A blunt blade crushes what it should be cutting

Why kitchen knives go blunt the way they do

In a kitchen a blade goes blunt not from one event but from the number of repetitions. Over a shift a knife makes thousands of cuts, and each one moves the cutting edge a little. The commonest result is not worn steel but a rolled edge: the edge bends to one side and the knife slides across tomato skin, although under the finger it looks undamaged. Hard plastic boards, ceramic, glass and the habit of sweeping cut produce along the counter with the blade all speed this up. When the blade meets bone, a frozen piece or the bottom of a pan, the result is a chipped edge. Hard Japanese steel does not roll here, it chips: high hardness holds the edge longer but forgives no lateral force. The dishwasher adds its share: heat, harsh detergents and knocking against the rack do more in one cycle than a day of cutting.

What the damage looks like

Turn the knife towards the light and look straight into the cutting edge. Where it shines as a thin white line, the edge is gone: a sharp edge reflects no light. A row of bright dots means small chips, a wavy line a rolled edge. In practice it shows before you see it — the cook presses harder, tomato is crushed rather than parted, herbs blacken because the blade tore them, and what reaches the plate no longer looks as it should.

What sharpening restores, and what it cannot

The bevel is restored to the geometry the maker gave the knife, not to whatever is quickest. A chef’s knife and a santoku are not sharpened like a filleting or boning knife, and a single-bevel Japanese knife carries its bevel on one side only, which is how it must stay. Work runs from coarse to fine grit, at a controlled angle and with cooling, because overheated steel loses its hardness for good and holds no edge again — a fault no later sharpening repairs. The burr is removed and the bevel finished by polishing, since a smooth edge tears less in soft meat and fish skin. Material cannot be given back: a blade ground away to nothing, a cracked bevel and burnt steel are past the point, and you hear that before the work, not after.

How often it is realistically needed

There is no single interval: what decides it is the hours the knife spends in the hand and the surface it works on. A knife in use for the whole shift goes in more often than one used only occasionally, while trueing with a honing steel belongs to every day. The steel creates no sharpness; it only straightens an edge that has rolled during the day. Once trueing no longer lasts to the end of the shift, the knife is ready for sharpening.

A kitchen cannot be without its knives

So do not send everything at once. Split the tools into two or three batches: the worst pieces and the ones you hold in duplicate first, the rest once those are back. That keeps the kitchen working and gives you a comparison: on the board, the difference between a freshly sharpened knife and an untouched one is obvious. Mandoline and slicer blades are taken by prior arrangement, since the machine stands idle until its blade is back.

Before you drop the tools off or post them

Wash the knives, degrease them and wipe them dry. Sheath every blade individually with stiff card folded over the cutting edge or a rigid guard, and never put adhesive tape on the edge itself. Do not send pieces as a bundle, because steel against steel in transit chips edges. Enclose a note with your company name, contact and a list of the contents; for Japanese knives add the make and whether it is single-bevel, since that governs how it is worked. You either drop the tools at the workshop, Ferrarska ulica 14 in Koper, by prior arrangement through +386 51 659 600 · igor.komadina@t-2.net, or post them from Slovenia, Croatia and Italy. There is no collection from your premises and no sharpening in your kitchen.