The Pressure Cooker mechanism is an extensive topic, which has only increased its scope with the advancement in technology. Although it is vessel that is being used since longin kitchens, there are many facts related to them, which are not known to many. The pressure cookers today have many variants. They are differentiated into electric, gas stove and induction base pressure cooker. Again the designs are available in diverse range, which are chosen as per whims or utility. The benefits and disadvantages related to each type vary. The adding of food ingredients and water, cooking, and accessorising the cookware, all involve different approaches. Opening a pressure cooker is also a different matter to be dealt with. This is because, the way and the period within which it is opened, affects the outcome of food that is in the stage of being prepared. The opening method, which works for one type, may not work in case of the other. The lid of a pressure cooker can enable a food to be cooked in different manners, by pressurizing and depressurizing the vessel. Thus, it may be called the most important part of the utensil. The effects of opening a pressure cooker can be described as follows: The natural release of steam from cookers is the oldest technique existing of pressure release. In this process, the vapour is allowed to come out naturally without any intervention. The time taken is around ten minutes in which may extend in case of high fill level or electric cookers being used. This method is ideal for expanding and frothing food items like the fruits, legumes, grains, and for desserts, meats, as well as, stocks. The grains like rice have the ability to cook in residual steam, even after the cooker is removed from heat source. Under the quick or normal releasing technique, the steam is allowed to vent out in a relatively short time. This is done by relieving the cooker of its vent weight or whistle or by giving small jolts to remove remaining steam pockets. This is useful for processes like stewing, in which additions are to be made in between, while preparing a dish. The opening process is also used in quick cooking foods. The duration for this method is around 2-3 minutes. The foaming items like grains and meat, etc. are not suitable to be cooked under this method. Another type of opening method of lid is the slow normal releasing method. This method is quite similar to the above method only differs in the sense that the normal venting out is allowed slowly. Short bursts of steam are ensured using interventions, and the gap between each burst should be kept around 10 seconds. The intervention is closing and opening of valves or vent. The cold water or base immersion techniques that were used with aluminum pressure cookers are no longer advisable. It is because the stainless steel is used more by a pressure cooker manufacturer at present.