Wednesday, April 02, 2008

Microwave Management

The Curious Cook

On Food and Zapping

Published: April 2, 2008

THE microwave oven is a quirky appliance. Sure, it cooks and reheats many foods quickly and well, and in containers that can go right to the table or come right from the fridge. But it can also cause a mug of hot water to erupt scaldingly, char nuts and breads on the inside, and blow up eggs and butter.

To make the most of the microwave, it helps to know its quirks, and ways to work around them.

The strange powers of the microwave arise from the basic fact that it cooks indirectly, with radio energy. Conventional baking, broiling, boiling or frying transmits a particular level of heat directly to the food. But when we zap, the air in the microwave oven barely gets warm. Instead, the oven emits radio waves that penetrate the food from all directions and generate heat within the food itself — until the oven turns off.

Of the substances in food, water is especially quick to absorb microwave energy. When it does, the water molecules move faster, crash into the more sluggish proteins, carbohydrates and fats, and jolt them into motion, raising the temperature of the food as a whole.

This constant heat generation can create temperatures beyond the boiling point. That often means trouble.

Microwave an egg in a shell long enough to turn some of its moisture into steam — about a minute — and the pressure shatters it. Microwave butter long enough to melt it, then continue heating the water that settles to the bottom, and that water will boil and splatter butterfat all over the oven. Microwave a mug of water long enough, and it can superheat past the boiling point without bubbling, then bubble violently the moment you disturb it.

So keep close tabs on cooking, and turn off the oven as soon as the food is done. Medium and low oven settings are useful because they pulse the radio waves on and off and slow the heating so that it’s easier to control.

The lack of precise temperature control in a microwave means that it’s not ideal for meats, fish or egg dishes, which toughen when slightly overcooked. Even when reheating stews, it is best to remove the meat or fish, microwave the liquid to a boil, then recombine.

Because the microwave oven energizes the food’s moisture first, there is a general drying effect: it causes moisture to evaporate out of the food. So it’s usually best to cook in a container that will retain most of the vapor around the food surface. Leave small openings for some vapor to escape, otherwise the container will burst open.

Thanks to their moisture, foods generally absorb microwaves and heat up much faster than their containers. Some ceramic containers can get very hot thanks to metal compounds in their clay or glaze. Special plastic steamers or plastic wrap are popular, but I prefer glass or ceramic ovenware, either with their own lids or with a plate on top.

Plastics are harder to clean of residual colors and flavors, and may leach undesirable chemicals into the food. They shouldn’t be used with oils or fats, which keep foods moist but can get hot enough to melt the plastic.

Despite general warnings against using metal, metal containers and aluminum foil aren’t dangerous. They reflect microwaves away from foods and so slow their heating. That’s sometimes useful for preventing the edges of foods, like fish fillets or asparagus tips, from overcooking. Just don’t put foil or bowls too close to each other or to the oven walls, since that can cause sparking.

Metal fork tines are especially likely to spark. I learned that when I melted chocolate and left a fork in the glass bowl. The whole batch tasted burned.

Microwave energy can instantly penetrate food to a depth of about an inch, instead of slowly working its way in from the surface by conduction. If the food is less than an inch thick, it’s essentially cooking all at once. That rapid heating generally means that the food retains more of its vitamins than it does when it’s boiled, steamed or baked.

On the other hand, microwave energy doesn’t build up at the surface the way ordinary heat does, so it doesn’t brown the food; its effect is more like steaming. Only when food dries out can microwaves cause browning. And that can happen out of sight, and fast.

It’s easy for nuts and stale bread (which microwaving helpfully softens for cutting) to char inside while the outside looks unchanged. The nut or bread surface stays relatively cool while the heat inside keeps building. Low oven settings can help prevent this.

Once you get used to these quirks, you’ll come up with some convenient techniques. My current favorites:

POPCORN FLAVORED WITH SPICES In conventional popping, the spices burn. Coat kernels with spices and a little oil, and zap in covered ovenware.

NON-ERUPTING POLENTA Gradual heating eases water absorption, and the polenta bubbles just as it becomes done.

HOT FOAMED MILK FOR COFFEE Put cold milk into a jar, close, and shake until foamy. Open, and microwave until hot.

One last quirk: Microwaves work in the same part of the radio spectrum as cordless phones, Bluetooth devices and wireless home networks. I’ve lost phone connections to oven interference. Sometimes that’s convenient, too.



Check Out My Other Blogs (click on blog name to go there) = / 1.3rd Eye Blog / 2. Favorites Blog/ 3. Vita Excolatur (Living Well ...) Blog/ 4. Humor Me Blog/ 5. News and Current Events Blog/ 6. Consider This ... Blog/ 7. Consumer Warnings Blog/ 8. New Orleans Pentimento Blog/ 9. We Constant Gardeners Blog/ 10. Chaillot Family Blog/

Microwave Miracles


The Minimalist

You Use It Every Day. But Can You Make It Cook?

Tony Cenicola/The New York Times

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Published: April 2, 2008

FOR years, I hadn’t used my microwave for much besides reheating leftovers and softening ice cream. I make popcorn the real way, I steam my vegetables on the stovetop, and everyone knows a potato doesn’t really bake in a microwave.

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Andrew Scrivani for The New York Times

READY THE SPOON Chocolate pudding made in a microwave oven can be served warm or cold.

Andrew Scrivani for The New York Times

A microwave curry makes good use of steamed eggplant.

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Readers shared their thoughts on this article.
Kitty, Florida

But after all, the thing is sitting there, built into my wall. You have one, too, unless it broke and you haven’t replaced it (understandable but unusual). Shouldn’t you be using it for more than reheating coffee?

I thought so, and so I decided to revisit the microwave. The push came as I was hurriedly putting together appetizers for a dinner party. I’d decided to make a combination frittata and Spanish-style tortilla (impure, I know, but they’re close enough), and it occurred to me to nuke my medium-size waxy potatoes instead of parboiling them. A few minutes in the microwave, a few minutes’ resting, peeling, then quickly browning in olive oil; I went on from there. (You can see the results, read the recipe, and check out scores of readers’ comments about microwaves on my blog.)

This success inspired me to give the thing another shot. I called Barbara Kafka, who wrote the bible “Microwave Gourmet” (William Morrow, 1987), and has devoted a portion of her life to refining her technique ever since. What did she use her microwave for most, after a quarter century of experience and experiment?

“Vegetables,” she said, without hesitation. “Their color is better, their flavor is better, you have no water dripping, and there are studies that show they retain more vitamins.”

I don’t know about the vitamins (although Harold McGee makes the same point in his article today on the science of microwaving), but in other respects, she’s right.

For any vegetable you would parboil or steam, the microwave works as well or better, and is faster. Put the vegetable in a bowl with a tiny bit of water (or sometimes none), cover and zap. Asparagus: two minutes; artichokes (a revelation): six; cauliflower (try my cauliflower with tomatoes and pimentón): five; potatoes or beets: four; spinach: one or two; eggplant: we’ll get to that. Timing, though, is tricky, especially if you strictly follow an older recipe.

“I did my original work on a 700-watt oven, which is very low power by today’s standards,” Ms. Kafka said. If you have an old oven, you can use the old times. But your current oven is probably 1,100 watts or more, which is more than 50 percent more powerful; check the label to see the wattage. So, Ms. Kafka said: “Go slowly — you can always add, but you can’t take away.”

It’s the starting and stopping, the opening and closing, that can make microwaving annoying. But Ms. Kafka is right: if you err on the side of undercooking, you can’t go far wrong. So if you’re using an older recipe, start by cutting either the time or the power in half. Take notes; they will help you the next time you make a recipe from the same source.

One of the real beauties of the oven is that when the timer goes off, the thing stops heating. You can set your asparagus for two minutes and go for a walk; when you come back it’ll be “parboiled.” Try that on top of the stove!

I was starting to think the microwave needed a new name that would reflect the thing it does best. Something like “the whiz-bang steaming oven.” Reinvigorated and inspired, I reviewed the reader suggestions I’d asked for on Bitten.

Most, not surprisingly, were for vegetables. Some went farther afield, and these I pursued with mixed and mostly unconvincing results. Toasting nuts and spices: yes, but not easier than stovetop. Poaching or scrambling eggs: fast, but unreliable beyond belief. (I have never had a harder scrambled egg.) Melting butter or chocolate: yes, but if your timing is off, you’ll make a mess and possibly burn the chocolate. “Baked” apple: a nice snack.

The microwave does a fine job on rice, saving you a pot because you can do it in your serving dish, as long as you can figure out how to set your oven so that the water doesn’t boil over, meaning you have to wash the carousel. (One-and-a-half times as much water as rice, salt, plastic wrap with a vent slit cut in it, about 12 minutes at full power.) But risotto, no, at least not for me; all the stirring makes it more trouble than it’s worth. It’s the same for chicken stock, which I’d rather make by the gallon than by the quart, thank you.

My conclusion to that point was, if you can steam it, you can microwave it. But only with vegetables was the improvement clear.

Two reader suggestions opened my eyes. A young woman from Riverdale named Mee-Lise Robinson suggested flourless chocolate cake, and a number of other readers suggested puddings. With both of those dishes, you want low heat and no crust: what would make normal cakes a failure are just what the microwave is good at.

I called Ms. Kafka again, and she said, “I don’t do desserts, except steamed puddings,” calling them a miracle. At her suggestion, I tried an old-fashioned chocolate steamed pudding. Once I’d adjusted the timing, it was just short of miraculous: easy, tender, and rich.

Finally, I recognized that many Indian desserts are pudding-like, and I called Julie Sahni to ask her opinion. Her “Moghul Microwave” (William Morrow, 1990) stands next to Ms. Kafka’s as exemplary. (Like Ms. Kafka’s, it takes things too far. But that is understandable: When we want to prove a point, we become extreme.)

“We’ve come to the point where we’re not looking at the microwave only to simplify but to find what produces the best results,” said Ms. Sahni, who lives in Brooklyn. “And when it comes to Indian pastries and desserts, it’s amazing.” She suggested I try a couple, and I did the Indian-style milk fudge. It’s not exactly my style, but I know enough about Indian desserts to recognize a success, and this was one.

Ms. Sahni also raved about upma, the polenta-like savory pudding made with semolina. Like polenta, it microwaves perfectly. But like polenta it also works perfectly, easily, and in my experience more reliably, on the stove.

If I had one single outstanding revelation, one that might change the way I cook, it was after I started messing with eggplant. One reader, Roopa Kalyanaraman — who produces her own cooking blog (www.raspberryeggplant.blogspot.com), and it’s a good one — steered me to the spicy eggplant recipe I’ve adapted here. The timing was forgiving, the recipe was easy enough, and the texture of the eggplant was mind-blowingly good, soft and not at all oily or soggy. Like steaming, but better.

I started playing, and gained some confidence. I pierced an eggplant all over and nuked it for about seven minutes, until it collapsed. While it was cooling, I gently nuked half an onion, a couple of poblanos (they collapsed too, as I’d hoped), and a couple of cloves of garlic. I peeled the eggplant, chopped it along with the onion, chilies and garlic, and tossed them with the lemon juice, a little cumin and salt: a credible eggplant salad, in short order.

Again, the results were like steaming, but with a little more whiz-bang.



Check Out My Other Blogs (click on blog name to go there) = / 1.3rd Eye Blog / 2. Favorites Blog/ 3. Vita Excolatur (Living Well ...) Blog/ 4. Humor Me Blog/ 5. News and Current Events Blog/ 6. Consider This ... Blog/ 7. Consumer Warnings Blog/ 8. New Orleans Pentimento Blog/ 9. We Constant Gardeners Blog/ 10. Chaillot Family Blog/