Of Neolithic pastes.
I don't know why the idea of making pasta by turning off the heat before the end of cooking is so popular in Italy. And I don't know why physicists are also involved, who should know how things are: the vast majority of the energy is not spent to keep the pasta at 90/100 degrees, but to bring it from 20 degrees to 100 degrees. So the savings from this move are minimal.
And indeed, I am very surprised to see physicists waving to say that yes, you can turn off the pasta long before it is cooked, so much the thermal inertia is quite high. Ok. But the last ten minutes of cooking aren't the expensive ones.
In general, a Kilocalorie heats a liter of water by one degree. So if we bring a liter of water from 20 degrees to 100, we have spent 80 KCal. Keeping it at 100 degrees means compensating for the heat losses, and since the temperature does not drop in ten minutes, putting out the fire in those ten minutes saved very little.
You are discussing about nothing: if you were interested in energy saving, you would instead ask yourself how to optimize the phase in which you take cold water and make it boiling water.
First of all: how effective is a gas stove?
Spoiler: it's shit.
It is a cooking system that dates back to the Bronze Age, and consists in putting the hot combustion gases in contact with the bottom of the pot for a few moments (the gas then goes away), and also to make it rub on the wall if and 'quite concave (like the Chinese Wok).
The transfer is due to the fleeting contact of the gas (which escapes at the top by convention) with the walls of the pot, a contact that lasts very little and transfers little heat. The rest is dispersed in the air.
Since the pot is rounded, then, the ratio between volume and surface is optimized downwards, that is, there is little surface for a lot of volume. So it's one of the worst possible forms.
Consequently, therefore, the heat:
- serves INSIDE the pot
- you make the fire OUT of the pot
- the heat struggles to enter due to the rounded shape
I would say that it is a horrendous design, not for nothing it dates back to the bronze age, and it can only waste energy in abundance.
A SLIGHTLY better design is the magnetic induction one. A magnetic field uses the hysteresis of steel to heat it. The advantage here is that we don't have a gas that briefly rubs on the wall to go away: it is the bottom of the pan that heats up, which is a nice advantage.
However, we are not there yet. The heat comes from the bottom, the pot has problems because it has a bad shape that maximizes the volume, and then there are the losses in the magnetic coupling, the phase shift for an inductive load, etc. Also, the pot is still made of steel, which causes it to emit a lot of heat.
The general problem with classic cookware is that the heat is generated OUTSIDE the saucepan and has a hard time getting into it. When it's already in, the damage is done and the waste has happened.
Could it be that 2000 years of technology have never solved the problem of an efficient pot? Of course they solved it.
This is a reiskocher, or Rice Cooker, which also exist in Italy. They can also be used to make pasta, and have a huge advantage:
the heat arises INSIDE the pot, and if anything, it struggles to GET OUT, because the pot is insulated.
In fact, if you want to spend something more, you can buy some that are ceramic insulated. And that island. And how if it isolates.
The fact that it is worthwhile can be seen by making a comparison: the last product I put in has a power of 200Wh. The induction cooker, which you use for large pasta pans, has at least a thousand.
Apparently, the gas stove is on much higher figures:
Now, you understand that as much as you assholes can turn off the stove BEFORE the pasta cooks, those first 15 minutes you did at 3Kwh, with RIDICULAR heat transfer efficiency, an object that spends 200Wh because it is well insulated, you can't see it. neither. With your gas cooker you start wasting immediately, while a reis cooker only wastes heat when you open the lid.
Point.
The truth is that these are facade operations, which reveal the Italian mentality that, in my opinion, has done the most damage: don't touch the existing one, there must be a trick to make it modern and effective.
No, there is not'. If we want energy efficiency, stoves must disappear from homes, replaced by electric pans with strong insulation. In this way, the heat is generated inside the pot and remains there. The end of an era? The end of an era.
But in Italy no era must ever end.
The way of cooking by heating a dish by contact dates back to the Bronze Age. It has horrendous thermal efficiency, and as much as it has been optimized by moving from embers to the stove, the stove itself has had its day.
If you really want to save, use modern technologies. Spend those 30 euros for a kettle of rice, which is programmable enough to make pasta with it, and forget the TV cagnara.
Ah, yes: using these kettles to make pasta, it takes even less time to boil the water.