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Why use a pressure cooker to cook food easily?

Why use a pressure cooker to cook food easily?

Pressure cookers, when boilers are heated, the pressure in the pot is very high. Why in high-pressure conditions is the food in the pot easy to cook?
Under standard atmospheric pressure, the boiling point of water is 100 ° C. Using a conventional pot to cook food; the pot temperature cannot be higher than 100 ° C. When the fire is raised or the cooking time is prolonged, the result can only cause the water from the liquid to turn into gas, which means evaporation. The water temperature cannot exceed 100 ° C. That’s because water molecules at 100 ° C already have enough energy to dislodge the barrier of air molecules that become water vapor. But suppose the pressure of the surrounding air is high. In that case, the water molecule must have higher energy to overcome the airborne “barrier” to enter the air, turning into water vapor. . The energy of a water molecule completely depends on the temperature of the water itself. The higher the temperature, the greater the energy of the water molecule. Therefore, if you want to boil water at a higher boiling point temperature, cook food faster, and increase the pot’s pressure.

On the ground, the object is subjected to an atmospheric pressure of about 101.3 kPa. From the ground going deep into the ground, the depth kept increasing by 1,000 m, following the increasing pressure, the water’s boiling point rose 3 ° C. In a mine at a depth of 300 m, water must reach 101 ° C to boil. If you want to bring water to 200 ° C to boil, the pot’s pressure must reach 1418.2 kPa (14.18 at).

pressure cooker photo
Taking advantage of the above principle, people made a pressure cooker. Its biggest feature is its good sealing performance. When the water reaches 100 ° C and begins to boil, the water molecule does not escape from the pot, causing the pot’s pressure to increase gradually. The rise of barometric pressure leads to an increase in the boiling point. So the cookware in the pot can continue to absorb the heat. So the food is easy to cook. The temperature in a pressure cooker can generally reach 120 ° C or higher. At such a temperature, the starch easily becomes a paste, so that the rice is easily cooked into cooked rice. To prevent the pressure cooker’s pressure from being too big, leading to the explosion, the safety valve is fitted on the lid. When the pot’s pressure exceeds the specified value, a part of the high-pressure steam penetrates the safety valve to escape, thereby making the pot maintain a certain pressure.

Under a low-pressure situation, the boiling point of water will also drop. For example, when boiling water on Mount Everest, the water reaches 73.5 ° C, it begins to boil. At such temperatures, the food is difficult to cook. So in the low-pressure region on the plateau, taking advantage of a pressure cooker to cook food is the most effective way of cooking.





James Smith
I used to look up at the sky when I was a child and wonder what's in those stars. Growing up, when I had the opportunity to contact the source of human knowledge, I had more knowledge about the universe, the natural world, and created laws. Being the founder of Wikiwap is where I can share my understanding of the world around me in a simple way that readers can access knowledge like a child. You and I are parts of the world; life will always be beautiful.


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