Pressure cooker reviews

Advantages
Cooks foods much faster as compared to other methods
Uses less fuel than boiling/steaming the same quantity in an ordinary pan. Template:Fact
Hygienic compared to open cooking in a pot or utensil. The food is cooked above the boiling point of water, killing more germs.
Nutrients of food are better retained in pressure cooking.
Easy to cook in comparison to other modern gadgets.
Pressure cookers can be used in most of food styles, cooking styles, different recipes.
Easy to clean pressure cooker after cooking.
Allows higher quality cooking at high altitudes (see below section).
The pressure cooker pan can be used as an ordinary saucepan for cooking larger quantities of food.
Safety features
Pressure cookers have a reputation as a dangerous method of cooking with the risk of explosion. Early pressure cookers equipped with only a primary safety valve were at risk of explosion if poorly maintained, allowing food residues to contaminate the release valve. Modern pressure cookers typically have two or three independent safety mechanisms, as well as some additional safety features required for UL approval or the equivalent in other countries, such as an interlock to prevent opening the lid while internal pressure exceeds atmospheric pressure.

Modern pressure cookers employ several safety features, such as a lid interlock and a gauge to indicate when the cooker is pressurized. The pressure cannot build up unless the lid is properly closed and locked in place.

A regulator releases steam when the pressure exceeds the designed pressure for the cooker; this usually takes the form of a weighted stopper, commonly called "the rocker," or "vent weight". This weighted stopper is lifted by the steam pressure, allowing excess pressure to escape. There is usually a backup pressure release mechanism (a safety valve of sorts) that may employ any of a number of different techniques to release pressure quickly if the primary pressure release mechanism fails (for example, if food jams the steam discharge path). One such method is in the form of a hole in the lid blocked by a plug of low melting-point alloy. If the internal temperature (and hence pressure) gets too high, the metal plug will melt, resulting in release of pressure. Another technique takes the form of a rubber grommet with a metal insert at the center. At a sufficiently high pressure, the grommet will distort and blow out of its mounting hole, rapidly releasing the pressure. A common safety feature is the design of the gasket, which expands and releases excess pressure downwards between the lid and the pan (if the pressure cooker is heated on a gas burner, this downward release of pressure can be strong enough to extinguish the gas flames). In some pressure cookers, excess pressure forces the pressure indicator above its housing which releases the pressure vertically upwards, to open the lid after this happens, one must allow the pressure cooker to cool down and then push the pressure indicator down before opening the lid in the usual manner.

Use at high altitudes
A pressure cooker is often used by mountain climbers to compensate for the low atmospheric pressure at a very high altitude. Under these circumstances water boils at temperatures significantly below 100 °C and without the use of a pressure cooker, may leave boiled foods undercooked, as described in Charles Darwin's Voyage of the Beagle:

At the place where we slept water necessarily boiled, from the diminished pressure of the atmosphere, at a lower temperature than it does in a less lofty country; the case being the converse of that of a Papin's digester. Hence the potatoes, after remaining for some hours in the boiling water, were nearly as hard as ever. The pot was left on the fire all night, and next morning it was boiled again, but yet the potatoes were not cooked. I found out this, by overhearing my two companions discussing the cause, they had come to the simple conclusion, "that the cursed pot [which was a new one] did not choose to boil potatoes."