McDonalds burgers have been in the news for surviving food-deteriorating elements better than the rest. Recently, they have raised the bar by surviving a molten copper attack BUT the story does not end here; Leidenfrost effect seems to be the culprit. Read more to find out how.
A YouTuber, Tito4re, performed an experiment by pouring molten copper on Big Mac. Although the temperature difference is huge (Melting point of Copper is 1984*F or 1085*C) the video shows that initially, molten copper bounces off the surface of bun as well as patty. By digging more about such phenomena, we found that it isn’t about the Big Mac rather it is, as the physicist have observed, the Leidenfrost effect.
Leidenfrost effect explains that a liquid does not boil rapidly when it comes in contact with a mass, which is at very high temperature. As soon as the interaction takes place, a protective film of liquid vapors is from around the liquid surface, which keeps liquid from boiling. The same effect is observed while cooking when temperature of a pan is checked by sprinkling water. If the pan is hot enough the droplets skittle around before completely evaporating.
So, how is the Leidenfrost effect working with the Big Mac? When molten copper is poured over the bun, moisture in the bun vaporizes and forms vapor film. After some time when the moisture evaporates completely, copper comes in direct contact with the bun and burns it. Similarly, patty reacts in the same way. Since a major quantity of molten copper was hindered by the vapour film, the rest does very little harm to the bun and even lesser to the patty.
Several experiments have been performed to observe this really cool effect. Dipping wet finger in molten lead and blowing out a mouthful of liquid nitrogen are to name a few. This particular experiment shows that contrary to the conspiracy theories McDonalds burgers are not endowed with immortality. But, fear of losing health takes over the rational observer in us.