How to choose a chef's knife

Chef's knives run from about 15cm to 30cm. Shorter blades feel nimble but run out of length on a cabbage or a big onion. Longer blades are fast in a professional kitchen and awkward on a 40cm home board. Somewhere between 20 and 21cm is the sweet spot: long enough to slice through a loaf-sized squash in one stroke, short enough to control on a normal worktop.

If you are used to a small knife, 20cm can look large at first. Give it a week. You will soon get used to it and appreciate how much more it does: it slices a whole onion in fewer strokes and carries chopped veg to the pan in one sweep. If 20cm really feels too much, a 16cm chef's knife is a good place to start; the Season S1 Chef's Knife comes in 16cm (£80) as well as 20cm (£100).

Hardness is measured on the Rockwell C scale (HRC). Traditional German-style knives sit around 56 to 58 HRC: tough and forgiving, but they lose their edge quickly. Japanese-style steels run at 60 HRC and above, so they take a finer edge and keep it far longer. The trade-off is that harder steel is less tolerant of twisting or hacking through bone, and it wants a whetstone rather than a pull-through. For a knife you use daily on vegetables, meat and fish, harder is better.

The edge angle is measured per side. Around 20 degrees is typical of German-style knives; 15 degrees or less is typical of Japanese-style knives. A 15 degree edge glides through a tomato skin rather than pushing against it, and it only works if the steel is hard enough to support it. Hardness and angle go together.

A full tang means the steel runs the whole length of the handle. It gives strength and puts the balance point near the bolster, where your fingers pinch the blade. Hold the knife by the bolster on one finger: if it sits level, the weight is shared between blade and handle and the knife will feel controlled rather than nose-heavy.

Western handles are rounded and fuller, with rivets through a full tang: reassuringly solid and tough. Japanese handles are lighter and more slender, and many people choose them for the traditional look alone. Ask yourself which you would rather pick up every evening: something sturdy and weighty, or something light and quick. Whichever you choose, a pinch grip makes any good knife feel at home in your hand: see how to hold a chef's knife.

The Season S4 Chef's Knife (£100) answers every point above. The 21cm blade is 67-layer Damascus forged around a 10CR steel core hardened to 61 HRC, sharpened to 15 degrees. It has a full tang, a triple-riveted rosewood handle and is balanced at the bolster. Japanese steel and edge angle, Western handle and weight. It comes with a lifetime guarantee and wants hand washing. Knives are sold to over-18s only, with ID shown on delivery.

If you prefer something lighter with a traditional profile, compare it with the S1 in S4 or S1: which Season knife is right for you? Still deciding on blade shape? Read the difference between a chef's knife and a santoku and Japanese or German kitchen knife.