Never overcooking potato water: spoon on the pot

Who does not know that? For a brief moment, do not pay attention, and already the good stove is messed up. That's enough of that.

You just have to place a wooden or wooden spatula (necessarily made of untreated wood, not painted or coated) between the pot and the lid. On the one hand, the steam can escape better and on the other hand, the starchy water is prevented from looking beyond the pot. Why is that? Unfortunately, I can not answer this question. I only know (from several self-studies) that it really works!

Should anyone know what changes (chemically or physically), may he / she please write a little explanation. Try it. It really works.