A good aeroplane is one that does not fall out of the sky. A good kitchen knife is one that cuts, and keeps cutting for years.
Both sound too obvious to be worth saying, until you remember that an aeroplane stays up because a great many parts are each quietly doing their job, and you want it to go on doing that indefinitely.
A knife is no different. It is not made good by the metal used alone, or by any one single feature. It comes from a handful of things working together: the geometry of the blade, the steel (and how it has been hardened), the edge it carries, and a handle that suits your hand.
People get a little over-obsessed with steel. It does matter. You can make a very bad knife from good steel, but you cannot make a good one without it. Once you have chosen a sound steel, though, what the maker then does with it is colossally important.
A thick blade in excellent steel still cuts badly. A well shaped blade in ordinary steel cuts well to begin with, then loses its edge sooner than it should. Both halves matter: geometry for the cut, steel and hardening for how long it lasts.
Why the obvious signals mislead
Pick up almost any new knife and it will cut a tomato. It should. It is brand new, and entropy has had no chance to touch it. Sharpness straight out of the box tells you almost nothing, because the cheapest knife in the shop manages it on day one.
Judging a knife by its first cut is like reviewing a book by admiring the paper. Nice cover, crisp pages, the printing done well. None of that tells you whether the book is worth reading.
The only questions that matter about a knife are what it is like after three months, after a year, after ten years. Is the edge still keen? Does it come back with a few passes on a honing steel? Does the handle still sit comfortably in the hand, burnished where your thumb rests? That is where good and bad knives separate, and it is the one thing a quick test on a shop counter cannot show you.
Steel is the other misleading signal. It gets credited and blamed for almost everything. The belief that one knife outcuts another because of its steel only holds if everything else about the two knives is identical: the same maker, the same geometry, the same hardening, the same edge. They never are. Change the geometry or the heat treatment and two blades of the same steel will behave nothing alike. Steel is one ingredient among several, and rarely the one that decides the result.
The things that actually decide it
Four things do most of the work. They are worth knowing in the order that matters, rather than the order a sales page lists them.
Geometry. This is the shape of the blade, and in particular how thin it is just behind the edge. A bad knife pushes what is effectively an inverted pyramid through a carrot, and you feel it wedge and watch bits of veg fly off your chopping board.
A good knife is thin behind the edge and parts the food cleanly. It is the single biggest difference between a knife that feels good and one that does not. We painstakingly CNC mill ours concave, which we have not seen another maker do, out of something close to an obsession with keeping the blade thin behind the edge. How and why is a subject of its own, linked below.
Heat treatment. Steel is only potential until it has been hardened, and how well that is done matters as much as which steel you started with. Done badly, a good steel ends up soft, brittle or inconsistent. Done well, it becomes what it was meant to be.
Our own knives are made from a Swedish stainless, 14C28N, hardened in-house to 60 HRC. The number is not magic. It is where that steel, that hardness and our geometry are chosen to work together. How hardening and tempering actually work is its own article, and one we will come to separately.
The edge. This is about two things, not one: how sharp the edge is, and how long it stays that way. Sharper is not automatically better. Past a certain point you are only polishing the edge thinner, which makes it weaker and shortens its life.
A working kitchen edge wants a little tooth to it, because most kitchen cutting is a small sawing motion. Some knives, mostly in the Japanese tradition, are built around a clean push cut instead. That is a fair choice for certain conditions, but for a domestic or European professional kitchen we would argue, firmly, that it is the wrong one.
Ours are made to rock and chop, so we keep a little bite on the edge rather than chase a polish that would not last the week.
The handle. A good handle disappears. It fits the hand, has no hard corners digging in, and balances the blade so the knife does what your brain tells it without you having to think. But comfort is not only in the handle. A knife disappears in the hand partly because the blade is doing what you asked. If the edge skids, if the blade wedges, if you have to force every cut, you notice the tool no matter how well shaped the handle is. A good blade and a good handle are not separate virtues. They reinforce each other.
Get those four right and you have a good knife. Notice that only one of them is the steel itself, and even that one depends on what happens to it afterwards.
A good knife and the right knife are not the same thing
It is worth separating two questions that often get muddled. There are qualities that make a knife well made in general: sound materials, careful manufacture, good geometry, a properly finished edge. Those are close to universal. Then there is whether a knife is right for you and for what you actually do, which is personal.
A textbook will tell you which knife to reach for. Most of that is worth ignoring.
My mother would have happily prepared a full Sunday lunch for sixteen people with nothing but a paring knife. A young chef often wants a big bold blade for everything. Neither is wrong (my mother was never wrong…)
If a knife is comfortable, if you cut well with it, if it does the job and stays out of your way, then it is the right knife for you, whatever anyone on the internet insists.
It is your knife. You will use it more than anyone else ever will, so it ought to be the one you reach for with pleasure.
People sometimes arrive almost apologetic about the knife they love, as though there were a correct answer they had failed to give. There is not.
A well made knife in a shape you enjoy using will always beat a “correct” knife you find awkward.
How we think about it
It is worth being plain about our own bias. We have made knives for years, but that is not the lens we judge by.
The question we keep returning to is not how we have always made a knife, it is how a knife should be made: what the objective criteria actually are, geometry, balance, steel, hardness, the edge, and how to do each of them as well as it can be done.
We hold nothing sacred in that. If someone produced a steel tomorrow, at the same cost and availability, that gave a real gain in sharpness and edge life, we would change to it without hesitation. A maker defending a choice because it is theirs, rather than because it is right, has stopped asking the only question that matters.
How to tell, without any equipment
You do not need a laboratory to judge a knife. But you do need to be honest about which questions you can answer on a counter, or on a website, and which you cannot.
Some of it you can feel. Pick the knife up: is it comfortable, does it balance, are there hard edges where your hand sits. Make a cut: does the blade part the food or wedge through it. That much is immediate.
The rest you cannot see at all. How well the steel has been hardened, whether the edge will still be good in a year, whether the handle will loosen, none of that shows itself on day one. For those questions you are reading the maker rather than the knife: their record, whether the knives have been tested independently, what guarantee stands behind them, and whether they tell you plainly what the knife is and is not.
One signal is worth more than it looks. A knife hardened to a single, specific figure, sixty on the nose rather than a vague range, is the sign of heat treatment that has been properly controlled, and that is a great deal of trouble to go to. Nobody takes that trouble and then skimps on the geometry or the edge. It would make no sense to. Get the difficult part right and the rest tends to follow.
If you do get to live with a knife, the test is simple. Use it until it starts to drag, then give it a few passes on a honing steel. Does it come back close to new? A month or two later, are you still following that same light routine, with the knife still going where you point it? A knife that passes that is a good one. Most do not.
There is an old idea, borrowed from Terry Pratchett, that explains why this matters for the wallet as well as the kitchen. A cheap pair of boots wears out and is replaced, again and again, until the man who could only ever afford cheap boots has spent more than the man who bought one good pair and kept his feet dry for a decade. Knives are the same.
A block of poor knives bought for the price of two good ones disappoints for years, then needs replacing anyway. It is why people who come in wanting a set of six often leave with two or three. Those are the ones they actually use.
The principle worth keeping
A knife is good when you stop noticing it. The edge goes where you send it, the blade parts the food without fuss, the handle sits quietly in the hand, and it carries on doing all of that for years.
Everything that serves those ends is worth paying for. Everything that does not, the patterned steel, the etching, the thousand years of alleged samurai tradition, is decoration. Flummery. Pleasant enough, and often a quiet distraction from whether the knife is any good underneath.
Be wary of the gimmick sold as the point. A car is not a good car because the wheels are anodised red. They may look very smart, but if that is the headline, it is worth asking what is being kept quiet. The same goes for a knife wrapped in an impressively complicated number to describe its steel. Everything should do its job first and be made handsome afterwards, never the other way round.
Learn to tell the function from the blarney, and you can judge any knife in the world. Including ours.