In a previous post, we asked what high-speed kitchen event you would like to see slowed down to human eye speed. Among your responses was a request to see droplets of water sizzling in a pan. Thus, the resulting video reveals just how much is going on during that split second when a drop of water contacts a hot surface.
Most of you have sprinkled water on a very hot griddle or pan and watched in amazement as the water broke into small spheres, skating and gliding around on the surface like tiny ball bearings or droplets of mercury. Instead of flattening out and instantly boiling away as one might expect, the water droplets appear to stay round and behave as though they are somehow hovering over the surface. As it turns out, this is indeed almost exactly what happens.
When a drop of liquid first contacts a surface that is much hotter than water’s boiling point, an extremely thin layer of vapor forms under the drop. This layer of vapor suspends the drop slightly above the surface, creating the hovering effect. The vapor also acts as an insulation layer between the surface and liquid, keeping the liquid from rapidly boiling away. This fascinating occurrence is known as the Leidenfrost effect, named for the 18th-century German doctor and theologian who first described the phenomenon.
Most of you have seen the Leidenfrost effect in real time at home, but the Modernist Cuisine team wanted to take you much closer to the action by slowing things down a bit. For this video compilation, we used a Nikon 200 mm 1:1 lens with a 2x teleconverter. The clip was shot at 3,000 frames per second. Playing it back at the conventional speed of 30 fps has the effect of slowing down the video by a factor of 100. We used liquid nitrogen (which has a boiling point of around -321°F)poured onto a room temperature surface, this creates the same effect as water on a very hot pan. The result is stunning. Please enjoy and keep those suggestions coming!
The Leidenfrost effect slowed down by 100x.