A bit of household science in the New York Times this week has wrecked my decades-old reverence for the cast-iron skillet. That's according to data from the kitchen of Harold McGee, the great foodie-chemist and author of On Food and Cooking - a book that's nearly as important to your kitchen as a decent chef's knife.
McGee decided to settle a question that I thought I knew the answer to: In pans, what material handles heat best? He tested five skillets ranging in price from trusty $25 cast iron, through various mid-range varieties of aluminum, on up to a steel-coated copper pan that topped $400.
Now, I've always felt a kind of earthy piety when cooking with my trusty cast-iron skillet, which is going on 15 years old. Whether it's delicately crisping a grilled cheese or setting off the smoke detectors over blackened salmon, I've always congratulated myself for sticking with its old-fashioned, even-heating perfection in the face of modern nonstickiness, metallurgical trickery, and charming pastel enamels.
So imagine my surprise. McGee's "point and shoot" thermometer (forget new pans, I want one of those) indicated the cast iron pan was 100 degrees cooler at its edges than in the center. Pretty much every other pan design heated more evenly (and most more quickly) than cast iron. At first I didn't want to believe, but the accompanying photos of toasted parchment were devastating.
Along the way, McGee discovered why butter does a better job than oil at keeping food from sticking, and turned up a principle called Bénard-Margoni convection to explain the ripples that appear in hot oil and look like the "legs" in wine running down a glass.
Three of McGee's skillets had nonstick coatings - something I've sworn off. They're a Catch-22 of annoyances: First, food always sticks to nonstick coatings. And second, you have to spend the rest of the evening waving a limp plastic scrubby at the problem for fear of further damaging the coating that doesn't work in the first place. (Sure enough, McGee saw nicks appear in the nonstick armor of two pans during his experiments.)
Which leaves my only remaining point of pride with cast iron: When you do hopelessly burn a quesadilla, frittata, or korma into the bottom of your pan, you can at least attack it with steel wool and elbow grease.