As Harold McGee will tell you, controlling heat is one of the most basic challenges a cook faces in the kitchen. We’ve all heard that it’s important to preheat your oven, and heat your skillet before adding ingredients. With regards to preheating a skillet however, I’ve always just sort of put the pan over heat for a couple minutes, added some oil, then added the ingredients. While this approach may work for some things, I learned about a year ago that there is actually a small ideal window of heat that you should be aiming for in order to prevent sticking, optimize browning of your meat, and develop a nice fond on the pan.
With a stainless steel skillet, there is a cool trick that will help you identify this window. Once you learn this, your cutlets for chicken marsala will never stick to the pan and your pan-seared steaks will release easily, preserving that delicious caramelized outer crust. Here’s a quick video from rouxbe.com that demonstrates the trick quite well.
Crazy right? I almost didn’t believe that water would just roll across this searing hot pan without evaporating until I tried it myself. It actually works. Of course, if you have a crappy electric stove like ours, it will be much harder to get the whole pan to the same even heat without the center overheating (try moving the pan around on the heating element). But once you get that magic mercury-like ball of water in your skillet, wipe it up, throw in some oil and quickly add your ingredients (have them ready beforehand as the heat window is small) and voila: no sticking!
As you might imagine, this ideal window of heat has to do with the atoms in the pan moving around and “opening and closing the pores” in the steel (in the words of the video). In this sense, the “pores” almost act like tiny teeth that bite into your meat and cause sticking. At the right temperature, the “pores” are static, and your food doesn’t stick. Here’s another video explaining this process a little more in depth.
Honestly, do your cooking a favor and take a couple minutes playing with water on your (stainless steel) pan. You will feel empowered by having a more objective measure for identifying the ideal temperature window and your meat, and guests, will thank you.
UPDATE (12/13/09): OK, it appears that the explanation above was a bit too unscientific for some (including myself). While the main point of this post was to simply share the water trick, I’ve been trying to find a more scientific explanation. Here’s a bit more info:
The Leidenfrost Effect
The water “hovering” over the stainless steel pan like mercury happens due to the phenomenon known as the Leidenfrost effect. You can read more about it on wikipedia, but the basic idea is this: at a certain temperature known as the Leidenfrost point (roughly around 320˚F for water, but varying with surface and pressure), when the water droplet hits the hot pan, the bottom part of the water vaporizes immediately on contact. The resulting gas actually suspends the water above it and creates a pocket of water vapor that slows further heat transfer between the pan and the water. Thus it evaporates more slowly than it would at lower temperatures. At the proper temperature, a similar effect happens with the food you place in the pan, preventing the food from sticking. Check out this incredible high speed video of the leidenfrost effect from the people at Modernist Cuisine.
Stainless Steel Cookware
The idea of “pores” opening and closing in a heated pan is a description that I’ve heard used for years from many sources, but never quite understood (e.g. “heat your wok to open the pores, then add oil to fill them…”). The word “pore” is kind of a misnomer that lacks scientific accuracy. Stainless steel is known to be relatively non-porous in the strict sense of the word, so perhaps rouxbe uses the word lightly (or more for “intuitive” visualization). In the comments below, Brian Geiger offered the mental model of a wavy microscopic steel surface that expands as it heats and then contracts when it comes into contact with the relatively cooler meat, in essence “biting” down onto the tissue and causing sticking. To help you better visualize these expanding and contracting crevices, I found the following scanning electron micrograph of one of the most common types of steel and finish used in cookware (316-2BA).
Jullien et al. (2002) J Food Engineering, 56, 77-87