evaporation, right? The principle demonstrated by my test was first observed by Johann Gottlob Leidenfrost, an eighteenth-century German doctor Turns out that if you give a drop of water on a pan enough energy, the steam that it produces will be pressed out so forcefully that it will actually lift the water droplet clear off the surface of the pan Because the water is no longer in direct contact with the pan and is insulated by this layer of steam, the transfer of energy between the pan and the water becomes quite inefficient, so the water takes a long time to evaporate The very center of this skillet is still relatively cool, resulting in water that just bubbles as it sits there The edges, however, are hot enough to induce the Leidenfrost effect, causing the entire blob of water to form a cohesive unit that elevates itself above the surface of the pan Here’s a closer look at a Leidenfrost-ified water droplet: This effect can be very useful in the kitchen as a means for judging how hot a pan is if you don’t own an exceedingly sexy infrared instant-read thermometer like I Drop a bead of water on a pan while heating it If it stays on the surface and evaporates rapidly, your pan is under 350°F or so— a suboptimal temperature for most sautéing and searing If the pan is hot enough for the Leidenfrost effect to kick in, the water will form distinct drops that skid and scoot over the surface of the metal, taking quite a while to evaporate Your pan is hot enough to cook in ... on the surface and evaporates rapidly, your pan is under 350°F or so— a suboptimal temperature for most sautéing and searing If the pan is hot enough for the Leidenfrost effect to kick in, the. ..This effect can be very useful in the kitchen as a means for judging how hot a pan is if you don’t own an exceedingly sexy infrared instant-read thermometer like I Drop a bead of water... If the pan is hot enough for the Leidenfrost effect to kick in, the water will form distinct drops that skid and scoot over the surface of the metal, taking quite a while to evaporate Your pan is hot enough to cook in