Talking kitchen knives with Kenji López-Alt

We recently invited Kenji López-Alt, chief creative officer of Serious Eats, whose weekly column The Food Lab explores the science of home cooking, to test a pair of Consumer Reports-recommended knife sets from Henckels and Ginsu. During the video shoot in López-Alt's studio (watch the video below), we also asked him about knives in general. Here's what López-Alt had to say.

Where do you shop for knives?
Most of my knives are custom-made. I find them at flea markets and antique shops. I do also keep some branded knives on hand. The one of I probably use most is a Misono Santoku knife. It’s a Japanese knife made with Swedish stainless steel. I also have a couple Global knives, the ones with the all-metal construction and dimpled grips.

How do Japanese knives differ from Western ones?
Japanese knives have a flatter blade that’s better for chopping. Western knives have a wedge shape blade conducive to rocking and slicing. The Santoku is a modern Japanese knife that combines elements of traditional vegetable, meat, and fish knives. It's meant to handle all types of food relatively well. Most Santokus also have a Granton edge, with little air pockets on the side of the blade that keep foods from sticking.

Do you buy knives individually or by the set?
I only use two or three knives on a regular basis so a set doesn't appeal to me. I'd rather spend $75 on a high-quality chef's knife than get more knives of lesser quality. Once you become adept with a chef's knife, it will do most of what you need. Plus I like to pick and choose my equipment from different brands, since the company that makes the best chef knife or Santoku probably doesn't make the best bread knife or pair of kitchen shears.

What kind of metal do you look for in a knife?
I like carbon steel the most. A lot of knives are made out of stainless steel, meaning the steel has been forged with aluminum, chrome, or some other metal. That prevents rusting and pitting, but it also makes for a hard, brittle blade. Carbon steel is softer, allowing for a super-fine edge, though the blade will need to be sharpened more often.

How do you know when it’s time to sharpen knives?
I can feel the blades getting dull. There’s also the newspaper test, whereby you check the blade’s sharpness by cutting through a sheet of newspaper. An onion is another good test. If a blade is dull, it will slip off the onion before biting into it. The average home cook only needs to sharpen his or her knives once a year. I do it more frequently, especially my chef’s knife, but I’m using it all day every day.

What other maintenance is required to make knives last?
You need to hone the blade. The honing steel doesn't actually take any material off the blade—it simply realigns it. So it's fine to hone before each use. As for cleaning, never put knives in the dishwasher, where their blades could get nicked or chipped. I always wash my knives by hand, then dry them right away before returning them to storage.

Any final thoughts on choosing the perfect knife?
Knives are extremely personal, so you really have to go to a store and see how they feel. Most high-end cutlery stores will put out cutting boards for you to chop on. Remember, the best knife is the one that feels right in your hand.

You have a new book coming out early next year. Can you tell us about it?
It will be similar in spirit to my column, The Food Lab, which is all about food science for home cooks. I like challenging myths and preconceptions of cooking, for example the belief that you shouldn't poke a steak with a fork while cooking it. The amount of juice you lose from poking is negligible compared with other aspects of cooking—for example, overcooking the meat by a quarter degree will lose a lot more moisture. So the book has a lot of science and experiments, along with about 350 recipes.

—Interview by Daniel DiClerico