5

Should I use low or high temperature to use a stove energy efficiently? If I use low temperatures a lot of energy will be wasted with time, but using high temperature is not energy efficient as well. So what's more economic?

  • Protip for cooking Italian pasta: if the cooking time is X minutes, you can turn off the gas at X/2 minutes. Make sure to cover with the lid to maintain the heat. – Aubrey Jun 13 '15 at 19:29
  • The question really doesn't make a lot of sense, as cooking the same materials at different temperatures will give you different results. E.g. you could slow-cook meat & vegetables for a few hours and get a tasty stew, or stir-fry them at high temperature for a few minutes. – jamesqf Jun 23 '15 at 18:37
2

This answer won't cover all cases, but when you are cooking with water it starts boiling at roughly 100 degrees and won't get any hotter (unless you boil it dry). Unless you're steaming, cooking a reduction or need the vigorous motion of water boiling hard, you may as well turn down the element at that point to save energy.

Often foods don't cook until quite a high temperature is reached, so if you only slowly bring the food up to the required temperature then more energy will be lost. Once the temperature is adequate though, any excess heat is essentially wasted (and may burn the food or make it less healthy too). It's clearly best to aim to bring the temperature up quickly, but not overheat.

There are other ways to reduce the energy used; for example using a minimal quantity of water to boil or steam requires less energy to bring up to temperature than using an excessive amount.

  • 3
    From a gastrochemical point of view, in general reactions proceed twice as fast every Kelvin/Celsius increase in temperature. Including burning... The main reason for low temperature cooking is to allow the temperature to equalize in the food during the cooking process, so you achieve an even cook. Therefore the most efficient temperature to cook is as high as possible, whilst minimizing the thermal resistance (cut the food up). – Aron Jun 9 '15 at 6:12
  • 1
    @aron if I understand your comment correctly, you're saying that food will cook twice as fast at 191C as at 190C? I have trouble believing that. – Flyto Jun 25 '15 at 10:13
  • 1
    @SimonW Crap... I meant 10K, so food cooks twice as fast at 200C as at 190C. Can't edit it now... Problems come from distribution of temperature and phase changes, which limit temperature. – Aron Jun 25 '15 at 10:22
  • @Aron hah, right. That seems more plausible! (if still surprisingly sensitive to a layperson) – Flyto Jun 25 '15 at 11:18
1

Probably not answering the question, but I cannot resist.

It is increadable that you understand that you cook by temperature rather than by applying the energy. Maintaining the temperature, no matter how high, ideally, does not consume any energy whatsoever (likewise the body, once accelerated, maintains its speed itself. Only heat up is energy consuming. Maintaining does not consume anything. You can boil for free!). That is a law of heat from Galileo. You need an accelerator just to counteract the resistance (aka energy leakage/loss). The faster you move, the more you leak per second. This is another law of heating/cooling from Newton

enter image description here

It says that the higher is temperature, the faster you loose the energy, exponentially faster. You see the contradiction between the laws because your pan is not ideal. Galileo was first to notice that if you boil with ideal lid, your pan will keep its temperature forever, for free. You can boil for free! Wait, I repeat myself.

The bottom line is that you should always use a lid and probably wrap your pan into towels. The latter can be risky. I recommend therefore reaching the water boiling temperature quickly first, turn off the heater and cover everything with with towels. This will insulate your cooking-optimal temperature pan and you won't waste any temperature/energy at all and it is safe. It is also optimal ib terms of the fact that, as the dish cools down, it is prepared and once preparation completes, your dish has optimal temperature for consumption (in contrast to those slaves of evil who are convinced that beauty and good taste = energy waste, enjoy their fresh dish scalding). The real beauty is energy saving, when things go smoothly themselves.

Such stewing is a best way to boil pasta, eggs and various crops. The latter should be soaked in advance. Soaking = boiling at room temperature. It is free (costs no money and does not increase world entropy whatsoever). Yes, you should boil the crops and beans at room temperature first. Boil them normally, as described above, after soaking. It will be a huge saver. I think that thinly filmed potatoes will go either.

Finally, boil with as few water as possible and never dispose stem-hot water into the drain. Boil something else or use it to clean fat or recuperate. Washing steam-hot water down the drain is a (entropic) crime against the God. I normally boil the crops such that after soaking, there is left some water in the pan and it is partially evaporated and further soaked into beans during stewing. So, nothing is wasted.

But your question is interesting. It re-raises my old question, why do kitchen bosses do not produce the thermically insulated pans to enable zero-energy cooking?

  • How would you heat a thermally insulated pan? (answer may be "induction hobs". Fair comment, in that case) – Flyto Jun 25 '15 at 10:16
  • @SimonW you can buy thermally insulated pans. Typically they are marketed as camping pans (for obvious reasons, it makes a big difference here). Usually they are neoprene insulation jackets that wrap the sides on the pan. – Aron Jun 25 '15 at 11:31
  • 1
    @SimonW An object in our 3D-world has 6 surfaces: one to heat at the bottom and other 5 surfaces are used to leak the heat. I propose to insulate the cooling surfaces. There is not need to isolate from the heater. Thanks for more advanced proposal. It could push the efficiency to the limit! – Val Jun 25 '15 at 17:22

Your Answer

By clicking "Post Your Answer", you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.