How do pressure cookers work?
The principle of pressure cooking is quite simple — and extremely effective. The temperature of water cannot rise above the temperature of boiling, and boiling temperature is dependent on surrounding air pressure. When heat is applied to a pressure cooker, the air pressure and the boiling point inside rise hand-in-hand. This allows cooking temperatures inside your food to rise to higher levels inside than they could otherwise. For example, at sea level (where the pressure is 14.7 lbs per square inch), the boiling point of water is 212° F, the highest temperature that can be reached by water at that elevation. The boiling point is raised 38° (to 250° F) under the additional 15 pounds of pressure that can be obtained in a pressure cooker, and this higher temperature cooks your food much more quickly. A secondary benefit of the increased pressure is that it softens the fibers in food, tenderizing even the toughest of meats and beans. The increased internal temperature and the tenderizing
