Originally Posted by
Enthalpic
With high-pressure reaction vessels that is not always true. Exothermic reactions can begin to provide the heat and gaseous products build up.
I've had a pressurized reaction vessel explode... it was exciting.
That sounds like more excitement than I really want.
Are any common cooking reactions actually exothermic enough to raise the temperature of something that's already in the low 100s Celsius? I've never thought about it, but off the top of my head yeast rising is the only thing I can think of making food hotter on its own, and that obviously only happens at much lower temperatures than pressure cookers use.