all about heat !

How pressure cookers work: These are essentially cooking pots with an air tight lid. As water is heated and turns to vapour, the pressure builds up because the vapour cannot escape. Water usually boils and turns to steam (vapour) at 100 ºC at a pressure of 1 atmosphere (i.e 101 kPa). By increasing the pressure we can see from the phase diagram that the water can be heated to higher temperatures before it enters the vapour region. This means that anything being cooked inside the pot will experience higher temperatures and therefore the cooking time will be less. But will it taste as good? .... more interesting facts about heat ,temperature and phase change>here