This method started in 1679 upon the invention of Denis Papin.
He was a scholar working on the effects of steam and how it can be used in different processes both domestic and economic.
His first ever-cooking vessel, which employs capsulating steam to cook food, was called the Steam Digester.
This tool takes advantage of the same principle behind the pressure cookers we use today.
Since then, pressure cooking has been a great solution for people living in places of high altitudes in order to cook food faster.
Pressure Cooking – The Boiling and Pressure
- When we boil water, it’s boiling point is always at 212°F (100° C). That means that even if we turn up the heat, it will never exceed that temperature, it will only make the water evaporate such in the cases of boiling water in open pots.
- And since any food we cook, be it meat or vegetables, contain water, turning up the heat will not lessen cooking time but will only dry out the moist in our food.
- The altitude of the place where we are affects the temperature in boiling water too. In higher altitudes, the pressure above the water is low which means that the water’s boiling point is decreased. So, the temperature or the fire used must be elevated in order to reach 212°F. In the process, water only turns into vapor.
- Since the pressure above the water is low, the water vapor easily escapes. This escaped vapor becomes steam and it does not help shorten cooking time.
So, how does pressure cooking work?
- This cooking method follows this principle: the steam must be trapped to shorten the food preparation to preserve both the pressure and the heat for water to boil faster.
- Cooking using a sealed container such as the pressure cooker allows both the water and the vapor to be in equilibrium maintaining the same temperature.
- Since the cooking vessel is enclosed, the vapor cannot escape and remains inside creating pressure. When this happens, the steam will increase its velocity and temperature that could reach up to 250° F instead of the usual 212°F (this is the water’s boiling point, 100°C).
- This allows the water to boil and food to cook faster. This is because steam has 6 times heat potential. Even though it is twice as hot, this temperature does not distort food.
- Equal pressure produced by the trapped steam on the surface of cool food product works through its center making it tender.
- Pressure cooking also allows transfer of heat to food surfaces not submerged in liquid.
- This method also builds the characteristics of food through the infusion of different flavors and creation of different textures in shorter periods.
- This cooking speed is approximately up to 25% faster than average. This could be expected in areas at 2000 feet above sea level.
- However, cooking time is still increased by 5% against the reduced cooking period every 1000 feet above the 2000 feet foot base as these are high altitude areas. That still makes it about 30% faster than the average cooking time in high altitude places.
Simply put, boiling is not the cause of temperature but is the result of pressure. The heat inside the pressure cooker is higher so food preparation is made faster and moist and flavors are also preserved.
However, when using this method, the vessel must not be filled with food or liquid. The liquid and solid ingredients must occupy only ⅔ of the cooking pot.
This is important so a space can be created for the steam.
But modern pressure cookers are created with safety features that allow us to check the pressure inside the pot and release it if it gets too much.
If you’re thinking of getting into pressure cooking, check out this 6 Questions You Should Ask Before Getting Into Pressure Cooking.