Pressure cooking is a popular cooking method that uses steam pressure to cook food quickly. Many people wonder if pressure cooking actually boils food or if it cooks food in a different way. The short answer is that yes, pressure cooking does boil food, but not in the typical way we think of boiling.
How does pressure cooking work?
In traditional boiling, food is submerged in boiling water which allows steam to escape freely from the pot. The boiling point of water decreases as atmospheric pressure decreases. At sea level, the boiling point of water is 212°F (100°C). In pressure cooking, the pot is sealed, so steam cannot escape. As the pot heats up, pressure increases inside it. At 15 psi (pounds per square inch) of pressure, the boiling point of water increases to 250°F (121°C). This higher temperature allows food to cook faster.
When you put food and liquid into a pressure cooker and seal it, the liquid starts to boil, producing steam. With the lid locked on, that steam has nowhere to go, so it pressurizes the cooker. As pressure increases, the boiling point of the liquid also increases. Once the desired pressure is reached, the heat is lowered just enough to maintain it. If the temperature were to keep rising, the pressure would increase to dangerous levels. Food cooks much faster at these high temperatures while locked under pressure.
Does food actually boil in a pressure cooker?
Yes, the food and liquid inside a pressure cooker do reach boiling point. When pressure cooking, water and other cooking liquids boil at temperatures above 212°F (100°C). Most pressure cooker recipes call for cooking at high pressures of 11-15 psi which produce temperatures around 240°F (116°C) or more.
Bringing cooking liquids to a boil is necessary to create the steam that pressurizes the cooker. As the pressure increases inside the sealed pot, the boiling point becomes elevated along with it. Food is suspended in these boiling hot liquids and reaches these high temperatures itself while cooking under pressure.
Signs that pressure cooking boils food:
- Steam releasing when you open the lid – this steam was created by boiling inside
- Bubbling, churning water when cooking is underway
- Pressure regulator jiggling or rocking to release excess steam
- Food is evenly heated and cooked through
Without the high heat from boiling liquids, pressure cooking would not work effectively. The combination of pressure and boiling is what allows food to cook so much faster compared to regular cooking.
Differences from traditional boiling
While the food does reach boiling temperatures, pressure cooking differs from conventional open pot boiling in a few important ways:
The boiling point is higher
Because the pot is sealed, the internal pressure causes the boiling point to rise far above normal. At 15 psi the boiling point is 250°F (121°C) rather than 212°F (100°C).
It cooks faster
The increased heat from higher boiling temperatures speeds up cooking dramatically. Foods that normally take hours to boil become tender in minutes.
Very little liquid is needed
Only about 1-2 cups of water is needed in a pressure cooker rather than several inches of water for boiling foods normally. The pressurized steam penetrates food efficiently.
Nutrients are retained
The accelerated cooking helps retain more vitamins and minerals compared to boiling, which tends to leach nutrients out of food.
Flavors meld together
The pressurized environment mingles and concentrates flavors beautifully.
How do pressure cookers work?
Pressure cookers use a simple but effective mechanic to dramatically speed up cooking times. Here are the key components that allow pressure cooking to work:
The pot
The heavy-duty, airtight pot is essential for trapping steam to build pressure. Electric models have precision sensors to monitor conditions.
The lid
The tight-locking lid keeps steam and pressure from escaping the pot during cooking.
Regulator
The regulator controls pressure by releasing excess steam. This keeps the pressure at a safe level.
Gasket
A rubber gasket makes a tight seal between the lid and pot to prevent leaks.
Valves
Safety valves provide a crucial release if pressure gets dangerously high. Newer models have extra valve locks.
Tips for successful pressure cooking
Following some basic guidelines will help ensure your pressure cooker meals turn out perfectly cooked and delicious every time:
- Use the correct amount of liquid – usually 1-2 cups is sufficient.
- Allow time for pressure to build up before starting cook time.
- Keep the pressure regulator dial at the recommended psi while cooking.
- Release pressure carefully according to recipe instructions.
- Check the gasket seal regularly and keep the vent pipe clear.
- Adjust cooking time and pressure as needed based on altitude.
What foods work best?
While almost any food can be adapted for pressure cooking, some ingredients are particularly well suited to this fast, moist cooking method. Here are some of the top foods to try pressure cooking:
| Food | Benefits |
|---|---|
| Tough cuts of meat | Become fall-off-the-bone tender in a fraction of normal cook time. |
| Ribs | Meat slides right off the bone after only 20-30 minutes. |
| Chili | Complex flavor melds together in just 10-15 minutes. |
| Risotto | No stirring required, cooks perfectly creamy in 6-8 minutes. |
| Stews | Cooks faster while intensifying flavor. |
| Beans (unsoaked) | Go from dried to perfectly cooked in under an hour. |
Conclusion
While pressure cooking uses a very different mechanism than regular open pot boiling, the food does reach typical boiling temperatures and above. This is what allows pressure cookers to drastically reduce cook times. The trapped steam enables water to boil at hotter than normal temperatures, speeding up the cooking process. While pressure cooking does technically boil food, it does so in a unique way under tightly sealed conditions with precise temperature control. This transforms ordinary boiling into a revolutionary cooking method.