A pressure cooker is a sealed pot that builds up steam pressure to cook food faster. The increased pressure raises the boiling point of water, allowing food to cook at higher temperatures and dramatically reducing cooking time.
What is a Pressure Cooker?
A pressure cooker is a thick pot with a locking lid that seals and traps steam inside. As the pot heats up, the liquid inside forms steam which has nowhere to escape. The steam builds pressure against the lid, reaching up to 15 PSI (pounds per square inch) in some models. This pressurized environment allows food to cook faster.
How Does Pressure Cooking Work?
In normal cooking, water boils at 212°F. In a sealed pressure cooker, the boiling point of water is increased due to the added pressure. At 15 PSI, water boils at 250°F to 257°F. This higher temperature cooks food faster by speeding up molecule movement and energy transfer. Food cooks up to 70% faster in a pressure cooker compared to standard boiling.
Advantages of Pressure Cooking
- Saves time – Entire meals can be cooked 3-10 times faster than normal cooking.
- Retains moisture – The sealed environment traps steam and moisture, keeping food tender and juicy.
- Enhances flavor – Pressure cooking draws out flavors from spices, herbs, meats, etc. Foods have rich, concentrated taste.
- Nutrient retention – Cooking at high heat for a shorter time preserves more vitamins and nutrients compared to slower methods.
- Versatile – Can be used to cook rice, beans, meat, poultry, seafood, vegetables, desserts, and more.
- Energy efficient – Requires less time and heat than stovetop or oven cooking.
How Does a Pressure Cooker Build Pressure?
To start pressure cooking, the pot is sealed shut and heat is applied. Liquid inside the pot (water, broth, sauce, etc.) begins to boil, creating steam. As heating continues, steam fills the pot and internal pressure rises.
The trapped steam has nowhere to escape due to the airtight seal. As more steam is produced, pressure continues building until it reaches the desired PSI based on the recipe and pressure cooker model.
At this point, valves indicate pressure has been achieved. The heat source is lowered to maintain this pressurized state and cook the food inside.
Key Pressure Cooker Safety Mechanisms
Modern pressure cookers have built-in safety features to prevent accidents:
- Pressure regulator – Controls and maintains precise pressure levels. If pressure exceeds safe limits, the regulator will release excess steam.
- Locking mechanisms – Keep the lid securely sealed while under pressure. The lid cannot be opened until internal pressure safely drops.
- Pressure release valves – Provide a controlled way to vent steam before opening the lid. Types include quick release and natural release valves.
- Safety fuse – If the regulator fails, the fuse will melt to release pressure and prevent dangerous pressure buildup.
- Backup pressure disc – If both regulator and fuse fail, the backup disc will rupture to let steam escape.
- Additional lid locks – Prevent the lid from being opened if internal pressure is still high after cooking.
Using a Pressure Cooker Safely
To safely use a pressure cooker:
- Read the instruction manual thoroughly and follow manufacturer guidelines.
- Ensure all pressure releasing valves and safety features are working properly before use.
- Use appropriate liquid to create steam and do not let the pot run dry.
- Allow pressure to drop naturally before attempting to open the lid.
- Open lid away from yourself to avoid escaping steam burns.
- Ensure the pot is properly sealed before bringing up to pressure.
- Don’t exceed maximum fill lines for food and liquid.
- Consult a pressure cooker cookbook or recipe designed for pressurized cooking.
With proper operation, a pressure cooker is a safe, convenient way to cook food faster while preserving nutrients and flavors. Understand how it builds pressure and follow safety precautions for best results.