The Leidenfrost Effect

January 11th, 2011

Experiment, Video

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.

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12 Responses to The Leidenfrost Effect

  1. Wow that’s cool! It’s amaz­ing how strangely water behaves at short time scales. Have you seen or attempted to film the phe­nom­e­non of a water droplet dropped onto the sur­face of water? http://dsc.discovery.com/videos/time-warp-water-droplet.html

    • Hi Scott,

      We have yet to film any water drop videos but we are hop­ing to do that. We also plan on play­ing with vary­ing vis­cos­ity and sub­stances. Hope to show ya soon!

      Cheers,
      Ryan

    • i would like to see the ‘boil­ing’ effect of pour­ing vanilla extract into french toast bat­ter (milk and eggs,)

      and the ‘reverse bub­ble’ effect that some­times hap­pens when pour­ing oil into a con­tainer from a hor­i­zon­tal aspect.

      i’d also like them explained!!

  2. These are really stun­ning images, thanks.

    What is the sur­face that this water is on?

    And what is that white stuff inside the water droplets?

    • The droplets are liq­uid nitro­gen, the white stuff inside is ice flakes from the ladle I was using to cre­ate the drops. We shot the video on black glass.

      Cheers
      Ryan

  3. HD ...please

    • We shot it in HD, but had to crop in because the drops were so small. This was shot with a 200mm nikon 1:1 with a 2x tele­con­verter attached at min­i­mum focus dis­tance. We could prob see enough at HD if we were shoot­ing @ 4-5x but then the DOF issue would be much greater –Ryan

  4. Thank you so much for these amaz­ing videos and blog posts!

    Another spec­tac­u­lar Leidenfrost effect is when one dips their hand in a con­tainer of liq­uid nitro­gen— espe­cially in a clear dewar. There is a video on Youtube called Hand vs. Liquid Nitrogen Remake.

    Another sug­ges­tion could be the fry­ing of Starch (such as Mung Bean) noo­dles. This cre­ates an amaz­ing effect!

    Thank you!

  5. The “par­ti­cles” inside the droplets: ice crys­tals, I presume?

  6. I have no idea how it could be done, but I would love to see how the crust forms on deep fried bat­ter coatings.

  7. Pingback: On beans and hard water | Kayahara

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