A Five-Year Plan for Your Knife

Yesterday was about choosing a knife that fits your hand and your cooking. Today is about the years after that — the small habits that keep a blade working long after the honeymoon.

The weekly habit: honing (研ぐ)

A knife doesn't get dull in a straight line. The edge rolls over slightly with use. A few passes on a honing rod (シャープナー) once a week — or after every few hours of cooking — straightens it back. This is not sharpening; it's maintenance. Ten seconds, both sides, light pressure. If you cook once a week, do it before you start. If you cook daily, do it Sunday night.

One warning: ceramic rods are fine for most steel, but a very hard blade (HRC 60+) can chip on a rod. Check the maker's advice. When in doubt, use a leather strop (革砥石（かわとし）) instead — gentler, and hard to do wrong.

Monthly: a touch-up on the stone (砥石)

Once a month, or when tomatoes start to squish instead of slice, take the knife to a whetstone (砥石（といし）). A 1000-grit stone is enough for most home cooks. Five minutes per side, consistent angle, light pressure. You are not trying to remove a lot of metal — you are refreshing the edge. If you're not sure of your angle, the marker trick works: colour the bevel with a marker, take one stroke, and see where the ink comes off. That tells you the true angle.

Yearly: thinning (刃を研ぎ直す)

Every year or two, depending on use, a knife needs thinning (肉厚を薄くする). Sharpening alone slowly thickens the area behind the edge, and the knife starts to wedge in carrots. Thinning means grinding the whole side of the blade on a coarse stone (荒砥石（あらといし）) to bring the geometry back. This is the step most home cooks skip, and it's the one that makes an old knife feel new. It takes longer — twenty to thirty minutes — and it's worth practising on a cheap knife first.

When to send it to a professional (研ぎ師)

Some jobs are best left to a professional sharpener (研ぎ師（とぎし）). Signs: a chip in the edge bigger than a grain of rice, a bent tip, a knife that has been thinned unevenly, or a single-bevel knife (片刃（かたば）) like a yanagiba that needs the back hollow reground. In your city, a good knife shop will often sharpen while you wait for a small fee. Ask before you hand over a carbon steel blade — some shops use machines that are too aggressive.

The five-year shape

Year one: learn your angle, keep a 1000-grit stone, hone weekly. Year two: add a 3000-grit finishing stone if you want a finer edge. Year three: first serious thinning. Year four: replace the handle (柄（え）) if it has shrunk or cracked — many handles are cheap to swap. Year five: by now the knife has lost a few millimetres of height. That's normal. A well-maintained knife can last decades; the steel doesn't expire, but neglect does its work quietly.

The one thing to do next

Put a reminder in your phone for Sunday night: hone. That single habit will do more for your knife than any expensive stone. And if you're in your country and unsure where to start, ask at a local knife shop or a cooking school — most are happy to show you the angle once.

friend, a knife is a tool you keep, not a thing you buy. Treat it like that and it will outlast most of your kitchen.