Microwave

[Christopher Haatuft]

We're having this discussion at work on why its bad to microwave. I havent gooten a good answer yet, so I ask you. I checked McGee, but he couldnt help me...So far the reasons I got are these;

1. "The microwaves stay in the foodstuff after you take it out of the oven."

2. "The microwaves kills all vitamins"

Well, this sounds more plausible, but I cant see why they would kill vitamins more than heat radiation.

In high cuisine, when is it ok to microwave? Would Ramsey, Keller or Adria ever be cought dead using one?

[melkor]

I use my microwave to defrost stocks, melt butter, and dry fresh herbs. That's pretty much the whole list. Microwaved food has a foul texture and it never cooks evenly.

[JayBassin]

Microwaves do not linger in the food. Microwaves do not "kill" vitamins.

Microwave radiation is a more penetrating form of energy than thermal radiation (radiant heat), which is why it cooks faster. Microwaves excite certain types of molecules more than others, which is why food products can heat (or cook) unevenly. The distribution of microwaves in a mW oven is not perfectly even due to the size of the oven and the mechanics, which also contribute to the unevenness of mW cooking. Therefore, I think that professional kitchens avoid final cooking with mW because (1) it doesn't produce even and reproducible results; (2) it can result in textural changes (try nuking a dinner roll) that are different than you get in a radiant-heat oven; and (3) there is a cultural bias against it because it was created for the home kitchen (same reason you don't see many crock-pots in professional kitchens).

IMHO.

[fifi]

The waves staying in the food makes me despair of the science literacy of this nation. Same goes for the vitamins.

Here is what I do in a nuker . . . reheat coffee, defrost stock, soften butter, popcorn, ummm . . . That is about it. I have this particular aversion to anything with meat in it going in there. It seems to come out tasting and feeling funny to me. I wrap leftover meat in foil packets and throw it in the DeLonghi convection toaster oven. So . . . why do I have one? 'Cause it came in the apartment?

My sister thinks I am nuts and says that I have a deep seated complex about microwave ovens because hers is bigger than mine. But I did get this Microwave Fudge recipe from her that only works in one of the darn things. It is very good fudge, too.

[Toliver]

The negative I've heard about microwaves is that you're not supposed to wrap/cover foods with certain plastic wraps due to the chemicals in the plastic wrap leeching onto the food during the heating process. Also, some older plastic food storage containers shouldn't be used in the microwave for the same reason.

Also, don't microwave any sort of bread in the microwave.

No scientific reason.

Microwaved bread/buns just suck.

[Jinmyo]

Makes pretty poor toast.

[francois]

I used to have a microwave to got rid of it. It would never get use so it just took valueable counter space.

I simply do not enjoy cooking in a microwave. The interaction with the food is not the same. Cooking is the only art form that I know of where you use all of your 5 senses. In a microwave, the food being cooked is in a 'box'. You can't sense it in the same way. It is just no fun!

[Gifted Gourmet]

Because I am hardly a Luddite, I do use my microwave for some foods. I occasionally reheat some leftovers in it, bake sweet and white potatoes, defrost some frozen items (gingerly), make popcorn in it, rewarm a cup of coffee or tea (but very briefly), and, I forgot, melt chocolate.

I hate to have crisp foods degenerate into soggy masses ... generally, it is a kitchen appliance that I could have survived quite well without.

[jsolomon]

Microwave radiation is a more penetrating form of energy than thermal radiation (radiant heat)

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Actually, that's not true. Because microwaves oscillate at a frequency specific to being absorbed by things like water molecules, they penetrate less far than thermal radiation. There is actually some very elegant theoretical dealings with how far various energies of electromagnetic radiation penetrate matter based on their wavelength. Since microwaves are longer wavelength than radiant heat (infrared), they penetrate less far.

This is doubly so because they are at fundamental frequencies which interact with the molecules based on quantized energy levels (booyah quantum mechanics).

So what are microwaves good for? Popping microwave popcorn, making Kraft Eezy Mac, heating Cheez-Whiz (why would anyone purchase something with "whiz" in the name is beyond me), melting generally anything that is fully liquid once heated (you can't melt a boiled egg no matter how you try), blowing up eggs...

[Christopher Haatuft]

Ok, thanks. But as far as I read, theres no danger attached to it. The only affect is the textural difference?

[Dian]

How does a microwave convection oven work? Do you think I could bake a small cake in one? I mean, it seems to work fine (not great) with a small roast so why not a cake?

[Daniel Rogov]

Fanatic no but adamant yes. Over years of experimentation I have found that many foods lose at least some of their flavor when exposed to this method of cooking and that many foods when cooked or re-heated in the microwave tend to become soggy. If not out-and-out soggy, at least harming the texture of most of the dishes with which I have experimented.

My own experience with microwave ovens is that they are most appropriate for preparing artichokes and the warming of baby bottles. I'll go along as well with a suggestion from one of my own readers that they have their place on small yachts where slapping waves do not make for comfortable cooking and where cooking space is at a minimum.

I am, however, willing to concede to being somewhat of a traditionist and that may account for part of my attitude. I do, for example, own a food processer. Despite that, it is most often to the mortar and pestle that I turn. And yes, I have tasted sauces and pates made with both methods (food processor and mortar and pestle) and in a significant number of tests can recognize the difference between them.

Like Melissa, I am not (at least I hope I am not) a Luddite and am all for progress, invention and innovation, even when those turn part of our world topsy-turvy. I do, however, insist that some traditions remain traditions because they are indeed better.

[JayBassin]

How does a microwave convection oven work? Do you think I could bake a small cake in one? I mean, it seems to work fine (not great) with a small roast so why not a cake?

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Wikipedia has a good summary of how they work. Essentially, the microwave energy excites molecules like water that have polar asymmetry---one end of the molecule is positive and the other end is negative. The molecules try to line up with the microwaves, but because the waves switch polarity rapidly (roughly 2 billion times per second), the food molecules vibrate rapidly and thus heat up. Liquid water is extremely polar; fats, oils, and sugars are less so. The polar molecules like water heat up quickly, and other molecules heat up by conduction (a slower process), which contributes to uneven heating.

I think in general starches are not too good in a microwave. Baking a potato "works" in a microwave because starch takes a long time to heat under microwave radiation, which means the relatively smaller amount of water in the potato heats up and cooks the starch by conduction.

Boiling sstraight water in a microwave can be dangerous because you can "superheat" the water---raise the temp above 212F without boiling, but as soon as the water is agitated (or if you stick a spoon in), the water will burst into steam and boil.

[JayBassin]

Microwave radiation is a more penetrating form of energy than thermal radiation (radiant heat)

←

Actually, that's not true. Because microwaves oscillate at a frequency specific to being absorbed by things like water molecules, they penetrate less far than thermal radiation. There is actually some very elegant theoretical dealings with how far various energies of electromagnetic radiation penetrate matter based on their wavelength. Since microwaves are longer wavelength than radiant heat (infrared), they penetrate less far.

This is doubly so because they are at fundamental frequencies which interact with the molecules based on quantized energy levels (booyah quantum mechanics).

So what are microwaves good for? Popping microwave popcorn, making Kraft Eezy Mac, heating Cheez-Whiz (why would anyone purchase something with "whiz" in the name is beyond me), melting generally anything that is fully liquid once heated (you can't melt a boiled egg no matter how you try), blowing up eggs...

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Microwaves do not cook by inducing excited molecules to a molecularly specific frequency. While spectrometers work by distinguishing excited molecules by their induced emission of a characteristic energy, microwaves cook food by causing polar molecules like water to vibrate rapidly (commercial microwaves operate at a frequency of about 3250 mHz, or 3,250 million cycles per second). See Wikipedia's article on microwave cooking for a good overview of how it works and the history of microwaving.

Harold McGee has a good summary of microwave cookery on page 786 of his new book. He says "Microwaves can penetrate foods to a depth of about an inch/2.5 cm, while infrared energy is almost entirely absorbed at the surface. Because heat radiation can travel to the center of foods onlyby the slow process of conduction, it's easily beaten by microwaves, with their substantially deeper reach."

[mrbigjas]

reheating soups. since everything in a soup is all wet already, the soggifying effect of microwaving doesn't make much difference.

and beans. make a big pot of beans of most any type--mexican style, baked, bean soup, you name it--freeze them, and then a couple weeks later take them out. there's no better way of reheating them than a microwave, and it doesn't affect the texture noticeably.

same with greens. if you're gonna take the time to cook and clean a bunch of collards, why not freeze the leftovers? they microwave well.

as far as the general uses that everyone seems to go by:

melting butter in a microwave always causes explosions for me. i've never figured out why, but it's always a delicate balancing act between getting it melted and having butter all over.

microwave popcorn sucks compared to popcorn in a pan. it really does.

jacques pepin had a good tip for baked potatoes on his fast food my way show, where he said to turn your oven on, scrub your potatoes and put them in the microwave, and they'll be nearly done at the same time your oven is heated--then you can transfer them to the oven to crisp the skin for a couple of minutes. i liked that idea.

that said, i want a smaller microwave. i'm not sure mine is worth the counter space it takes up--it's huge.

[ChryZ]

I'm using the microwave oven rarely, but I've made an interesting discovery. It's actually possible to crisp up food, that lost it's crispness. It only works with food that is dry and that humidified a little. I was able to dehumidify nori seaweed to it's former crispness. Nachos crisp up nicely too ...

[jsolomon]

Microwaves do not cook by inducing excited molecules to a molecularly specific frequency. While spectrometers work by distinguishing excited molecules by their induced emission of a characteristic energy, microwaves cook food by causing polar molecules like water to vibrate rapidly (commercial microwaves operate at a frequency of about 3250 mHz, or 3,250 million cycles per second). See Wikipedia's article on microwave cooking for a good overview of how it works and the history of microwaving.

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Uhh, JayBassin, you've got some fundamental errors in your understanding due to the fundamental errors in the Wikipedia article. 2450 MHz is not the fundamental frequency of water vibration. Water vibrates in the infrared range. Microwaves operate in the rotational energy range. Also, they operate at fundamental frequencies of light, not matter. So, we're talking about nu = E/h where frequencies absorbed depend on the energy of the transition.

Read the blue text.

[Malawry]

I use it to melt butter, boil water (I don't own a kettle), warm up coffee and soups. Some braised dishes I'll warm up in the mic. My big secret shame: I put leftover cold steak in the mic sometimes, but only long enough to take the chill off...I like it at room temp but not cold from the fridge. We're talking only 30-45 seconds here, any longer and it gets truly nasty. I also zap wet ingredients (milks especially) for baking to bring them to room temp.

[jsolomon]

When I make hot chocolate (from scratch, naturally) I heat the milk in the microwave while I'm boiling the sugar, water, salt, and cocoa so I don't have to stir so long at the stove.

Then, I dump in 2 jiggers of hazelnut liquor and get soused.

[BarbaraY]

melting butter in a microwave always causes explosions for me. i've never figured out why, but it's always a delicate balancing act between getting it melted and having butter all over.

I have been melting butter in it for years and it works fine for me. Perhaps your setting it too high.

I agree that microwave popcorn sucks but I do it anyway if I want a late snack and don't want to have another pan to wash.

I find that chicken thawed in the microwave is tough.

Reheating leftover is a good use for some dishes like soups. Mine has a reheat feature with a heat sensor that is OK but not for anything that should be crisp. Pizza gets reheated in the convection setting.

[bobmac]

In my previous life, we used to somehow reheat fried clams in the micro and they would come out as if they had just emerged from the fryer. I know this makes no sense, but somehow it worked. I think it had to do with the setting, but I refuse to ask my ex-wife.

[Toliver]

Regarding my earlier post and the plastic/chemical issue, here's another current discusion on part of the problem:

"Bisphenol-A, Another Controversial Chemical..."

I have done a lot of research into the safety of lexan on both sides of the fence and have come to the conclusion that if you do not expose this plastic to extreme conditions and harsh chemicals, it is safe to use, but many people use harsh detergents (bleach) and expose them to extreme conditions (such as microwave ovens and extreme heat).

The bolding of text was mine, for emphasis.

[fifi]

Regarding my earlier post and the plastic/chemical issue, here's another current discusion on part of the problem:

"Bisphenol-A, Another Controversial Chemical..."

I have done a lot of research into the safety of lexan on both sides of the fence and have come to the conclusion that if you do not expose this plastic to extreme conditions and harsh chemicals, it is safe to use, but many people use harsh detergents (bleach) and expose them to extreme conditions (such as microwave ovens and extreme heat).

The bolding of text was mine, for emphasis.

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This bug bear comes up ever so often. In reality, you are unlikely to encounter polycarbonate (e.g. Lexan, BPA issue) in containers that you would use in a microwave. It does show up in the large storage containers that you see in restaurant supply places. The other "potential" problem would be vinyl plastics (PVC) with plasticizers. I haven't seen any of that in food containers in a long time, if ever.

Neither of these plastics are used in plastic wraps. They are made primarily from polyolefins, like polypropylene, polyethylene and their "mixtures" which are inert plastics with no additives or any of the components from manufacture that are there to leach out. These plastics are also used in deli containers and freezer containers. The recycle codes could be PP, PE, HDPE.

One exception in the wraps is the original Saran Wrap which is polyvinylidene chloride. It, too is inert with no additives. Its claim to fame is that it is much more impermeable than the others. For a vivid demonstration of this, cover guacamole on the surface with Saran and the plain stuff. The Saran will keep it from blackening for a loooong time. It will also withstand higher temperatures. If there is a code anywhere it would be PVDC.

The other plastic common for food is polyethylene terphthalate. This is the stuff used in water and soft drink bottles. It is also now used in some of the frozen food containers that you can put in the oven. It is also an inert plastic with no leftovers from manufacture and has been studied to death. The code is PET.

Rest assured that any plastic used for food packaging is studied to death. I don't hesitate to use anything that is marketed by a reputable firm for food packaging and/or microwaving.

[chow guy]

[Read the blue text.

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Great link. Thanks

[mtigges]

I haven't had a microwave in years. Over ten probably. I don't miss it ONE bit. Useless piece of junk in my opinion. If all you're using it for is melting solids, what a waste. One centimeter of water in a small pot, and a small stainless mixing bowl ... double boiler, does the job way more efficiently (I'm guessing on that actually), it's certainly more enjoyable. Reheated foods from the microwave generally are unpalatable, except soups. Warmed up coffee no matter how you warm it is gross.

Popcorn? Well, I'm not a big fan of imitation butter, but you could do it AB's way. But I prefer making popcorn on the stove top.

Throw the silly things out and put some flowers there if you don't need the counter space. Sorry for my rant, but microwaves are really only good for one kind of kitchen, communal lunch kitchens at work.

Carry on,

Mark.