The Essential Kitchen: Sharpening Knives
Like changing the batteries in your smoke detector when we re-set our clocks twice a year, or getting a check-up for your birthday, it's a good idea to make knife sharpening a regular habit. It may not be as important as the smoke detector, but it's a household task that can help your cooking be easier -- and safer -- all year long.
Easier? It doesn't matter if you're using a big chef's knife to cube a butternut squash or a small paring knife to trim a piece of fresh ginger, if your knife has an edge you'll be able to work with less effort, more precision, and more speed.
Safer? A dull blade on a smooth surface can slip. Add a little moisture or the distraction of a ringing cell phone and a dull knife is an accident waiting to happen.
When to Sharpen? When to Hone?
Professional chefs and butchers sharpen their knives frequently but most home cooks can get by with once a year. With each sharpening a portion of the blade gets scraped or ground away and after repeated sharpening you'll eventually have to replace the knife. You'll know you're at this point when even professional sharpening doesn't bring back the life of your knife.
Once a knife has been sharpened, with each use its edge gets duller. The pace of dullness will depend upon how often you use the knife as well as the surface you cut against. This is why your choice of cutting board matters: wood and certain polyproprylene and silicone boards are gentle to knives -- gentle as in the impact to the blade with each point of contact; cutting on glass or stone is aggressively harsh.
But just because a blade seems dull doesn't mean it necessarily is. This is because with use, a knife's edge develops microscopic burrs or ragged tears. It's as if an acutely sharp edge rolls over upon itself after being used to cut, slice or chop. But the edge is still sharp -- it's just been misplaced a bit.
To fix this you don't need sharpening; instead you need a honing steel to bring the edge back into alignment.
A honing steel, sometimes sold with a knife set, is a long, slightly abrasive rod on a handle. The rod is made usually out of metal but some are now also made from high density ceramic. By scraping the knife blade along the rod, the tiny burrs get removed and the sharp edge is again in place. Some metal and ceramic rods that have an additional diamond coating actually do some minor sharpening.
How to hone? Simply swipe your knife along the rod, at about a 20-degree angle, with gentle pressure. Remember that you're re-aligning and not sharpening. Swipe the length of the blade from top to bottom -- top to bottom of the blade's edge and top to bottom of the rod. Do this four or five times on each side of the blade. To be safe, swipe the blade away from you, holding both the rod and the blade toward the floor; don't pull the blade toward your face in case your hand slips.
A final point about honing -- do it only on regular blades, NOT serrated blades. Pulling a serrated blade along a honing steel can ruin both the blade and the steel. Serrated knives rarely need sharpening, but when they do, have it professionally done.
You can be amazed how a few rubs of a seemingly dull blade against that honing steel that you never use can bring your knives back to life.
Sharpening Your Own Knives
Sometimes a knife is past simply honing and you need to sharpen it. Home cooks have the same options for knife sharpening as professional chefs, butchers, and fishmongers do -- we can either sharpen our own or have a professional do it for us.
In simplest terms, the way to sharpen a blade is to gently rub it against an abrasive surface, angling the knife at about a 20-degree angle, rubbing one side of the blade and then the other. Some stones use a coating of vegetable oil or water and others are used dry; I don't think there's a difference in results. Your knife store can show you both kinds and also advise you whether a stone can be used interchangeably, meaning with or without the oil or water.
Try to buy your stone at a good knife store where the sales person can show you how to use it. The technique of sharpening with a stone takes a little practice and if you want to see how it's done we've added a link below to a Hulu video that may help.
I have a stone that I use dry and while I improve the edge, I never manage to get the knives as sharp as with a professional sharpening.
I've tried electric sharpeners but never had much luck, although I know cooks who happily use them. One of my problems with the handy electric sharpeners is that they're so easy and quick to use that you may be tempted to treat the sharpener as if it were a honing steel and this is a quick route to ruining your knives.
Professional Knife Sharpening
Many cookware stores offer knife-sharpening services. Almost always you'll need to leave your knives for a day or two and pick them up after they've been sharpened. Prices typically range from $4 to 8 per knife depending upon the size and the condition of your knives. Some stores do the sharpening themselves with an in-house grinding stone, and others send them out to specialists that may use the wet stone method which many say is superior.
Here are cookware stores in both Manhattan and Brooklyn that offer knife sharpening services:
- Broadway Panhandler
- A Cook's Companion
- Sur La Table
- The Brooklyn Kitchen
- Bowery Kitchen Supplies
If you're not in the New York area, check with your favorite local cookware stores and ask about their knife sharpening services.
Knife sharpening experts are an alternative to cookware stores and these professionals also service the knife sharpening needs of restaurants, butchers, and others in the food and garment industries. Here, too, you'll need to do without your knives for a few days but you'll be sure to have the work done by some of the best in the business.
In New York there are two notable companies.
- Henry Westpfal & Co., located at 115 West 25th Street at 6th Avenue, services the diverse needs of the garment industry, barbers and hair stylists, manicurists, and both professional chefs and home cooks. They use a water sharpening method, which they insist is the best way to both protect the knife and get the best result. Prices range from about $4.00 to about $10, depending on the size of the knife and you usually must leave the knives for 48 hours. Because they are a professional, and not retail business, they keep business, not retail hours: open only Monday through Friday, 9:00 a.m. to 6:30 p.m. The last time I had my knives sharpened, I brought them here; a paring knife and two chef knives cost a total of $21.00 and they did a superb job.
- Ambrosi Cutlery, a full-service cutlery family-owned operation located in Hudson Valley, began as a service for restaurants and butcher shops across NYC and later expanded to the home market. They were recently profiled in The New York Times and we've written about them here at The City Cook.
Itinerant Cutlery Grinders
If you live in certain New York neighborhoods, you have a very local and only-in-New York kind of alternative. Calling themselves grinders, these are knife sharpeners who have trucks equipped with all the tools needed (except water) to sharpen knives, scissors and anything else with a blade. Announcing themselves with a bell like an ice cream truck, they pull to the side of the street and look for you to bring your knives which they sharpen while you wait. Prices can be better than that charged by the store-based sharpeners, but talk with your neighbors to first get a review. Schedules seem to be elusive so you'll have to listen for the bell.
- In Manhattan, on the Upper West Side -- Mike's green truck
- In Manhattan and Brooklyn (Brooklyn Heights and Park Slope) -- Dominic Del Re and his red truck
A final point about knives and sharpening. If even with professional care and frequent honing your knives aren't holding their edge or seem to need frequent sharpening, it may be time for new ones. Also, what's the quality of your knives? Stainless blades won't hold an edge for long -- your best choices are ones made from steel.
Buy the best knives you can afford, take care of them, keep them sharp and honed, and you'll be a better, safer, and happier cook.