The Science of Pressure Cooking

The Evolution:

The Pressure Cooker has evolved since its earlier form made of cast metal, which was invented by the French Scientist Denis Papin in 1689. He publicized it as “A New Digester or Engine, for softening bones, the description of its makes and use in cookery, voyages at sea, confectionary, making of drinks, chemistry, and dying, etc.” Although he had thought it could be helpful for the poor to obtain squeeze out nutrition from bones, the dearness of the earlier models made it a failure.

The later versions, especially Alfred VischerFlex-Seal Speed Cooker in 1930s, gained prominence and slowly the cookware started making its hold in ordinary kitchens. In India it was first manufactured in 1959. Gradually Manufacturers came up with the better versions of Pressure Cooker and its contemporary style is something that can be efficiently operated without any hassle.



The Mechanism:

Maximum people might be aware of the simple physics which make a Pressure Cooker work, but they might not relate it when it is applied in the kitchen. Now, before discussing the detailed mechanism of Pressure Cooking, we must know the built of the same.

A normal Pressure Cooker consists of the following parts –

  • The Vessel or Pot which is the main body
  • A Body handle and Cover handle
  • A helper handle at the front
  • The pressure Regulator or Whistle (known popularly)
  • Vent Pipe
  • Lid or Cover
  • Air Vent/Cover Lock
  • Sealing Ring or Rubber Gasket
  • Overpressure Plug

It is a known fact that water boils at 100 degree Celsius (or 212 degree Fahrenheit) after which water starts producing steam, its gaseous state. If we allow more heat to be exerted on an open vessel, the temperature shall remain same while the intensity, with which the steam is produced, will increase. Now it is here, that the pressure cooker, which is a sealed vessel, differs from the conventional cooking vessels.It seals the steam inside, due to which the pressure inside the pot increases and the liquid is pushed to give rise to the boiling temperature.

The temperature in a Pressure Cooker may rise up to 121 degree Celsius (or around 250 degree Fahrenheit) in a Pressure Cooker. The Pressure Regulator on the lid is indicates the required pressure level. The pressure can be maintained by adjusting or lowering the heat source, since excess pressure gets vented out.

Thus Pressure Cooker does nothing more than creating steam pressure with which raw food is cooked easily. The modern day Pressure Cookers are far more advanced and come loaded with many convenient and safety features, which makes cooking, a smooth experience.