Electric Pressure cooker cooking uses trapped steam to create a pressurized environment for cooking food. This combined with heat can greatly reduce the cooking time of many items. Foods such as dried beans, roasted meats, and rice will take significantly less time to cook when pressure-cooked. Some people may recognize the term pressure canning, which uses pressure to preserve food. Although they are similar in process, only equipment specifically marked as pressure canning is safe for food preservation.
Why is it so popular?
Pressure cookers originally existed as stovetop versions that required manual pressure monitoring. The advent of the electric pressure cooker helped simplify the process. They have digital settings and controls, so they are generally easy to use. Fast cooking times and the ability to electronically set time and temperature also add to their consumer appeal. Additionally, cookware is a closed system that helps retain moisture, nutrients, and flavor. Unfortunately, there isn't much scientific research on nutrient retention in pressure cooking. One study did find that pressure cooking retained more vitamin C in broccoli than boiling or steaming.
Also, electric pressure cookers are more energy-efficient than stovetop or oven cooking. They are insulated to prevent energy loss during cooking.