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Sunday, September 29, 2013

Keeping Your Edge

My Arm Is Complete Again Dept.: We looked at chef’s knives in this posting; now let’s consider how to keep them sharp.

                                                                           
                        

THE BLADE DESCENDS to the edge of the tomato and, with little applied pressure, eases through the skin with no resistance, leaving a rich red slice to fall to the cutting board below. It’s one of my defining moments of summer. It requires a superbly sharp knife.

Photo by B. A. Nilsson
I’m sure that your cutlery is beautifully maintained, but that you share my despair whenever you visit a friend’s kitchen and can’t find a chef’s knife with a decent edge. “I keep my knives dull on purpose,” a friend of mine tried to argue. “That way I won’t cut myself.”

In fact, the opposite is true. It’s the dull blade that inflicts damage, because so much more force is required to accomplish anything and so much less control is therefore available. A good, sharp knife does its work with what feels like minimal effort.

To make sense of the challenge of keeping a knife that sharp, we need to look closely – microscopically, even – at the blade. It’s like a saw. Enlarge the edge and you’ll see a row of tiny pointed teeth. Freshly sharpened, those teeth stand upright, ready to grab that tomato skin and, as you give the knife some lateral movement, inflict a clean incision.

But those teeth get hammered over time, losing that nice alignment. Your light-duty sharpening tool is a steel, which is a long metal or ceramic rod with a handle at one end. Its purpose is to realign the knife’s teeth, restoring a good measure of sharpness, and it’s something many chefs do to their tools before the start of a day’s work.

The efficacy of a steel is complicated by the variety of chef’s knives now available – the principal difference being between western- and Japanese-style blades. Japanese knives typically are made with harder metal and are sharpened at a more acute angle, allowing them to achieve the sharpest possible edge and hold that sharpness longer. The drawback is that the harder metal is also more brittle, which is why such knives often are clad with multiple layers of softer metal for protection.
   
A conventional sharpening steel has striated edges that can break tiny chips off of a hard but brittle blade, so a smoother ceramic steel is recommended for use with Japanese knives. But you’ll also find a degree of fanaticism among owners of such knives, who will let nothing but a waterstone touch the blade.

Which introduces the heavy-duty sharpening tools. These are the ones that actually remove metal from the edge, creating a new row of fine, even teeth. Some manner of stone is the simplest and most enduring, but it demands skill. You need to know your grades of grit and sharpening angles.

Waterstones for Japanese knives start with a coarse 300 or so (arato), meant only for reviving a knife that is chipped and dull. You’ll start with a 1,000-grit stone (nakato), which is water-moistened according to its instructions (typically a five-minute soak).

To achieve the ten- to 15-degree angle for the blade face, place two pennies on the stone under the spine of the knife. Give five to seven swipes along the stone. You should feel a burl begin to form. Unless yours is a single-edged knife, flip it and hone the other side. The process is finished with a 6,000-grit stone (shiage).

Dare I say that this is only scratching the surface? A quick web search will uncover far more detailed advice, with passions running high as to every tool and step involved in the process.

Western-style knives are heavier but are made from softer steel, with a blade angle of 20 degrees on each side. Quick edge-restoration solutions include gadgets like the Fiskars sharpener, available online for about $10, which sports a plastic knife guide to bring the edge in contact with a pair of rollers angled to give you a combined edge of 30 degrees. It will give you an edge, but the edge won’t last as long as a fully sharpened one.

This is also the case with the Wusthof two-stage sharpener, which comes in Japanese (15 degree) and western (20 degree) models, for about $15-$20 each. Start with a few passes across the coarse (carbide) blades; finish with a few swipes across the ceramic blades. Again, it’s effective, but seems to fall between a steel and a full-fledged sharpening.

Which brings us to the motorized models. The necessity of maintaining a correct bevel angle has penetrated the sharpening-world consciousness, so that machines like the Chef’s Choice 1520 are available. At about $150, it’s the price of a decent knife, and it features two-stage guides for 15- and 20-degree blades. Draw your knife a few times through the correct guide, alternating left and right, and you’ll feel a sharper edge with a noticeable burl. Pass the knife through the honing stage and the burl is removed and the blade is as sharp as when it was new.

The Chef’s Choice Trizor gives your western knives a double bevel, letting you bring them to 15 degrees per side, which I think is completely unnecessary. If you want to choose the exact angle, there’s an electric Edgeware sharpener (also about $150) that offers a range of ten to 30 degrees each side.

Internet blogs teem with advice and opinions on this subject, especially from the sharpen-by-hand enthusiasts. I used to be one of you. I also used to whip cream by hand in a copper pot and chop meat with a hand-cranked grinder. All of which now allows me to enjoy the benefits of motorization so much more, along with some damn sharp knives.

Metroland Magazine, 25 April 2012

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