I'm Just Here for the Food (43 page)

What the heck happened to my Mars bar?

—Dr. Percy Spencer

If appliance makers are correct, some 96
percent of American homes contain at least one microwave oven. Most of these are employed in the warming of coffee, the popping of popcorn, and the occasional “nuking” of frozen foods. When you consider what this technology
is capable of, this seems a lot like using an aircraft carrier to pull a water-skier. Sure, it can do the job, but that’s not the point. The microwave oven can do some amazing things—the trick is to understand how it works well enough to know what to feed it.

But first, some history. It began, as these things often do, with a guy in a lab coat. The guy was Dr. Percy Spencer, and the lab coat belonged to the Raytheon Corporation. One day in 1946, Dr. Spencer was futzing about with a new kind of vacuum tube that (it was hoped) would revolutionize the radar industry. It was called a magnetron tube, and, after working on it awhile, Doc Spencer decided it was time for a snack. He reached into his lab coat pocket for a chocolate bar and found that it had turned to mush. It’s been a short leap from that melted candy bar to the distinctive hum heard at 3:00 A.M. in 7-Elevens across the country.

When I set out to understand the microwave, I hunted up an industry expert who prefers to remain anonymous.

Me: Uh, what’s a microwave?

Expert: A form of electromagnetic energy.

Me: Hmm. What’s electromagnetic energy?

Expert: Waves of electrical and magnetic energy that move together through space.

Me: I see.

Expert: Sure you do. Let me draw you a picture.

Me: Ah, yes. So how do you make one of these wavy things?

Expert: Well, you create an electromagnetic wave any time you feed an electric current through a conductor, such as a copper wire. But that kind of energy stays very close to the wire. However, if you oscillate it at a rapid rate…

Me: Oscillate?

Expert: Reverse polarity.

Me: I knew that.

Expert: When you do that, the electromagnetic field breaks free and a wave moves outward like ripples on a pond. In microwave ovens we use a device called a magnetron tube to create and direct these waves.

Me: Are they dangerous?

Expert: If you’re inside the microwave.

Me: That’s not really what I meant.

Expert: You have to remember that these are non-ionizing waves. They’re not that much higher in frequency than television and radio broadcast waves, which we’re exposed to all the time.

Me: Ionizing?

Expert: When the frequency of a given radiation reaches millions of cycles per second, that means it’s packing considerable energy—enough to pass through you and onto a photographic plate. With enough exposure, such waves can ionize or change cell structure—even your genetic structure, which explains why too much tanning can lead to skin cancer. Of course, the sun’s rays lose a lot of oomph while traveling millions of miles to the earth.

Me: What if the thing making the waves was close?

Expert: How close?

Me: Hiroshima close.

Expert: Let me put it this way, there’s a big difference between being hit in the head by a beach ball thrown by a three-year-old child and a fastball thrown by a major-league pitcher.

Me: Okay, so what do you say to the charge that microwaves don’t cook food?

Expert: That’s right. Microwaves don’t cook food, because food exposed to microwaves cooks itself.

Me (as I scratch my head): Perhaps you could elaborate.

Expert: Microwaves are a little odd because although they can pass straight through substances like glass and most plastics, they are actually absorbed by chemicals in food that have asymmetrical molecules.

Me: Like?

Expert: Like most fats, sugar, and especially water—that’s the big one. (Pausing I recall the Mickey Mouse-hat concept.) When these molecules absorb the waves, they begin to vibrate. This vibration causes friction with nearby molecules, and that friction creates heat—the heat that does the actual cooking.

Me: So you can cook anything in a microwave oven that contains enough of those compounds.

Expert: Yep.

Me: Okay, I got it. What about the old sales tagline about microwaves cooking food from the inside out?

Expert: Microwaves still have to penetrate food, but some foods are easier to penetrate than others. For instance, microwaves can’t penetrate a beef roast by more than a couple of inches.

Me: So you can’t cook a roast in a microwave oven?

Expert: Yes, you can. It’s just that the waves only penetrate so far. The core of the roast would cook by conduction—the old-fashioned way.

Me: Okay. Got it.

Expert: I’m not sure that you do, but I have to go.

Me: Okay. Bye, Dad.

Expert: Please don’t call me at work again.

Superheating

So, from this enlightening conversation we come to understand that anything containing water and/or fat and sugar can be cooked via microwave energy. That would seem to include just about every food on earth. The problem is a lot of the flavors we expect from food come to us via the Maillard reaction, which as we all know only results from contact with very dry high heat. Since the microwave oven itself doesn’t get hot, the Maillard reaction cannot be evoked. The water that’s on the surface of and inside the food can’t rise above 212° F (at sea level), and that’s just not good enough. In fact, the only way to brown something in the microwave oven is to—carefully—get metals involved. For instance, there are certain prepared foods that one puts inside a foil-lined sleeve before letting the waves do their stuff. That foil contraption is designed to get super hot and brown the burrito . . . or whatever. But designing such a device yourself can lead to fire and/or permanent damage to the inside of the oven, so don’t try it.

Fire can result from the super-heating of flammables such as popcorn bags. When appliance manufacturers test microwave ovens for fire containment they often use microwave popcorn as the fuel—and just to make sure there’s a fire, they insert a 10-penny nail in the bag. Since it’s dense and significantly longer than the microwave’s wavelength, the nail gets really, really hot. This is one reason microwave oven manufacturers usually discourage the use of metal containers or cooking utensils in microwave ovens.

There’s another reason. Even if the metal device doesn’t get hot enough to start a fire, it can become so electrically charged that if it comes close enough to the wall or floor of the oven it can arc. The resulting “lightning” can badly mar the oven.

The Great Popcorn Controversy

I wish to defend myself against charges of microwave abuse. A couple of years ago on a certain television program, I made microwave popcorn from scratch, using plain popping corn, a little olive oil, and salt in a small paper bag sealed with not one, not three, but two standard office staples.

Well, despite the fact that I had tested this in no fewer than ten different ovens, and despite the fact that the product was delicious and cheaper than dirt, I received tons of angry mail. People were just sure that their houses would explode.

No. Relax. It’s okay.

As long as you’re using a microwave oven with a turntable and you don’t place the bag where the staples can rub against one of the walls, nothing bad will happen. This is because staples have very little mass and they are shorter than the microwaves themselves, which means they’re basically microwave “invisible.” So don’t be afraid to try the recipe on the next page.

WHY IS POPCORN THE PERFECT MICROWAVE FOOD?

Popcorn pops because its kernels contain a high amount of moisture. When heated, that moisture eventually turns to steam. Unable to contain the increased volume of the vapor, the starchy kernel blows out in all directions and freezes in a puffy configuration, which itself results from the rapid drop in ambient pressure. Since it only heats the water portion of the kernel, microwaves can pop corn without burning it. If yours does burn from time to time, blame the oil, which can get hotter than water.

Beyond the Burrito

Okay, back to the point. Since the outer surface of foods can’t get hot enough to brown, there’s no real reason to doom foods that benefit from tasty crusts to the mediocrity of microwave cooking. But there are plenty of foods that don’t depend on such action.

Foods not to microwave: Eggs in the shell (the same principle as popcorn, but a lot more forceful and a lot more messy). Shellfish: ditto

Microwaves (the waves not the ovens) set certain molecules into motion, creating friction and therefore heat. Since water and sugar are two of the substances most affected, fruits would seem to be prime m-wave candidates, especially when a sauce is the desired result.

When it comes to microwave ovens, round containers always outperform rectangular vessels. And because the waves bounce around the cavity of the oven, I like taller rather than shorter vessels.

Homemade Microwave Popcorn

I’ve made this stuff six ways from Wednesday and until recently I always tossed the kernels in oil before placing them in the bag. But the more I learned about microwaves, the more I started to think this might be unnecessary. After all, the stuff that does the popping (water and plenty of starch) are on the inside of the kernels. The kernel itself doesn’t need to brown, so why bother with the added mess? I ran a quick test batch and never looked back.

Although many home poppers advocate the use of other culinary oils in place of butter, I just can’t break with this tasty tradition. However, I do like a sprinkle of cheese now and then. Oh, and if you’re interested, toss a tablespoon of dark brown sugar in the bag sometime.

Application: Microwave Cooking

Pour the popcorn into a paper bag and fold the top of the bag over twice to close (each fold should be ½ inch deep; remember, the kernels need room to pop).

Seal the bag with 2 staples only, making sure to place the staples at least 2 to 3 inches apart.

Put the bag in the microwave oven and cook on high power for 2 to 3 minutes, or until the pops are 5 seconds apart.

Remove the bag from the oven and open it carefully, avoiding the steam. Pour the popcorn into a bowl and drizzle it with the butter, then toss with salt and cheese, if desired.

Yield: 6 to 8 cups popcorn

Software:

⅓ cup popcorn 2 to 3 tablespoons melted butter
Popcorn salt to taste
1 tablespoon Parmesan cheese,
finely grated, or other “cheese
sprinkle” (optional)

Hardware:

Small paper bag (standard lunch
size is fine)
Stapler (use exactly 2 staples—no
more no less)
Microwave oven with a carousel
(important for even popping)
Large mixing bowl

Old maids--the biggest downside to microwave popping is unpopped kernels. I’ve never managed better than a 70-percent pop without burning some of the corn. That’s just life in the big microwave.

Tomato Sauce Rosie

There are times when you want to slowly simmer a sauce all afternoon on the cook top. And then there are the times when you just want to eat something. The microwave oven is here to help—so let it.

Application: Microwave Cooking

In a microwave-safe glass dish, combine the oil, garlic, shallot, onion, and chile flakes. Put the dish in the microwave oven and cook on high power for 1 minute.

Remove the dish from the oven, add the tomato sauce and the diced tomatoes, then tightly cover the dish with plastic wrap. Pierce the film twice to allow steam to escape, return the dish to the microwave oven and cook on high power, for 2 minutes. Allow the dish to rest, covered, in the oven for 2 minutes, then remove, take off the plastic wrap, and stir in the basil, parsley, sugar, and salt and pepper to taste. Serve over your favorite pasta.

Yield: Approximately 3
½
cups sauce

Software:

1 tablespoon olive oil
2 tablespoons thinly sliced garlic
2 tablespoons minced shallot
1 cup diced yellow onion
½ teaspoon chile flakes
1 (14-ounce) can unseasoned
tomato sauce
1 (14-ounce) can unseasoned diced
tomatoes
2 heaping tablespoons basil, cut
into fine chiffonade
¼ cup chopped fresh parsley
2 teaspoons sugar
Kosher salt
Freshly ground black pepper