Why is cooking quicker in a pressure cooker?!
As the pressure inside the cooker increases, the boiling point of water is raised, hence, the cooking process is quicker.
Vegetables and meat cook
quickly in a pressure
cooker. By Pauline Gill, eHow Contributor Old pressure cookers were sometimes
dangerous. If they exploded, injury was
inevitable. Today, pressure cookers are
safer. They stay locked while the pressure is
releasing, protecting you from harm.
Pressure cookers are a quick way to cook meat and a nutritious way to cook
vegetables. When the liquid boils, steam
builds up, creating pressure. Higher cooking temperatures occur resulting in faster
cooking time with little evaporation. Few
vitamins and minerals escape, so your food
We all know the boiling point of sea water is 100 degrees Celsius. When water temperature reached 100 degrees in the atmosphere, water, take a lot of sharp evaporation heat. And water temperature not as heated rise.Of course one of the food is stable at 100 degrees.And in the pressure cooker, because water vapor can't run away, also cannot take away heat, with heating, pot water will exceed 100 degrees. So pressure cooker cooked quickly.
You must know,although the boiling point temperature rise, but is also higher. Cooked food on the speed and temperature, and boiling point is irrelevant.
At 15PSI, the cooking temp of the water and steam rises to 250deg.F, about 48 degrees hotter. The hotter temp cooks food faster because starches absorb water and gelatinize faster (rice, potatoes, sauces) and connective tissues in meat, which are made of collagen, also break down faster with the heat and water to gelatinize. Stew meats become tender in about 50 minutes at this temp, instead of 2.5+ hours at 212degF (or longer for the lower temps at higher altitudes.).
The pressure itself doesn't directly increase cooking speed. It's the higher temp enabled by the pressure. This can be proven because it's possible to experiment by cooking at 212degF at 15psi by pressuring with air and using a thermostatically controlled heating element to limit the temp instead of letting the water rise to 250deg.F. Food cooked at the same temp takes the same amount of time.
Everything cooks quicker because it is under pressure. It's a lot better than in a slow cooker, etc.