<P> Boiling is also often used to remove salt from certain foodstuffs, such as bacon if a less saline product is required . </P> <P> Also known as "boil - in - bag", this involves heating or cooking ready - made foods sealed in a thick plastic bag . The bag containing the food, often frozen, is submerged in boiling water for a prescribed time . The resulting dishes can be prepared with greater convenience as no pots or pans are dirtied in the process . Such meals are available for camping as well as home dining . </P> <P> At any given temperature, all the molecules in a liquid do not have the same kinetic energy . Some high energy particles on the liquid surface may have enough energy to escape the intermolecular forces of attraction of the liquid and become a gas . This is called evaporation . </P> <P> Evaporation only happens on the surface while boiling happens throughout the liquid . When a liquid reaches its boiling point bubbles of gas form in it which rise into the surface and burst into the air . This process is called boiling . If the boiling liquid is heated more strongly the temperature does not rise but it boils more quickly . </P>

To cook a food in the vapor given off by boiling water