The Biggest Mistake You're Making With Your Kitchen Knives

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Of all the reasons why someone might collect a large number of knives, being a cook is by far the least troubling. It's often said in culinary school that a knife should be an extension of the chef's hand, so it only stands to reason that you'd want to use that extension as well as it can possibly be used. But not everyone knows how to handle their knives, even if they spring for a fancy Ginsu or Wüsthoff. We talked to Scott Heimendinger, creator of the Quantified Knife Project and founder of Seattle Ultrasonics, and he told us one of the biggest mistakes people make with their kitchen knives is not keeping them sharp.

"Dull knives are dangerous," Heimendinger said, bluntly (no pun intended). It may seem strange that a sharp knife is safer than a dull one — samurai probably don't say, "Watch out for a dull sword" — but it's less a matter of sharpness and more a matter of control. 

"Cutting with a dull knife requires more force to cleave through foods," said Heimendinger. "A dull knife also has less 'bite' than a sharp knife does, so when you're trying to slice into a tomato skin, the edge of the blade is more likely to slide off the tomato." If you're lucky, the knife will slide off the tomato onto your cutting board; if you're unlucky, you'll learn that there's no such thing as a "dull" knife as far as your fingers are concerned.

So, how often should you sharpen your knives to avoid quenching the blade with your blood? According to Scott Heimendinger, it depends on what kind of cook you are. "If you're an occasional home cook, send your knives out for professional sharpening once a year ... " he said. "If you're an enthusiastic home cook, you should probably sharpen your knives at least as often as you deep-clean your cooktop: three to six times per year, or more if you're Iron Cheffing it up." You could invest in a home sharpening kit, or perhaps you're content with making use of a professional service; either way, you could definitely stand to sharpen your knives more often.

But don't be too hard on yourself — you're asking the right questions. "If you sharpen your knives at all, you're already ahead of the curve," Heimendinger said. There is no knife that's immune to going dull, unfortunately, and if you're not careful, you'll end up accepting an inferior experience simply because you've gotten used to it. Just make sure not to use that nifty-sounding aluminum foil hack for knife sharpening, and you're on the right track to getting your cutlery in order.