How Does a Pressure Cooker Work?
Modern-day pressure cooking can take the place of several appliances in today's kitchen. That saves money and space! But what is probably the nicest feature of a cooking under pressure is the time savings. By using a pressure cooker in the place of conventional cooking methods can reduce the cooking time of some very healthy and wholesome meals by up to 70%!
But how does cooking under pressure work? And how and why does pressure cook food in the first place?
When you use a pressure cooker, the first step is to place the food in the bottom of the pressure cooker bottom. The bottom is really nothing more than a heavy-duty pot. You can tell the difference between a regular sauce pot and a pressure cooker pot because the latter will have notches along the edge while a standard sauce pan or pot will have a smooth rim surface.
These notches match similar groves in the pressure lid. Typically, once you have the food in place, you are instructed by the recipe or the operating directions that come with the pressure cooking device to add a certain amount of liquid to the pot. It is this liquid that makes a pressure cooker work.
Once the food and the liquid are in the pressure cooker, the lid is fastened to the base, usually by mounting at a 30-50 degree angle away from the handle and then rotating the lid into a locked position. The lid has a gasket that forms an airtight seal between the top and the bottom of the cooker.
As you begin to heat the pressure pot, the liquid inside begins to get hot and approach a boil, steam is created. With the airtight seal in place, the steam has nowhere to escape to and it is this steam generation and retention that makes pressure cooking work.
The amount of pressure is measured in pounds of pressure per square inch, also known as PSI. Typical pressure cooker recipes are mostly cooked at a high degree of pressure. At this pressure, the temperature inside the cooker reaches around 250 degrees Fahrenheit which is almost 40 degrees hotter than the boiling point of foods cooked the traditional way.
But is cooking at that high temperature and with that much pressure safe? Yes! But cooking with pressure still has somewhat of an 'explosive' reputation that lingers like any other 'urban legend' that contains mayhem, violence and bloody gore.
These stories are just not true. Well, let me say that I cannot find any documented evidence of one of these devices exploding since the pre-1960's. And even the stories you find almost all have a central theme in common - user error or safety override!
These devices are well engineered and safe. Used in accordance with the manufacturer's directions and a hint of common sense, modern day pressure cookers work well, last a long time and do NOT blow up!
What can we do with pressure cooking? We tackle this question in another in this series of pressure cooking articles.
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