I care about gas saving and for that I want to cook with the lid covering the pot. This allows me to reduce the fire power of the stove top (then using less gas).
I need to cook foods in cooking pots such as rice, noodle, etc. Everyone that cooks these foods know they tend to overflow and (also look at this for the why) if the lid is over, except if the fire is really low, (wich is indeed a possible solution to my problem, but read below).
Idea 1: Is there some ingredient (like salt) that reduces a lot the bubbles that overflow and doesn't affect compromise the food?
Idea 2 (I want this one): Is there a device that releases the pressure automatically when the pot is trying to overflow?
Edit clarification: It's unfortunate that I referred to the pressure associated with the heating boiling food inside the pot (wich is extremely small, but still enought to lift the lid (Is it or I'm wrong?) and pressure cookers in the same post, wich have a HUGE pressure. This realization is important for me!
PD: Are we sure that my idea of releasing vapour periodically doesn't save more than just open? To me is not so cutting obvious, it needs a proof (sorry if it's basic thermodinamics, I'm ignorant on that).
PD2: This got all really good answers! I hope you don't get put off that Im not accepting right away, but I can tell you the discussion was very good!.