– Why does putting the top on a pot of boiling pasta make it frothy and boil over?

Question

– Why does putting the top on a pot of boiling pasta make it frothy and boil over?

In: Chemistry

Answer 1

It’s partially because the inside of the pot fills with steam instead of air, and the bubbles are a lot harder to pop by evaporation when they’re exposed to steam compared to when they are exposed to air. Starchy pasta water forms bubbles fairly easily.