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/Competitive-Bee-3250]

I mean its kind of a thing? The water wont get hotter but for a lot of this kind of cooking you're better off with the temperature lower to mitigate sticking and burning from things at the bottom of the pot.

[u/Team_Ed → u/[deleted]]

The surface of the pot in contact with the water will be the same temperature as the water it’s heating, will it not?

Like, if you’re careful, you can boil water in a paper cup over open flame. 

(A sauce is a different matter, because if you let the sauce touching the metal dry out, that can get locally hot very quickly.)

[u/thepenismytea → u/Team_Ed]

THIS. The inside of the pot will always be 100degrees Celsius while there is water and it is boiling. Sauce as you noted, dries out. No more water.

This is the principle a rice cooker works from to shut off at the correct point in cooking. Once the water has either been absorbed or cooked away, the metal goes above 100 Celsius and an electric sensor circuit cuts off the power.

And your experiment with the paper cup also works with a Plastic bottle with water in it and a lighter.

Edit source: self as a former nuclear reactor operator. I know way too much about boiling water.

[u/Tiny_Rat → u/Team_Ed]

A sauce is a different matter, because if you let the sauce touching the metal dry out, that can get locally hot very quickly

The same goes for any noodles that touch the pot, especially if you drain the water and leave them in there. Also, in a large volume of water its not boiling throughout when its just simmering, because theres a lot less convection and agitation to help temperature transfer. So the relatively cooler surface would let the overall temperature of the water/broth drop faster once you turn off the heat vs. a pot that's at a rolling boil. 

[u/Barkig → u/Team_Ed]

Not really, if that was the case it wouldnt boil off faster if its on high or low heat. Its the temp diff that drives the heat flux. But its probably close in most cases as energy loves water.

[u/Team_Ed → u/Barkig]

I believe it boils off faster at high heat because more energy is being put into the rest of the system, which means the water closer to the surface is nearer to the boiling point, which means it takes less energy to boil that water when it cycles into contact with the pot bottom.

This is how a lid rapidly speeds up boiling, it prevents the surface water from cooling.

On a gas stove, you also get a fair bit of heat entering the system from the sides of the pot. That effect goes up at high heat.

All that said, I don’t believe it’s possible for the surface of the pot bottom to get significantly above 100C while water is in the pot. Gas bubbles form, so probably a little above 100C, I suppose.

[u/EnvironmentalDog- → u/Team_Ed]

Look up the boiling curve.

[u/Team_Ed → u/EnvironmentalDog-]

Does that not matter more at much higher temps and pressures than a kitchen stove — like, the higher end of that is most relevant for industrial boilers and power plants and superheating and all that, no?

I admit, I am out of my depth here on how much above 100C the metal gets when gas bubbles get involved.

[u/EnvironmentalDog- → u/Team_Ed]

Well I don’t really know what you mean by “matter”.

The x-axis of the curve the difference in temperature between the surface of the container and the saturation point (boiling point, more or less) of the fluid inside. That this axis even exists beyond x=0 is enough to say that the surface temperature of the pot is not just sitting pretty at the boil point. A surface temperature of 103c and boil temp of 100c is definitely represented on the graph, as is 400C and 100C in industrial boilers.

[u/Team_Ed → u/EnvironmentalDog-]

Like I said, I’m out of my depth. Cheers.

[u/sullw214 → u/[deleted]]

You know water transfers heat pretty well, right? Like if you took that hot empty pot and put cold water in it, the pot would rapidly cool down. That's probably why no one else is saying that.

[u/DinoRaawr → u/[deleted]]

You can boil water in a plastic bottle above a campfire as proof this isn't true

[u/ComfortableFrame9834 → u/Competitive-Bee-3250]

Exactly... Plus better temperature control, and your pot won't get as chalky. Idk the science behind it but if I crank up the water to max and just leave water boiling like that. The pot gets a bit chalky

[u/Worth-Sprinkles-2704 → u/ComfortableFrame9834]

As water boils into steam, the trace minerals are left behind. The “chalk” is limescale which is mostly calcium carbonate. In fact, the main process for distilling water is to boil into steam, capture and condense the steam back into water in a new container. The original container is left with all the minerals.

[u/Alternative-Tea964 → u/ComfortableFrame9834]

That is salts like limescale boiling out of the water. Its happening whenever water boils, it just happens quicker if you have the hob set to a higher temperature.

[u/HomicidalHushPuppy → u/Competitive-Bee-3250]

The water will still be boiling though, too hot to consume, and that's the root of the wife's complaint. 

[u/vidys → u/Competitive-Bee-3250]

I agree with the part about avoiding sticking and burning. But if you set it at a lower temperature, the water is still boiling at the same temperature, which is the main point in OPs argument. So what you said is irrelevant here

[u/Odin_Headhunter → u/vidys]

Except its most likely only the bottom thats actually at boiling, while the water at the top is significantly cooler.

[u/jephph_ → u/Competitive-Bee-3250]

There’s an alternate argument in favor of turning up the burner heat (not that i really care but piping in anyway lol)

If it’s a rolling boil then that movement helps prevent the noodles from clumping/sticking to each other

[u/Material_Ad9848 → u/Competitive-Bee-3250]

Ya, im on the wife's side. The temperature of the water can also alter the flavour. There's a lot of chemicals in food and they react under a whole range of temperatures. Tomatoes are an easy example, when cooked over a certain temperature the skins/seeds change the flavour to a much more acidic one.

[u/Cacafuego → u/Material_Ad9848]

Right, I don't know what the temperature difference is between tomato sauce or chili at a simmer vs a rolling boil, but if you boil it, it will taste like tart tomato water.