2

votes

Microwaving - is twice the time at half power better than full power?

Answered on August 19, 2014
Created May 16, 2011 at 3:11 PM

If you do use a microwave (setting aside for the moment the issue of "whether" you should microwave at all, which is addressed in part here), are there practical benefits to microwaving at lower power settings? Or is full power at a short time better than half power at twice the time?

D30ff86ad2c1f3b43b99aed213bcf461

on May 17, 2011
at 11:03 PM

Sweeeeet; thanks! Makes me wish that I had a gas stove to try.

510bdda8988ed0d4b0ec0b738b4edb73

(20888)

on May 17, 2011
at 06:13 PM

Ok, I'm going to nerd it up (30 sec of googling found me this http://www.physics.usyd.edu.au/teach_res/projects/proj6/attenuation.pdf) which shows that the 1/e for microwave intensity is about what you say 10-30mm in pure water. But the density of absorbers in food is much smaller than pure water, so I'd say that the 1/e of intensity is probably 10 times as much. Plus in microwaves you create standing waves which changes the propagation patterns some. Either way. I am surprised that there is so much attenuation!

5de2fffda92c0bf2be7ede10cad55546

(1781)

on May 17, 2011
at 01:13 PM

Microwaves only penetrate the food for about 35 to 50mm, any cooking after that is by normal convection, like in a regular oven.

07ca188c8dac3a17f629dd87198d2098

(7970)

on May 16, 2011
at 07:57 PM

I learned it from my dad who makes hollandaise more the old fashioned way, using a double boiler. I don't bother with that; I make mine in a metal bowl over an open flame (whisking the whole time). I used to have to watch out to make sure the eggs/lemon didn't get too hot and THEN pour in the melted butter, but if you add unmelted better slices before heating, the slowly melting butter helps keep the eggs/lemon from getting too hot too quickly. Open flame technique detailed here: http://is.gd/yVunQX

510bdda8988ed0d4b0ec0b738b4edb73

(20888)

on May 16, 2011
at 07:00 PM

Depends on the container. Glass will stay cold, some plastics with OH groups should warm up. I've done it :)

03fa485bfd54734522755f47a5e6597e

(3944)

on May 16, 2011
at 06:55 PM

I almost wish I still had a microwave, so I could put an empty container in it and see if it gets hot without food to radiate heat at it.

D30ff86ad2c1f3b43b99aed213bcf461

on May 16, 2011
at 06:43 PM

Hear, hear! Hollandaise details, please!

510bdda8988ed0d4b0ec0b738b4edb73

(20888)

on May 16, 2011
at 05:49 PM

Well, that's because it's in a container that's keeping the outside from radiating the heat away. Plus if it's frozen inside it will take longer to heat up the middle. And finally, if it has lots of water (say soup), then the outside water will absorb most of the microwaves and there will be less energy getting to the inside.

Medium avatar

(5136)

on May 16, 2011
at 05:02 PM

new hollandaise sauce making method?? you can't just taunt us like that then leave us hanging...

03fa485bfd54734522755f47a5e6597e

(3944)

on May 16, 2011
at 04:07 PM

I know your description is how it's *supposed* to work, but has anyone ever had a microwave that actually heated things evenly? Every one I've owned heated the outside much faster than the inside -- usually making the container blistering hot while the center of the food was still cold.

07ca188c8dac3a17f629dd87198d2098

(7970)

on May 16, 2011
at 03:55 PM

Yes, *most* of my use of the microwave is just for heating butter and coconut oil - though I do it less for butter these days due to the 'new' way I make hollandaise sauce now ;)

D30ff86ad2c1f3b43b99aed213bcf461

on May 16, 2011
at 03:40 PM

Yea, I'm not a fan of the "microwaved texture" either, though I still do it sometimes, especially with leftovers. At this point my other most common microwave applications are heating water and melting butter or coconut oil.

Frontpage book

Get FREE instant access to our Paleo For Beginners Guide & 15 FREE Recipes!

5 Answers

5
9aa2a816c61170cc0183a68be0386ba5

on May 16, 2011
at 04:04 PM

The only reason to cook lower power for a longer time is to maintain texture in your food. It's extremely easy to overcook things in an instant or dry up the moisture to the point that you're eating shoe leather. Eggs are a pretty good example of this. Really easy to overdo it in a microwave.

Microwaves act on the water in the food, they do not "irradiate" your food. There is no danger, unless you're using a microwave in which the shielding has been breached - in which case it would not function properly for very long anyway.

3
B124653b19ee9dd438710a38954ed4a3

(1634)

on May 16, 2011
at 04:10 PM

NO it's not directly better to use lower power settings.

Why: Most microwaves do not change power/intensity.
To reduce power they take breaks. It's that sound change you hear at lower powers, such as when defrosting.

What's important is the time of exposure. Sadly I can't find the study that I read regarding this. Will update if I find it.

But there are uses for lower powers, such as defrosting, and cooking certain items like eggs that respond/taste better when they get short breaks from the heat/radiation.

3
07ca188c8dac3a17f629dd87198d2098

(7970)

on May 16, 2011
at 03:37 PM

I would the the answer is "maybe" - it depends on what it is about microwaving you think is the most harmful.

With a lower power setting, the power is the same but it's not applied constantly - your microwave cycles between full power and off. So if you're primarily worried about superheating your foods, this will be better. If you're worried about the "radiation", then it's probably that's it's every bit as bad.

That said, I'll still use a microwave when I have to, but I greatly prefer not to. Somewhat for fears of negatively impact the healthfulness of the foods, but primarily due to concern about how negatively it affects the foods taste and texture.

Because I generally can't stand how food tastes/feels when it comes out of the microwave.

D30ff86ad2c1f3b43b99aed213bcf461

on May 16, 2011
at 06:43 PM

Hear, hear! Hollandaise details, please!

07ca188c8dac3a17f629dd87198d2098

(7970)

on May 16, 2011
at 03:55 PM

Yes, *most* of my use of the microwave is just for heating butter and coconut oil - though I do it less for butter these days due to the 'new' way I make hollandaise sauce now ;)

07ca188c8dac3a17f629dd87198d2098

(7970)

on May 16, 2011
at 07:57 PM

I learned it from my dad who makes hollandaise more the old fashioned way, using a double boiler. I don't bother with that; I make mine in a metal bowl over an open flame (whisking the whole time). I used to have to watch out to make sure the eggs/lemon didn't get too hot and THEN pour in the melted butter, but if you add unmelted better slices before heating, the slowly melting butter helps keep the eggs/lemon from getting too hot too quickly. Open flame technique detailed here: http://is.gd/yVunQX

D30ff86ad2c1f3b43b99aed213bcf461

on May 17, 2011
at 11:03 PM

Sweeeeet; thanks! Makes me wish that I had a gas stove to try.

Medium avatar

(5136)

on May 16, 2011
at 05:02 PM

new hollandaise sauce making method?? you can't just taunt us like that then leave us hanging...

D30ff86ad2c1f3b43b99aed213bcf461

on May 16, 2011
at 03:40 PM

Yea, I'm not a fan of the "microwaved texture" either, though I still do it sometimes, especially with leftovers. At this point my other most common microwave applications are heating water and melting butter or coconut oil.

2
6a4fd73b4ae4761eefec8e0d38e6f224

(1008)

on May 16, 2011
at 03:54 PM

I like to poach eggs in the microwave, and lower/slower works better. For mine, about a minute at 80% does the trick; at the office, 1:20 or so at 70%. At higher power and shorter time they turn rubbery on the outside and stay raw in the middle.

2
510bdda8988ed0d4b0ec0b738b4edb73

(20888)

on May 16, 2011
at 03:44 PM

Lets look at how the different ways to cook food work:

A standard oven/fire/external heat source works by heating up the outside of the food and starts cooking that part. The heat then slowly gets conducted to the inside and cooks that part. You can think of it as cooking from the outside-in. This is why you don't double the temperature and cook for half the time. You burn the outside and don't leave enough time for the heat to reach the inside.

A microwave works by aiming microwaves (convenient name, huh?) which are about 1 foot long at the food. These waves are at the correct frequency to shake water molecule (really -OH libration, so fats and sugars also interact with the microwaves) and heat it up. The microwave goes through all of the food at once and shakes all of the water molecules at once, so the food heats up evenly. Now, the inside heats as fast as the outside, but the outside actually can conduct its heat to the surrounding air and it cools down. So you actually heat the inside faster than the outside. You can think of it as cooking from the inside-out.

I would think that as long as you cook the food long enough to get to the proper cooking temperature, that a long-low power is probably "more gentle" on your food than a short high-power. But remember, your microwave doesn't adjust the power of the waves, they are what they are (for mine is 1500W), it just adjusts the duty cycle (how long the waves are on). So for something big, say a hunk of chicken, it's probably better to go slow because you're giving time for the heat on the inside to equalize with the outside. For something thin, like bacon, it probably won't make any difference other than you having to wait longer for your bacon.

03fa485bfd54734522755f47a5e6597e

(3944)

on May 16, 2011
at 04:07 PM

I know your description is how it's *supposed* to work, but has anyone ever had a microwave that actually heated things evenly? Every one I've owned heated the outside much faster than the inside -- usually making the container blistering hot while the center of the food was still cold.

5de2fffda92c0bf2be7ede10cad55546

(1781)

on May 17, 2011
at 01:13 PM

Microwaves only penetrate the food for about 35 to 50mm, any cooking after that is by normal convection, like in a regular oven.

03fa485bfd54734522755f47a5e6597e

(3944)

on May 16, 2011
at 06:55 PM

I almost wish I still had a microwave, so I could put an empty container in it and see if it gets hot without food to radiate heat at it.

510bdda8988ed0d4b0ec0b738b4edb73

(20888)

on May 16, 2011
at 05:49 PM

Well, that's because it's in a container that's keeping the outside from radiating the heat away. Plus if it's frozen inside it will take longer to heat up the middle. And finally, if it has lots of water (say soup), then the outside water will absorb most of the microwaves and there will be less energy getting to the inside.

510bdda8988ed0d4b0ec0b738b4edb73

(20888)

on May 16, 2011
at 07:00 PM

Depends on the container. Glass will stay cold, some plastics with OH groups should warm up. I've done it :)

510bdda8988ed0d4b0ec0b738b4edb73

(20888)

on May 17, 2011
at 06:13 PM

Ok, I'm going to nerd it up (30 sec of googling found me this http://www.physics.usyd.edu.au/teach_res/projects/proj6/attenuation.pdf) which shows that the 1/e for microwave intensity is about what you say 10-30mm in pure water. But the density of absorbers in food is much smaller than pure water, so I'd say that the 1/e of intensity is probably 10 times as much. Plus in microwaves you create standing waves which changes the propagation patterns some. Either way. I am surprised that there is so much attenuation!

Answer Question


Get FREE instant access to our
Paleo For Beginners Guide & 15 FREE Recipes!