the US. One thing worth knowing before you buy: Kyocera themselves state that because the ceramic is so hard, sharpening will not return the knife to its factory edge.
I have done neither in ten years. For now, that is my answer to the question.
Others in the same range
I have not used any of the following. They are part of the same ceramic range, so they are here in case your kitchen is different from mine.
- Revolution santoku, 5.5in, black blade — the same knife in a different colour. Kyocera's own guidance is that the edge is identical to the white one and the colour is a matter of taste. For anyone who would rather not watch a white blade yellow
- Two-piece set: 5.5in santoku and 4.5in utility knife — the small one is for fruit and peeling, which is where ceramic's advantages show most clearly. A reasonable place to start if you are buying your first one
- Electric diamond sharpener — the only way to sharpen ceramic at home. I would not buy it at the same time as the knife, though. Ten years and I have not needed it
Common questions
Can it be your main knife?
No — that is my conclusion after ten years. If it cannot handle hard food, you need a steel knife as well. This is the second knife on the rack.
How long does it last?
Mine is ten years old and still in service. But that is the result of ten years of not cutting hard things, and the one time I broke that rule, it chipped.
Is it dishwasher safe?
Kyocera say yes, dishwasher and kitchen bleach both. Not dropping it matters more.
Can the yellowing be removed?
Japanese reviewers say bleach brings the white back. I have not tried it. It makes no difference to using the knife.