The cutting edge

Keep your knives in working order

By Helen Rennie

January 11, 2007

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Editor’s note: Helen Rennie wrote the Front Burner column from January to June 2007.

“But we have Wüsthof knives!” protested the hostess when I pulled out my travel knife to slice the onions. I tried to find some tactful excuse for using my knife. “It’s a habit,” I assured her. “Once you get used to the handhold, it’s hard to switch.”

I always feel like a freak bringing my own knives when people ask me to cook. I couldn’t help chuckling when I watched an episode of Julia Child’s “The French Chef,” where she lamented the state of knives in home kitchens and said that she had to bring her own when cooking for friends. Of course, that was in the 1960s. These days, we are much more educated about cooking, right? We’ll settle for nothing but the best and most expensive knives — particularly if we get them as wedding presents. Too bad sharpness isn’t something money can buy.

Knives are like cars. There are flimsy Dodge Neons, reliable Hondas, and flashy Ferraris. When it comes to cars, we are very reasonable. We consult Consumer Reports, we talk to our friends, we think about safety and reliability, and we make sure that our local mechanic will be able to change the car’s oil. But when it comes to knives, we do nothing of the sort — we head straight for the Ferrari.

Who can blame us home cooks? With all the knife propaganda on TV and in kitchen stores, it’s really hard to make sense of it all. That’s why, before we jump into a comparison of Wüsthof and Global, we should go over the basics.

Chef’s knives from Forschner, Henckels, and Tojiro

Any cook needs one good chef’s knife. That’s the one with a big handle and a blade that starts out wide near the handle and gets progressively skinnier until it comes to a point. This is the knife you’ll use for 95 percent of kitchen tasks. Don’t bother with knife sets; you are not getting a deal by buying knives you won’t use. Just get yourself one good chef’s knife.

Chef’s knives come in a variety of blade sizes (knife sizes don’t include the handle). Eight inches is the smallest all-purpose knife you should consider. Keep in mind that smaller knives are not safer or easier to handle. You can always cut small vegetables with a large knife, but not large vegetables with a small knife.

Eight-inch chef’s knives cost anywhere between $15 and $150. If you are more of a Honda than a Ferrari cook, I suggest you get an eight-inch Forschner, which retails for about $25. Forschner knives are commonly used in restaurant kitchens. The plastic handle is not as sleek-looking as Wüsthof’s, but the blade is just as good, and it provides plenty of overhang below the handle. Why is the overhang so useful? You’ll find out when we talk about sharpening.

There is a misconception that a good knife will keep its edge longer. Knives are very fragile creatures; cut up some butternut squash or celery root, and the edge will go out of whack. This happens every day, to every knife. So on a daily basis, knives need a swipe through some edge-straightening device. The traditional device is a “steel” — a long stick made out of steel, though nowadays you can find ones made out of ceramic or diamond.

Teachers in all the knife-skills classes I’ve ever taken and the knife salesmen in the gourmet stores make this part sound trivial: “Just give it a few swipes on both sides at a 20-degree angle, and you’re good!” What they all overestimate is a normal person’s ability to judge a 20-degree angle and maintain it while moving the knife down the steel. What happens if you’re a little off? You’re either creating an edge so fine it will break right off, or eating away your edge and making your knife duller than it was already.

The good news is that there are steel alternatives that will help you keep that 20-degree angle. The cheapest and easiest to use is the Accusharp Knife and Tool Sharpener, which retails for $10. It comes to a V that fits right over your edge and maintains the correct angle. Minimal hand-eye coordination is required.

Accusharp Knife and Tool Sharpener

Hold your knife with its edge up and the tip of the blade hanging off the counter. Swipe the Accusharp over the edge two or three times, and voilà — you’ve got yourself a sharp knife. Accusharp does slowly eat away the knife’s blade, thus shortening your knife’s life; you’ll see the metal shavings on your knife after you use it. But in my opinion, it’s better to have a sharp knife for three years than a useless one for life. And if you bought that Forschner, you’ll have plenty of overhang to shave off.

If you want something a little gentler, try the Chef’s Choice 450 2-Stage Manual Sharpener, which retails for $25. It has little rollers that guide your knife at a 20-degree angle. Although sharpening takes a little longer than with the Accusharp, almost none of your knife blade is taken off.

There’s only one little problem. If you’ve got one of those swanky santoku knives or any of the Japanese brands, like Global or Shun, the standard European knife angle of 20 degrees will not work. Japanese knives, some of them one-sided, are sharpened at angles of 16 to 18 degrees. So it’s back to you and your hand-eye coordination. If you want your Japanese knife to keep that razor-sharp edge you admired in the store, you’d better master that steel.

Chef’s Choice 450

No matter which sharpening device you use, make sure you wash and dry your knife before and after sharpening. Sharpening dirty or wet knives doesn’t work, and you don’t want metal shavings in your food, do you?

Once you get used to working with a sharp knife, you’ll start noticing when your razor-sharp edge is gone, because slicing and dicing will suddenly take a bit more effort. An easy and reliable sharpness test is to slide your knife along a tomato or a peach with no downward pressure; a sharp knife should cut cleanly through the skin. Alternatively, you can hold a piece of paper in the air with one hand (holding it from the top) and cut through the paper from the top down. A sharp knife should make a clean cut.

If you decide not to feed your knife to Accusharp because you prefer the gentler edge-aligning tools, your knife will need a new edge put on about once a year. You’ll know when the right time comes, because the steel or Chef’s Choice 450 just won’t give you that razor-sharp edge anymore. If you are determined to have this knife for the rest of your life, take it to a professional sharpener who uses a wet stone. Otherwise, any hardware store will do the trick with a regrinding machine.

No matter which knife you choose, make sure to treat it with respect. Don’t ever let your knife’s edge touch anything harder than the blade. This means using only plastic or wood cutting boards and never cutting on ceramic, glass, granite, marble, or metal surfaces. Avoid leaving your knife in hazardous situations, such as a sink full of dishes, a dish rack, or a dishwasher, because it may come in contact with other objects. Immediately after using your knife, wash it and dry it by hand. Then store it in a butcher block or on a magnetic strip.

Knife sharpening shouldn’t be a stressful ordeal; it should be a 10-second undertaking producing knives as sharp as those of any professional chef. It’s not the money but the care you put into your knives that makes them sharp.

Culinate columnist Helen Rennie is a food writer (check out her blog) and cooking teacher living in Boston.