# Why Does Pressure Cooking Make a Difference? And a Pressure Cooker Guide

> A pressure cooker raises the pressure inside it, so the boiling point of water reaches **120°C** instead of 100°C — and that higher temperature cuts the cooking time to roughly **a quarter**. It also preserves more vitamins, because the cooking time is shorter and there is less water.

**4 min read**

The pressure cooker saves more time than any other tool in the kitchen, and it is also the one people are most afraid of. Understanding how it works takes the fear away and lets you use it with precision.

## The physics, simply put

Water boils at **100°C** at normal atmospheric pressure — and however high you turn the heat, it won’t get any hotter than that, because the extra energy just turns it into steam.

**A pressure cooker traps the steam**, so the pressure inside rises — and the higher the pressure, the higher the boiling point.

At **1 bar** above atmospheric pressure, water boils at **120°C**.

**And 20 extra degrees is no small difference** — the rate of chemical reactions roughly doubles with every 10°C. So cooking becomes 3–4 times faster.

## Why the flavour is different

Under pressure the pot is sealed — so the aromatic compounds **don’t escape with the steam** the way they do in an open pan.

**The result:** a stronger, more concentrated flavour and a richer stock.

**The trade-off:** there is no **browning** — the Maillard reaction needs a dry surface and temperatures above 140°C, and a pressure cooker is a moist environment.

**Hence the rule:** brown the meat and onions **first** with the lid off, then seal the pot and bring it up to pressure.

## Cooking times

These times are counted **from the moment full pressure is reached** (once the valve starts whistling):

  - **Chicken pieces:** 10–12 minutes · **Whole chicken:** 25 minutes.
  - **Meat chunks (shoulder/shank):** 40–45 minutes.
  - **Minced meat:** 10 minutes.
  - **Cow’s feet and mombar (rice-stuffed sausage):** 1 hour.
  - **Soaked fava beans for ful medames:** 25–30 minutes.
  - **Soaked chickpeas:** 20 minutes.
  - **Soaked beans:** 15 minutes.
  - **Lentils:** 8 minutes.
  - **White rice:** 5 minutes · **Brown rice:** 22 minutes.
  - **Diced potatoes:** 5 minutes.
  - **Vegetable soup:** 5–8 minutes.
  - **Bone broth:** 45 minutes (instead of 4 hours).

## Releasing the pressure: quick or natural

This point changes the result, and many people overlook it.

**Natural release** (let the cooker cool down on its own): takes 10–20 minutes, and the food keeps cooking during that time. Suitable for meat, pulses and stock.

**Quick release** (open the valve): immediate, and it stops the cooking. Suitable for vegetables, rice and fish — anything that overcooks quickly.

**Using the wrong one** is a common reason for mushy vegetables or tough meat.

## Safety rules

  - **Never fill it more than two-thirds full** — and only half full for foods that foam (pulses, rice and pasta).
  - **There must be liquid** — at least a cup; the pressure comes from steam.
  - **Clean the valve** before every use — a blockage is the main cause of any accident.
  - **Check the gasket** — a cracked or hardened one leaks and stops the pressure building.
  - **Never force it open** — if the lid won’t open, there is still pressure inside.
  - **Don’t leave it unattended** over high heat.

**Modern pressure cookers** have 3–4 successive safety systems — accidents with them are very rare compared with older models.

## Common mistakes

  - **High heat the whole time** — once it reaches full pressure, turn the heat down to the lowest level that maintains it. High heat wastes gas and burns the bottom.
  - **Not browning first** — it gives a boiled taste with no depth.
  - **Too much liquid** — nothing evaporates under pressure, so use **25–30%** less liquid than in a standard recipe.
  - **Timing from when you light the hob** — the time starts once **full pressure is reached**, not when you put the pot on.
  - **Thickening the sauce inside** — starch and flour stick to the bottom and block the valve. Thicken after releasing the pressure, with the lid off.

## What not to cook under pressure

  - **Pasta** — it foams and blocks the valve (except in dedicated recipes with precise timings).
  - **Anything fried** — oil under pressure is extremely dangerous.
  - **Delicate desserts** and cakes (except in a water bath in a separate container).
  - **Leafy greens** — they turn to mush in seconds.
  - **Thin fish** — for the same reason.

## Electric pressure cookers

The main difference is that they **control the heat automatically**, so there is nothing to keep an eye on, and their pressure is slightly lower than that of stovetop models.

**The result:** their times are about **15–20%** longer than the standard charts.

**Their big advantage:** a built-in browning function, so the whole dish is made in one pot.

## Cleaning and maintenance

  - **The gasket** should be removed and washed after every use — it absorbs smells, so rinse it with vinegar every so often.
  - **The valve** should be taken apart and rinsed under the tap.
  - **A gasket lasts** one to two years — if it becomes hard or cracked, replace it.
  - **Storage:** rest the lid upside down on the pot rather than locking it on — so the gasket isn’t squashed and smells aren’t trapped.

## Altitude makes a difference

Something rarely mentioned: the higher you are above sea level, the lower the atmospheric pressure and the lower the boiling point of water.

In high-altitude cities water can boil at **95°C or lower**, and ordinary cooking takes noticeably longer — pulses in particular take twice as long.

**This is where a pressure cooker becomes far more useful**, because it makes up for that shortfall and brings the temperature back to its normal level or higher.

The general rule: increase the pressure-cooking time by **5% for every 300 metres** above sea level.

## Summary

Pressure raises the boiling point to 120°C, so the cooking time drops to a quarter. Brown first, cut the liquid by 25%, time from full pressure, turn the heat down once it is reached, and use natural release for meat and quick release for vegetables.

## FAQ

### Why is pressure cooking faster?
The cooker traps the steam, so the pressure rises and the boiling point of water reaches 120°C instead of 100°C. Every 10°C roughly doubles the speed of the reactions — so the cooking time drops to a quarter.

### Should I release the steam quickly or wait?
Natural release for meat, pulses and stock — the food keeps cooking as it cools. Quick release for vegetables, rice and fish — anything that overcooks quickly. The wrong choice gives you mushy vegetables or tough meat.

### When do I start timing?
From the moment full pressure is reached — that is, once the valve starts whistling or the indicator rises — not from when you light the hob. Getting up to pressure takes 5–15 minutes on its own, depending on the quantity.

### Why shouldn’t I thicken the sauce inside the cooker?
Starch and flour settle on the bottom and stick, and they can block the valve — the most dangerous thing that can happen in a pressure cooker. Thicken the sauce after releasing the pressure, with the lid off, over normal heat.

---

Source: https://hanakoleah.com/en/article/why-pressure-cooking-makes-a-difference
Edited by: Marwa Mohamed
Last updated: 2026-10-24