A pressure cooker reduces cooking time for food because

A pressure cooker reduces cooking time for food because


3 Answers

Suraj Prasad IIT Patna
askIITians Faculty 286 Points
8 years ago
A pressure cooker doesn't allow for anything (even gases) to escape at any significant amounts (unless the pressure inside gets too high and you hear that whistleing noise).

With heat, the gases inside want to expand, but because they are restricted to the volume of the pressure cooker they can't, so pressure builds up.

In addition, when a liquid, lets say water in this case, is heated under normal pressure its temperature won't go above 100C, because any water molecule that has higher energy leaves the liquid and goes into gas phase.

Now, applying pressure to water, will increase the boiling point (for example from 100C to 110C)
Reason: When any liquid is under higher pressure it is less likely to go in the gaseous phase.

The pressure cooker works with these principles, because usually when you cook water in an open pot, the boiling point of water restricts the temperature to a 100C. A pressure cooker uses the pressure to keep the water in the liquid form even though it is far above the boiling point, and hence the temperature is far above 100C.
Because the pressure build up inside causes higher cooking temperatures thus reducing cooking times.
13 Points
4 years ago
A pressure cooker reduces cooking time ... This is because  increase in the pressure inside the cooker . According to Gay-Lussac's law pressure is directely propotional to temperature . And hence increase in temptrature results in decreasing cooking time..
ankit singh
askIITians Faculty 614 Points
2 years ago

Because under pressure, the heat builds faster and maintains temperature better, so cooking time is reduced. ... The increased pressure inside the cooker increases the boiling point of water above 1000C so more cooking is done before the water actually starts to boil. So ultimately food is cooked faster.

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