Choosing a chef's knife

A chef's knife is the piece of equipment you touch most and think about least. Almost everything that happens on a board — onions, herbs, chicken, butternut, a whole week of dinners — happens with this one knife. Which is why buying a good one is the single highest-return decision in a kitchen, and why the choice deserves more than a glance at a price tag.

The good news is that the decision comes down to four things. Everything else on a product page is detail.

Length: 16cm, 20cm or something between

A 20cm blade is the classic professional length. It slices in one pass rather than sawing, it clears a full board of onion in half the strokes, and once you are used to it, nothing shorter feels adequate. It also needs a board with room and a cook who is comfortable with it.

A 16cm blade is the honest recommendation for most home kitchens. It is easier to control, it suits a smaller board and a smaller hand, and people who buy it tend to actually use it. If you are nervous with knives, start here — you can always add length later.

Steel: hardness against forgiveness

German and Japanese knives sit at two ends of a spectrum. German steel is a little softer. It takes a fine edge, holds it well, and — crucially — it will tolerate being dropped, twisted through a joint, or sharpened by someone who is still learning. Japanese steel is harder. It takes a keener edge and keeps it longer, but it is more brittle: chip it against a bone or a ceramic plate and the repair is a real job.

Neither is better. A first serious knife is usually better in German steel. A second knife, bought by someone who now looks after their edges, is often Japanese.

Weight and balance

A forged knife has a bolster — the thickened collar between blade and handle — and it shifts the balance point towards your hand. Heavier knives do more of the work under their own momentum, which suits rocking cuts and dense vegetables. Lighter, stamped or Japanese-style blades reward speed and precision. Both are legitimate. What matters is that the knife feels neutral in your grip rather than tipping forwards or backwards.

The handle

Hold the knife the way you will actually use it: thumb and forefinger pinched on the blade, remaining fingers wrapped around the handle. If your knuckles hit the board when you cut, the handle is too low. If your grip slides when your hands are wet, the material is wrong for you. This is the only part of the decision that cannot be made from a specification.

What we would tell a friend

• Buy one very good chef's knife rather than a seven-piece block of mediocre ones.
• Add a paring knife second and a serrated bread knife third. That trio covers nearly everything.
• Budget for a sharpener at the same time — an unmaintained expensive knife is worse than a maintained cheap one.
• Never put it in the dishwasher. Wash, dry, put it away.

A knife bought properly is not an annual purchase. It is a thirty-year one.