Nepedia
Back to Discover
Advanced Reader
💻

Pressure cooker

technology Maturity 7-9 Next article →

A pressure cooker is a sealed vessel used to cook food with high-pressure steam.

Pressure cooker
Pressure cooker

This device uses water or other water-based liquids to cook items much faster than conventional boiling. By trapping steam, the cooker increases the internal pressure within the pot. This high pressure prevents boiling at the usual temperature and allows the liquid to reach much higher temperatures. Because of this, food can be cooked in as little as one-quarter of the time required by normal boiling methods. This process is also highly efficient and saves a considerable amount of energy during cooking.

The mechanism of pressure cooking relies on the relationship between pressure and temperature.

Dampfdruckkurve
Dampfdruckkurve

In a normal pot, once water reaches its boiling point, excess heat simply turns the water into steam that escapes. This keeps the water at a steady 100 degrees Celsius. However, a pressure cooker expels air and then traps the steam produced by the boiling liquid. As the steam is trapped, the internal pressure rises. According to the ideal gas law, this increase in pressure raises the boiling point of the water. The water becomes superheated, often reaching temperatures around 120 degrees Celsius. This hot steam transfers heat to the food very efficiently through a process called latent heat of vaporization.

Pressure cooker oval lid
Pressure cooker oval lid

This rapid heat transfer allows the food to reach cooking temperatures much faster than an oven would.

There are three distinct generations of pressure cookers. The first generation, also called "old type" cookers, uses a weight-modified valve known as a "jiggler." This valve releases excess pressure by rattling during operation. These models often have only one pressure level. The second generation uses a spring-loaded valve, which is often hidden inside a mechanism. These cookers frequently offer two or more pressure settings. Some second-generation models are "non-venting," meaning they do not release steam during cooking. Instead, they use a rising indicator to show the pressure level.

WMF Schnelldrucktopf 4,5 Liter Perfect Ultra retouched
WMF Schnelldrucktopf 4,5 Liter Perfect Ultra retouched

The third generation consists of electric pressure cookers, which arrived in 1991. These devices use an electric heat source and digital controllers to regulate temperature and pressure automatically.

The history of the pressure cooker began in the seventeenth century. In 1679, the French physicist Denis Papin invented the steam digester.

Pressure cooker manufactured by Georg Gutbrod, Stuttgart, about 1864
Pressure cooker manufactured by Georg Gutbrod, Stuttgart, about 1864

He intended the device to reduce food cooking times. Papin presented his invention to the Royal Society of London in 1681. Later, in 1864, Georg Gutbrod of Stuttgart began manufacturing cookers made of tinned cast iron. While the concept was old, the specific term "pressure cooker" only became common in the early 20th century. In 1910, Zeno E. Crook founded The Pressure Cooker Company in Denver, Colorado. He developed an aluminum version that was very useful for high-altitude cooking. In 1918, the magazine Popular Science Monthly noted that this was not a new invention, but a rediscovered one.

Pressure cookers are especially significant for cooking at high altitudes. At high elevations, the atmospheric pressure is much lower. This causes the boiling point of water to drop by about 1 degree Celsius for every 294 meters of altitude. For example, on the summit of Mount Everest, water boils at only 71 degrees Celsius. This temperature is often too low to cook many vegetables effectively. Using a pressure cooker helps compensate for this low pressure. It allows cooks to reach the higher temperatures necessary for proper cooking. In these environments, cooking times might otherwise need to increase by 5% for every 1,000 meters of elevation.

Modern devices include many multifunctional options known as multicookers. These can act as slow cookers, rice cookers, yogurt makers, or even steamers. Some recent models, like the Ninja Foodi, are also air fryer pressure cookers. These specialized machines use two separate lids to allow for both pressure cooking and air frying.

Pressure cooker
Pressure cooker

While pressure cooking is very fast, it does not always achieve the high temperatures needed for the Maillard reaction. This reaction is what causes browning and deep flavors during roasting or frying. Because of this, many cooks prefer to sear their food in a pan before placing it in the pressure cooker.

Safety is a major focus in the design of modern pressure cookers. Early fears of explosions led to a decline in household ownership. In 1950, 37% of U.S. households owned a pressure cooker, but by 2011, that number dropped to 20%. This decline was partly due to the popularity of microwave ovens and fears regarding safety. However, third-generation cookers have addressed these concerns with many new features. They include digital temperature control and safety locks that prevent the vessel from opening while under pressure. These improvements have helped make pressure cooking popular once again.

775 words

Where will your curiosity go next?

Keep exploring at your chosen reading level.

🖼️ Images & Media (8)
File:Pressure cooker.jpg
Pressure cooker.jpg
File:Pressure cooker manufactured by Georg Gutbrod, Stuttgart, about 1864.jpg
Pressure cooker manufactured by Georg...
File:Super Cocotte decor SEB-MGR Lyon-IMG 9918.jpg
Super Cocotte decor SEB-MGR Lyon-IMG 9918.jpg
File:WMF Schnelldrucktopf 4,5 Liter Perfect Ultra retouched.jpg
WMF Schnelldrucktopf 4,5 Liter Perfect...
File:Instant Pot DUO60 pressure cooker.jpg
Instant Pot DUO60 pressure cooker.jpg
File:Dampfdruckkurve.svg
Dampfdruckkurve.svg
File:Pressure cooker oval lid.jpg
Pressure cooker oval lid.jpg
File:Aluminum pressure cooker kazan from Afghanistan.jpg
Aluminum pressure cooker kazan from...
More to explore

🔬 Go deeper

More advanced topics to explore

🪜 Step back

Simpler topics to build understanding

What is Nepedia?

A free, ad-free encyclopedia for children. Every article is written at five reading levels, so the same page works for a five-year-old and a fifteen-year-old — use the level switcher above to see this one change. No account needed to read.