Walmart, Amazon.com and Bed Bath & Beyond sell pressure cookers. These units use pressure to increase the boiling temperature of water and speed cooking. They are available in both electric and stovetop models.
Cooking foods in a pressure cooker allows food to cook in about one-third of the time it requires in other cooking methods. In order to work correctly, the pressure cooker requires some liquid in the bottom of the pot. Most of the time, water is the cooking liquid, but some recipes call for beer, bullion and fruit juices are also options that increase the flavor of the finished meal.
Some pressure cookers include a cooking rack that divides foods. This allows the user to cook several different foods at the same time. Since pressure-cooking only requires a small amount of water, the flavors do not mingle. Large pressure cookers, otherwise known as canners, use pressure and heat to kill pathogens in preserving foods.
Pressure cookers use a weight to allow steam pressure to build in the vessel. The lid includes a silicon or rubber gasket to prevent the steam from escaping. As the cooker reaches the cooking pressure, the weight begins to jiggle, allowing some steam to escape to prevent too much pressure from building in the pan.