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A recipe asks for a teensy cake to be cooked on High for 70 secs in a 950 watt microwave.

What temperature would 'High' be? like in Celsius or Farenhite

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  • Ah ok! I guess what i was trying to do was to try the recipe in a conventional oven with temperature settings... Maybe the right question to ask would be- What temperature would food likely be after microwaving it for 70 sec on high? – RSF Jan 15 '15 at 8:46
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    "High" refers to power, not temperature. For example, if you are heating up a dish, but you don't want all the moisture to evaporate and make the dish dry up, you would turn your power down to 60 or 70 percent (or maybe "medium"). – fuzzy_onesie Jan 21 '16 at 15:14
  • In some cases, you can assume temperature from microwave instructions. For example, if it's a Heat-Treated, Not-Fully-Cooked, Not-Shelf-Stable food product with Safe Handling Instructions as well as Cooking Instructions, the cooking instructions will require annual revalidation that the minimum internal temperature required is reached with the stated cooking time and wattage (if a range is stated, the floor value still needs to pass trial). Since over-cooking often deteriorates quality, most QA teams would try to minimize the tolerance margin while still reaching lethality (e.g., 165°F). – Arctiic Aug 4 '19 at 14:03
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It is impossible to convert Microwaves into Celsius or Fahrenheit.

Temperature(Celsius):

Temperature is a measure of the average translational kinetic energy of the molecules of a system. Heat is commonly expressed in either of two units: the calorie, an older metric unit, and the British thermal unit (Btu), an English unit commonly used in the United States.

Energy(Watt):

Power is the rate at which energy is generated or consumed and hence is measured in units (e.g. watts) that represent 'energy per unit time'. For example, when a light bulb with a power rating of 100W is turned on for one hour, the energy used is 100 watt hours (W.

Microwaves are essentially radiation bombarding your food and causing the water molecules inside to get excited/vibrate, this in turn causes heat (Think rubbing your hands together).

If you are told to put something in a Microwave oven for 70 seconds, it is just a tried and tested method of getting the food to the correct internal temperature. You can't compare it to a standard oven.

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    We don't live in an ideal world. In empty oven, that 950 watts goes into heating the glass turntable, oven walls, magnetron, and other components in the microwave. You can do all kinds of unwise things in a microwave without a wet thing in it to absorb the energy. Like, make lava. – Phil Frost Jan 14 '15 at 14:39
  • Have edited my answer as there seems to be conflicting 'facts' regarding how much energy is used in an empty microwave ovens. Some people say none, some people say it builds and builds till... bang. – Doug Jan 14 '15 at 14:49
  • It's an easy question to answer: put an electrical power meter like a Kill-A-Watt on the microwave and turn it on. All that energy is going somewhere, and it's probably making something hot. If it's not making the food hot, it's probably making the microwave hot, probably until either the microwave's protection circuits cut the power (if you are lucky) or the microwave is damaged (if you are not so lucky). – Phil Frost Jan 14 '15 at 14:53
  • of course, 70 seconds on a 950 W microwave (~18.5 Whr) will be different than for an 800 or 1200 W microwave. (~15.5 and ~23.3 Whr) So time estimates are only guidelines, not firm times. – Joe Jan 14 '15 at 15:00
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    @coburne: Various materials absorb microwaves to differing degrees. If one puts three objects in the microwave and one absorbs 10x as much as the second and 100x as much as the third, then a nominally-950W microwave might put 800W into the first, 80 into the second, 8 into the third; if the first were removed, the second might get 750W and the third 75W. The microwave might draw less electricity in the latter case. – supercat Jan 14 '15 at 16:52
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This chart displays Watts with the corresponding temperature. This is not a conversion table but the temperature measured by heating 300ml water in a Samsung Microwave on different Watts / timings. I hope this helps

        1 minute | 2 minutes | 3 minutes

100W : 35C/95F | 37C/98.6F | 40.8C /105.4F

180W : 37.4C/99.3F | 44C/111.2F | 47C/116.4F

300W : 43C/109.4F | 49.5C/121.1F | 59.7C/139.4F

450W : 48.5C/119.3F | 62.2C/143.9F | 74.8C/166.6F

600W : 54.4C/129.9F | 76.7C/170F | 90.3C/194.5F

800W : 60.2C/140.3F | 87.8C/190F | 100.6C/213F

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    While I trust you recorded these temperatures correctly, I don't see what use you suggest others can make of it. Foods other than water, or foods heated in a different bowl from yours (both material and shape matter!) will end up a very different temperature. – rumtscho May 11 '15 at 8:56
  • rumtscho is correct on how different containers in both shape and material make a big difference in how hot food or liquid will get in a microwave. 100 ml of a liquid is heated in a narrow cup will take longer to reach the same temperature compared to 100 ml liquid in a shallow wide bowl. A lot depends on surface area exposed to microwaves. Fats as heat to a higher temperature than water. – Jude Jun 26 '17 at 23:05
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I assume you mean what temperature would your food be after microwaving it? It depends on the food.

A microwave isn't getting hot like an oven does. It shoots microwaves at your food which causes the food to heat up a certain amount. The amount it heats up depends a lot on its water content, mass, etc.

A microwave is going to transmit a fixed amount of energy to your food in a given time frame. This energy will be converted to heat. However since its a fixed amount of energy it depends on what is receiving the energy that determines how much its heated up. A 100 pound steak will rise in temperature much less than the 1 pound steak because there is more of the 100 pound steak to heat up.

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I've been using the following basic guidelines, but I do feel the need to gather more accurate information so will be following up with scientific method.

100% - - - - -Hi - - - - -425-500F

70% - - - - MdHi- - - - -350F

50% - - - - -Md - - - - -300F

30% - - - - -Lo - - - - -225F

10% - - - - -Wm - - - - -150F

Converting from oven to microwave oven needs time adjustment by 75%. In other words, instead of cooking for 1 hour you nuke it for ~15min.

I've had good luck with this. My microwave was manufactured to be 1050 Watts, but I'm not sure that is helping me so I'll need to be checking it's actual output with 1 liter of water nuked on high 2:03 and then measuring the temperature between 70F and after result. Then multiplying that by 35 should get acceptably near the wattage. At least, as we used to say in the military, "close enough for government work".

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A recipe that says "70 seconds on high in a 950 Watt microwave" wants exactly that: put it in a 950W microwave for 70 seconds, at full power setting. The recipe author already worried about how hot or done the food is supposed to get from these settings; if you adjust the recipe (including doubling or halving), or use a weaker or stronger microwave, you have to estimate how much to adjust the cooking time.

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the temp chart listed above is a good foundation to understanding the rate at which the material, in this case water, is being heated up. over-cooking food is all too common and has a high probability of creating carcinogens. with water there is theoretically minimal chance of such mutations.

a slow ramp up thermally helps to cook evenly an reduce the chance of internal and external burns, physiologically speaking. *to answer the question of watts vs working temp, only experience can put things into perspective unless your a design engineer working at a microwave manufacturer.

cook a simple muffin or biscuit that has a relatively low mass/density at 30% power level. fyi, power levels on a microwave are typically duty-cycle base so 30% is still cooking at full power but only 30% of the time. think slow cooker, yes its a long wait but the results make it worth the time.

another thing to consider is that microwave ovens are notorious for uneven cooking, especially on high (100% duty-cycle). lower power level gives the thermal intensity zones time to propagate throughout the material being heated. one could think of it as thermal reaction time.

**a better question might be what is the energy/thermal density of various microwave oven power ratings.

food-4-thought

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