What is a pressure cooker?
Before going towards how does pressure cooker works, we should understand what pressure cooker actually is?
A pressure is a simple sealed pot with a very tight sealed lid and safety valves. A sealed pot, with a lot of steam inside the pot, which generates high temperature inside and helps to cook the food very fast.
It can cook 30% faster than normal cooking methods, therefore it is widely used in the kitchen, all over the world. It works on the principle of steam pressure. This principle is explained below in detail.
Important parts of pressure cookers
If we talk about parts of pressure cookers then there are many small parts of pressure cookers that help each other during the cooker process. But there are three major parts of pressure cookers which are discussed below:
1- The Lid
In this part of the electric pressure cooker, valves and most of the safety systems resides.
2- The Base
In this part of the pressure cooker the logic and heating reside.
3- The Inner Pot
In this part all the cooking happens. All the ingredients are placed here in this part.
What is pressure cooking?
Pressure cooking is a process of cooking food at high pressure, employing water within a sealed pot, called a pressure cooker. Pressure cooking normally takes less cooking time than normal cooking methods.
Pressure cookers working principle
A Pressure cooker works on steam pressure. As we all know the Ideal Gas Law and its equation is PV = nRT. This equation is applied for closed systems.
In the case of pressure cookers, we consider this equation as P = T (because pressure cooker is a sealed pot) which means, Pressure is directly proportional to Temperature.
If we will increase Pressure then Temperature inside the closed pot will also be increased and vice versa. So when you heat the cooker, the pressure inside the cooker is increased and the temperature inside the cooker is also increased.
This will continue until it reaches the trigger pressure of the safety valves, about double the psi at sea level. That’s the basic principle of pressure cookers.
When pressure cooker was invented?
A French physicist named, Denis Papin was famous for his studies on steam. He invented steam digester in 1679, in order to reduce the cooking time. It was an airtight cooker that was using the steam pressure principle.
It presented to the Royal Society of London after 2 years in 1681 as a scientific study and later he was elected as a member.
In 1864, Georg Gutbrod from Stuttgart started manufacturing pressure cookers with tinned cost iron. In 1918, Spain made a pressure cooker name olla exprés (express cooking pot), under patent number 71143.
Pressure Cookers Generations
These are earlier pressure cookers ever which are also known as “old-type” pressure cookers. These pressure cookers work with the “jiggler valve”. These cookers were mostly offering cooking only one pressure level. Today most cookers are the variations of first-generation.
These generations cookers work with a spring-loaded valve that is often hidden. Some of these cookers do not release pressure and show indicators with marking for showing pressure level. These cookers release steam only when the pan is opened.
In 1991, the third generation of pressure cookers which is also called “electric pressure cookers”, was prepared. These pressure cookers are made of advance and latest technologies. Most of the electric pressure cookers come with Artificial Intelligence integrated into them.
In these pressure cookers settings are pre-programmed and all cooking processes are controlled through a single touch screen. You can handle overheating, overcooking, cooking time, etc. all things with this single touch digital screen.
Types of pressure cookers according to features
Single-purpose pressure cookers
These types of pressure cookers are designed only to handle a single pressure setting. It may be a second-generation cooker or third-generation cooker which specifically designed for a single pressure setting.
Multipurpose pressure cookers
These cookers come with multiple features and can cook multiple foods. These pressure cookers can handle multiple pressure and temperature settings.
It can work as a slow cooker, rice cooker, steamer, and much more. These cookers are most reliable and buying these pressure cookers can replace many other appliances in your kitchen.
How does a pressure cooker work?
A pressure cooker is just a normal pot but with a tightly sealed lid and safety valves. Pressure cookers work on the principle of “Steam pressure”. Steam pressure principle is a simple Ideal Gas Law which is applicable to closed systems.
We can understand this with the help of the equation of Ideal Gas Law (PV=nRT). Here in this equation, all other things are constant and we only see P = T. As pressure is increased temperature is also increased.
Normal cookers can cook food only at the boiling temperature of water at sea level which is 100 degrees centigrade. In general, when the temperature is increased by 10 degrees centigrade, the rate of reaction of a chemical reaction is doubled.
Now if we increase the pressure by ~15 psi, the boiling water temperature goes up to 121 degrees centigrade, and cooking is reduced by a quarter of the standard time, which is a huge reduction in cooking time.
This is how pressure cookers work on the steam pressure principle. This principle is very simple and easy to understand and makes kitchen life very easier.
What we can cook and not cook with pressure cookers?
After reading the above things now we know the working of pressure cookers which is very easy and simple to understand. But the question is what we can cook with pressure cook?
The answer is you can cook almost every meal in the pressure cooker. But it really depends on the pressure settings of pressure cookers. Some pressure cookers are single purpose and some are multipurpose pressure cookers as discussed above.
Single-purpose pressure cookers have a single type of pressure setting and in this type of pressure cooker we can cook limited meals. We can cook only those foods which really suit the pressure setting of this cooker.
Multi-purpose pressure cookers can cook multiple foods within a single cooker. It comes with multiple pressure setting. We can set pressure according to our being cooked meal. These pressure cookers come to pre-programmed settings.
Best foods to cook
We can cook bunch foods in our pressure cookers but the following foods can be cooked more deliciously in pressure cookers:
Foods not to cook
Following are some foods can be tasteless or even harmful for pressure cookers:
- Frying food
Advantages and disadvantages of pressure cookers?
There are several benefits of using pressure cookers because it is one of the most important appliances in the kitchen. Some of the most important benefits of pressure cookers are given below:
1- Cooks Food Faster
A pressure cooker can cook up to 30% faster than normal cooking methods.
2- Retains More Nutrients
Many foods which we cook in pressure cooker comes with better taste than boiled foods because it maintains more minerals and vitamins.
3- Saves Energy
Because cookers can cook meals faster than normal cooking methods, that’s why it saves up to 75% of energy.
4- Easy to Clean
Washing of pressure cookers is even too easy and many of the pressure cookers are even dishware safe.
5- Freedom of cooking
Third generation pressure cookers are made with advanced automated technologies that allow you “Set it and forget it”. A pressure cooker will manage itself cooking, heating, and all necessary processes with bothering you.
1- Not easy to use
People must learn about how to use pressure cookers before cooking in it. Otherwise, it can be harmful to your kitchen.
2- Special care during the cleaning
When you are cleaning it you must have to take care of the sealing ring.
3- Overcooking is possible
If you are not well aware of how does pressure cooker works, it may cause a meal being soaked or overcooked. Therefore you should learn how to use pressure cooker works.