How to keep a kitchen knife sharp

Most people who think their knife needs sharpening actually need to hone it. Honing keeps an edge; sharpening makes one. For an ordinary home kitchen knife, a good starting routine is to hone it on a steel about once a week, and to sharpen it on a whetstone or a decent pull-through sharpener about twice a year. Do both properly and the knife stays sharp almost all the time.

Let me explain the difference, then walk you through each job step by step.

Honing and sharpening are different jobs

The edge of a knife is a very thin strip of metal. As you cut, that strip bends slightly out of line, rolling to one side or the other. The knife feels dull, but the metal is still there; it is simply pointing the wrong way.

Honing pushes that bent edge back into line. It removes almost no metal, so you can do it often.

Sharpening grinds away metal to form a fresh edge where the old one has worn round. It removes metal every time, so you do it only when honing no longer brings the knife back.

A simple test tells you which you need. Hold a sheet of printer paper by one corner and slice down through it. If the knife catches or tears, hone it and try again. If it still tears after honing, it is time to sharpen.

Before you start: safe handling

• Work on a stable surface. Put a damp cloth under your cutting board or stone so it cannot slide.
• Keep the blade moving away from your body and your fingers, never toward them.
• Go slowly. Speed adds nothing here except risk.
• Wipe the blade from spine to edge with a cloth, never by running your fingers along it.
• Keep children and pets out of the way, and put the knife down flat rather than handing it to someone mid-job.

How to hone a knife

You need a honing steel, the long rod that often comes in a knife block.

• Stand the steel upright with its tip resting on a folded towel on your board. This is steadier and safer than waving it in the air.
• Hold the knife in your other hand and place the heel of the blade, the part nearest the handle, against the top of the steel.
• Tilt the blade to about 15 to 20 degrees from the steel. A starting guide: 90 degrees is straight out, half of that is 45, and half again is roughly 20.
• Draw the blade down the steel toward the board, sliding the handle back slightly so the whole edge from heel to tip touches the steel in one smooth stroke. The edge travels downward, away from your body and your other hand.
• Repeat on the other side of the blade at the same angle.
• Do 5 to 8 strokes per side, alternating. Light pressure is enough.

Once a week is a fair starting point for a knife used daily. Some cooks hone before every big prep job; that does no harm.

How to sharpen a knife on a whetstone

A combination whetstone with a coarser side and a finer side covers most home needs. A common pairing is about 1000 grit for sharpening and about 6000 grit for finishing.

• Soak the stone in water for 10 to 15 minutes, or until bubbles stop rising, unless the maker says it should be used dry or with oil.
• Set the stone on a damp cloth or a holder, coarse side up, with the long side facing you.
• Hold the knife at the same angle you honed at, about 15 to 20 degrees, with the edge facing away from you.
• With the fingertips of your free hand resting flat on the blade, well back from the edge, push the blade across the stone, edge leading, sweeping from heel to tip as you go.
• Do 10 strokes, then check for a burr: a very fine rough lip of metal along the opposite side of the edge. Feel for it by drawing your thumb gently across the edge from the spine outward, never along it.
• Once you can feel a burr along the whole length, turn the knife over and repeat on the other side.
• Flip the stone to the fine side and repeat with lighter strokes, alternating sides, to polish the edge and remove the burr.
• Rinse and dry the knife, then test it on paper.

Holding a steady angle matters more than the exact angle you choose. Twice a year is a reasonable starting point for most home kitchens; a knife that cuts a lot may need it more often.

If a stone feels like too much, a pull-through sharpener is quicker and easier, though it gives you less control. Follow its instructions, pull gently and evenly, and do not saw back and forth.

Habits that keep an edge longer

• Cut on wood or plastic boards. Glass, stone and ceramic boards dull an edge quickly.
• Wash and dry knives by hand, straight after use. The dishwasher knocks them about.
• Store them in a block, on a magnetic strip or with edge guards, not loose in a drawer.
• Use the spine, not the edge, to scrape food across the board.

A sharp knife is a safer knife. It goes where you aim it, without force, and that is the whole point of the weekly hone.