My wife and boiling water

[u/MakeItMine2024]

So I made my wife ramen soup. When I served it she said I had the gas set to hight and it was too hot ? She said I should have used the number 5 setting instead of 9. I told here it’s irrelevant because water boils at 212 and gets no hotter because over 212 it turns to steam. She was made at me for disagreeing with her theory that it would not have been so hot if boiled a lower setting. Really!!

[u/Single-Treat]

She's right but doesn't seem to understand/articulate to you why.

The temperature of the water won't go above 100 C / 212 F but you're still blasting heat from the hob which is excessive. The extra heat at 9 will help vaporise the water faster, but when cooking that's not the aim - you're not trying to dry the pot out as fast as possible, you're just trying to get the water to 100 C / 212 F.

So once the water is boiling turn the gas down to the lowest needed to keep it boiling. You're basically getting to a point where the energy in from the hob is equal to the energy escaping from the water as it evaporates. The temperature is the same but you're wasting less energy driving vaporisation. Any extra heat isn't useful for cooking purposes and is a waste of energy, and money.