People who love cooking know that pressure cooker is a useful cooking appliance. A pressure cooker makes it easier to cook meals in a short time. Pressure cookers were first used in early years and so far, the electronic pressure cooker has been widely used with its improved functions and features. Today, let’s learn something more about the development, working principle and main features of pressure cookers.
Invention of pressure cooker
The pressure cooker was invented by a French doctor Dannis Papin who was also good at physics. He found a phenomenon occasionally in a trip in the Alps that the water boiled to 100? but things were hard to cook thoroughly. As a physicist, he knew that it was because the air is thin and the pressure is low in high mountains. When he came back, he spent about 6 years to research and invented a kind of a sealed container. As the container was sealed, the vapour couldn’t steam out, so the pressure became higher and higher, thus making it possible to get water with over 100?. Meals can be made within 20 minutes by using this kind of container. He called this pot the “Digester”. Up to now, several generations of pressure cookers have been updated.
How does it work?
About how a pressure cooker works, it is not difficult to understand. It is well-known that the boiling point of water is influenced by pressure. The higher the pressure is, the higher the boiling point will be. Outdoor lovers may experience an occasion that an egg can’t be cooked thoroughly in high mountains or high lands. That is because in those places, the pressure is too low and water can boil without reaching to 100?. You know the pressure pot is a sealed container. When the pot heats up, the water inside the pot produces steam but the steam can’t be sent out into the air, therefore, all steam gathers in the pot and makes the pressure higher than an atmosphere pressure. In this case, water must reach up to over 100 degree to boil. To understand this principle, you only need to know two points, raising the pressure and raising the boiling point. Pressure is raised to make it faster to cook meals and make it easier to cook something tough like meat and bones.
Categories of pressure cookers
In terms of materials, pressure cooker can be divided into two categories, aluminum alloy pressure cooker and stainless steel pressure cooker. According to its using methods, there is also electronic pressure cooker. The three kinds of cookers have their own pros and cons.
Aluminum alloy pressure cooker: it is lightweight and the price is respectively cheaper. The aluminum surface is oxidized so it can be well protected from damaging. It is easy to heat up and easy to cool down by cool water. But it has shorter lifespan and is not suitable for induction cooker.
Stainless steel pressure cooker: it is durable and bearable for high temperature. Compared with aluminum alloy cookers, stainless steel cooker looks more beautiful with more styles. It can be widely used by induction cooker, gas cooker, and electronic stove. Meals are healthier as the stainless steel cookers are not easy to generate chemical reactions. But it is difficult to cool down and is not suitable for decocting herb.
Electronic pressure cooker: different from the above two cookers, electronic pressure cooker can work when connected with power source. It is smarter and more convenient. It works under low pressure, can keep foods warm and the pot inside is removable and easy to be washed. It can stew and cook intelligently and safely. It heat up and keep warm at intervals. If the temperature is too high, it will cut off circuit automatically. But electronic cookers are more expensive and have high carbon emission when cool things for a long time.
Pressure cookers are practical in life. It brings convenience to people by applying scientific principles. There are several categories of pressure cookers for your option. But pressure cooker is not completely safe if you use it improperly. No matter what kind of pressure cooker you choose, use it in a correct way.