Hi,

This is a common misconception.

Boiling alone does not cook things, high temperature is what cooks things.

The best example I can think of to remember this is liquid nitrogen - if you've ever seen it poured on milk it will make that milk into ice cream by flash freezing it.

However, if you think about it, while it is doing that, the liquid nitrogen is boiling away!

Because of this, we can conclude that it is the average temperature surrounding food that will cook it, not whether or not it is in boiling liquid.

We just tend to boil water for cooking because that affords us the highest available cooking temperature. Historically, it's also probably a good indicator of a consistent temperature, especially when you do not have a thermometer handy.

Now back to the role of pressure

If we pressurize liquids, we increase their boiling point and allow ourselves to reach a higher temperature without having to change the liquid you use (you don't want to use DMSO to make soup).

When you can access this higher temperature, your food will cook more quickly.

In contrast, at low pressure, your water boils away very quickly and at low T, and as a result you cannot cook things very well (the water might boil away before you get any appreciable cooking done).

Please let me know if this is unclear,

Katt