How to Pressure-Cook With Steam—and Good-Old Science

(cheerful music)

(steam hissing)

[Narrator] The pressure cooker.

It sounds, well, terrifying.

(steam hissing)

But not only is it a perfectly safe way to cook,

if you're not screwing around,

thanks to the laws of physics,

it's a perfectly speedy way to cook.

Now, typically water boils at a 100 degrees Celsius.

That's as hot as it will get.

(steam hissing)

But in a pressure cooker that limit soars to a 120 degrees.

That means you can cook exponentially faster.

For every five degrees you can bump up the temperature

past a 100, you cut your cooking time in half.

Therefore, if you reach a 120 degrees,

you're cooking 16 times faster than normal.

What's going on here?

Well, of course when water boils, it give off steam.

(steam hissing)

In a pressure cooker, that vapor has nowhere to go.

As the velocity of the molecules in the steam

starts climbing, so too does the temperature of the vapor.

The vapor can escape so it's in constant contact

with the water, which raises the temperature of the liquid.

That's how you boil water

at a 120 degrees Celsius instead of a 100.

It's a wonderful tool for chefs like you

since water molecules in the food

also climb to a 120 degrees.

That gives you the power to tenderize

tough foods, like beans, in a flash.

All that said, please read the directions

for your particular pressure cooker

for your own safety and the safety of your neighbors.

(whistling)