Why Meals Cook Faster In Pressure Cooker??

Pressure cookers are designed to cook foods at higher temperatures so the cooking gets done faster.

A pressure cooker consists of a pot and lid, which are usually made of metals such as aluminum or stainless steel. The lid has a rubber ring to seal off the space between the lid and the pot, a safety valve made of low melting point alloy, a vent to allow steam to escape, and a detachable vent stopper or pressure regulator that sits on top of the vent throughout the cooking process. This pressure regulator generates extra force (pressure) in addition to the atmospheric pressure (1 atm), which allows water inside the pot to boil under a higher pressure and hence at a temperature higher than its normal boiling point (100°C). So, food can be cooked at a higher temperature (usually 125°C for most pressure cookers). Generally, for every 10°C increase, chemical reaction rate doubles.

Besides cooking faster, this method retains more nutrients present in the food than other methods. And did you know that a pressure cooker is often used by mountain climbers? Without it, water boils off before reaching 100ºC because of the lower atmospheric pressure at high altitudes, leaving the food improperly cooked.

All right. As you know, water normally boils at 100°C, so the temperature of water can’t exceed 100°C in an open vessel (like what’s used in conventional cooking). Under normal conditions (1 atmosphere external pressure at sea level), any food in water can’t be cooked at temperatures greater than 100°C. However, the boiling point of water varies with external pressures—water boils at a higher temperature when the external pressure is increased. So the higher pressure inside a pressure cooker lets the water boil at temperatures greater than 100°C. Make sense? When the external pressure is lowered, water boils at a lower temperature.

The advantages of using a pressure cooker besides saving time:

Use less fuel, and there’s better retention of certain nutrients due to less water required and shortened cooking time (up to 70% faster than with conventional cookers). In addition, toxins and microbes can be destroyed more efficiently at greater temperatures. The same logic applies to canning foods and autoclave instruments