De-pressurising a pressure cooker
Pressure cooker pressure release methods
After cooking, there are three ways of releasing the pressure, either quickly or slowly, before the lid can be opened. Recipes for pressure cookers usually state which release method is required at the end of the cooking time for proper results—failure to follow the recommendation results in food that is either undercooked or overcooked.
To avoid opening the pressure cooker too often when cooking vegetables with varying cooking times, those which take longer to cook can be cut into smaller pieces and those which cook faster can be cut into thicker pieces.
Cold water quick release
This method is the fastest way of releasing pressure with portable pressure cookers (unless the manufacturer advises against cold water release). It involves running cold tap water over the pressure cooker, avoiding the steam vent or any other valves. It is most suitable for foods with short cooking times and takes only about 20 seconds for the cooker to cool down enough so that the pressure falls and it can be safely opened. This method is not suitable for electric pressure cookers.
Manual, normal, regular, or automatic release
Sometimes called "Quick Release", but not to be confused with the cold water release, this method involves the evacuation of vapor quickly by lifting (or removing) the valve, pushing a button or turning a dial. It is most suitable for interrupted cooking to add food which cooks faster than what is already in the cooker. For example, since meat takes longer to cook than vegetables, for stews it is necessary to add the vegetables later so that they will cook only for the last few minutes. This release method does not cool down the pressure cooker like the cold water release method. Care must be taken when releasing the steam to avoid scalding injury. This release method is not suitable for foods which foam and froth during cooking, as the hot contents could spray outwards from the pressure being released from the steam vent. This release method takes about two minutes to release the pressure before the lid can be opened.
The natural release method allows the pressure to drop slowly; this is achieved by removing the pressure cooker from the heat source and the pressure lowers without any further action. It takes about 10 to 15 minutes (maybe longer) before all the pressure has gone. This method is recommended for foods which foam and froth during cooking, such as rice or pasta, legumes or for recipes such as steamed puddings with raising agents. The texture and tenderness of meat cooked in a pressure cooker may be improved by using the natural release method. The natural release method finishes cooking foods e.g. potatoes with skins (to keep the skins intact) or recipes which have longer cooking times, because the inside of the pressure cooker stays hot. This method is not recommended for foods which require very short cooking times because the food will be overcooked. If using this release method for foods such as potatoes, the cooking time is reduced compared to the other two release methods; on the other hand, if the natural release method is not used, the cooking time will need to be increased by a few minutes to compensate.