It was not until the 19th century that scientists managed to liquefy
gases by cooling them to extreme temperatures.

Nowadays, the usefulness of such processes is undeniable, and it
is now impossible to visit a hospital without coming face-to-face
with a liquid oxygen tank. Liquid nitrogen is also widely used in
this environment to conserve body fluids such as blood or sperm,
in addition to eliminating potentially malignant skin lesions such
as warts.

Chef Heston Blumenthal introduced liquid nitrogen to the world of
molecular gastronomy through Peter Barham, a physics professor
and author of the book “The Science of Cooking.” In the early 2000s,
the chef of the restaurant “Fat Duck” in the United Kingdom served
a foam cryogenized with liquid nitrogen from start to finish in front
of his clients.

One must always exercise great caution when handling liquid
nitrogen. The gas maintained in a liquid state at a temperature of
-321°F (-196°C) tries to escape and evaporate. It must be carefully
carried in containers provided for this purpose, such as Dewar
flasks, double-wall insulated vessels designed for liquefied gases.
Keeping liquid nitrogen in an airtight container would turn it into a
real pressure bomb! Liquid nitrogen can also cause serious cold
burns. In addition, if it is used in a poorly ventilated room, it can
cause asphyxiation. The expression “handle with care” therefore
makes sense!