Steamy

According to conventional wisdom, there are two types of cooking: wet, as in boiling, and dry, as in baking. But cooking isn’t always so wet and dry.

Consider steaming. In some ways it’s wet. In others, dry.

What’s going on? Perhaps a little cook’s chemistry will help.

There are really two primary types of foods that are cooked: proteins (usually meats) and starches (usually vegetables). They behave in very different ways.

Proteins exist as strands, and when they are heated, they tighten. That’s why a piece of meat feels harder and harder the longer it’s cooked (up to the point that the molecules are so tightly wrapped that they actually break). Like a damp towel, the tighter it’s wrung, the more moisture it loses. That’s why turkey breast sometimes has the texture of face powder.

Starches are more like granules, and they swell when heated. Like a balloon, when they swell too much, the cell walls can no longer hold their contents and they break. An extreme example would be when soup vegetables cook to the point that they literally fall apart.

Wet cooking and dry cooking differ in two primary ways, and it all comes down to the cooking medium.

Let’s take wet cooking first. Because boiling water will never reach a temperature of more than 212 degrees and food doesn’t begin its browning process until 240 degrees, that delicious development of secondary flavors we call the Maillard reaction never takes place.

The cooking medium also makes a difference because as those starch molecules (and ultimately even protein molecules) start to burst, fluids begin to exchange between the thing being cooked and the liquid in which it’s being cooked. That’s the secret behind soups and stocks.

In dry cooking, on the other hand, the temperature can be much higher. (Why, then, can you can stick your hand in a 450-degree oven but not in a 212-degree pot of boiling water? Ask your physics teacher.) This allows the development of the browning flavors.

On the other hand, once those roasted molecules swell and the strands break, there is no liquid to be absorbed. It’s a one-way street: Juices go out but there’s nothing to come back in.

What about steaming? First, the temperature never gets beyond 212 degrees (well, it does, but just barely), so the browning reaction never starts. On the other hand, there is no immersing liquid to exchange flavors with (again, there’s a little, but only the trace that actually condenses on the food).

The bottom line is that you have food that tastes almost exclusively of itself. Any flavors you want beyond that will have to be added, either by marination beforehand or by seasoning afterward.

Otherwise, whether you like steaming pretty much depends on how you feel about the phrase “plain steamed vegetables.”

MARINATED BELL PEPPERS

This recipe is from Stephanie Lyness’ book “Cooking With Steam” (Hearst Books, 1996, $19.95). Lyness uses red and yellow peppers not because they taste better than green but because they are easier to peel. Serve the peppers as a side dish or with goat or feta cheese in a sandwich, pouring the flavored oil over the bread.

2 red bell peppers, halved, cored, seeded and ribs removed

2 yellow bell peppers, halved, cored, seeded and ribs removed

1 tablespoon balsamic vinegar

1/4 cup olive oil

4 to 6 basil leaves, torn in pieces

1/2 teaspoon chopped fresh thyme or 1/4 teaspoon dried, crushed

1/8 teaspoon freshly ground black pepper

Put pepper halves in steaming basket, cover and steam 25 to 30 minutes. Remove from steam and let stand until cool enough to handle.

Peel off pepper skins with fingers. Tear peppers lengthwise into strips about 1 inch thick (they tear naturally along visible lines in flesh) and put in shallow baking dish. Add vinegar, oil, basil, thyme and black pepper and toss to coat. Cover and refrigerate overnight.

2 to 3 servings. Each of 3 servings:

210 calories; 3 mg sodium; 0 cholesterol; 18 grams fat; 12 grams carbohydrates; 2 grams protein; 0.26 gram fiber.

* Rebecca Wood pottery bowls from Zero Minus Plus, Santa Monica.