Jim Coleman: How hot is too hot?: You can figure out when a pan or grill is ready to cook food

Q: A lot of recipes begin with preheating a pan to various temperatures such as low, medium low, medium, medium high, etc. Most grilling recipes have the same instructions. How do you determine the heat of a preheated frying pan or grill? Is preheating a saute pan really necessary?

- Christian M.

A: When it comes to preheating a pan for a recipe, learning how to gauge the correct heat can be tricky. An easy way to tell if your pan's too hot is if it starts smoking as soon as you add the oil or fat. Then, when you add the food, it immediately sears, burns and catches on fire. In the business, we call that "too high."

First, let's answer your question about why we preheat pans. There are lots of reasons, some of which aren't as important as they used to be.

A long time ago (I know most of you think I am speaking from memory), most pans were made of cast iron, which is very porous. The trick was to heat the pans on the stove to close the "pores." This turned them into almost non-stick pans so that, after oil was added, food cooked in these pans wouldn't act like it was glued to the bottom.

Also, most pans have hot spots, so heat is not universally distributed as the pan warms. This uneven allocation of heat factors occurs even more with electric stoves.

One exception here is using copper pans, which are great conductors of heat. But the price of copper is almost as high as gasoline, so I'm guessing that people whose kitchens are lined with copper pans also have personal chefs who don't need my advice.

For the rest of you, preheating your pans will allow the heat to disperse throughout the bottom and not just to the hot spots. We all know what happens when we have hot spots: One part of the dish gets beyond crispy - OK, it's burnt - while other parts may be underdone.

When a recipe calls for medium-high or high heat, it's asking you to sear the product in a very hot pan, very quickly.

If you start with a cold pan, the food will release its natural juices before it gets hot. By the time the pan heats up, the food will be boiling in its own juices, which makes for a very tough, colorless dish. This is why 95 percent of all recipes have you cook over high heat in a hot pan.

The main reason a recipe would tell you to begin with a cold pan is for the purpose of rendering fat. A good example of this would be cooking a boneless, skin-on duck breast.

We all know that duck skin is very fatty, so putting it into a cold pan will naturally render fat as the pan heats up. If we put the duck breast into a hot pan, it would sear the pores and keep the fat in.

Now let's talk about heating up a grill.

When you're cooking with wood or charcoal, you always want to burn down to the embers before you add food. A gas grill should be on high heat for at least 10 to 15 minutes with the lid down. This will not only get your grill nice and hot, it also will sanitize the grill grates. Then adjust to the desired heat for the food you are cooking.

Here is a rule of thumb to determine how hot your grill is, assuming you haven't already burned your thumb off.

But first, time out for our lawyers. We are not as serious as the Lazer Yo-Yo Company, whose disclaimers included: "1. To prevent choking, don't put yo-yo into mouth. 2. Don't tie the string around neck to play in a rough way."

Instead, Christian, we have the following disclaimer from the law firm of Dewey, Cheetham and Howe: Use your head, and be careful!!

Anyway, if you can hold your hand two inches over a grill for two seconds, this is high heat; three seconds is medium-high; four seconds, medium; and five seconds, low.

This same method applies for testing the heat of a saute pan, but you add three seconds per level of temperature. To do this test, you want to get as close to the pan as possible without touching it. Because even a pan that's on low heat is still on the heat.

Here's another tip:

Years ago, while speaking with a fire chief, he explained to me that the best way to handle a fire is to remove things from its environment: remove the heat, fuel and oxygen. Now, we also remove the chef as well.

CHARRED ASPARAGUS SALAD WITH TOMATO

AND MIXED GREENS

1 tablespoon olive oil

2 tablespoons red wine vinegar

1/4 cup low-sodium chicken stock

1 teaspoon minced shallots

1 teaspoon sugar

1 tablespoon finely sliced fresh chives

20 asparagus spears

4 ounces mixed baby salad greens

1 tomato blanched, peeled, seeded and chopped

Place the oil, vinegar, chicken stock, shallots, sugar and chives in a blender and process until emulsified. Set the dressing aside.

Trim the asparagus, discarding the thick ends. Spray a non-stick pan with cooking spray, and place it over high heat. When the pan is hot, add about 10 asparagus spears and saute for 4 to 5 minutes, until charred on all sides. Repeat for remaining asparagus. (Or the asparagus can be charred on a hot outdoor grill.)

Place the greens in a mixing bowl and toss with three-quarters of the vinaigrette. Place a small mound of the dressed greens at the top of each plate. Fan out the asparagus over the bottom portion of the plate, with the ends slightly touching the greens. Sprinkle the remaining vinaigrette over each plate and garnish with the chopped tomato. Serves 4.

Chef Jim Coleman, corporate chef at Normandy Farm and Blue Bell Country Club, is the author of three cookbooks and hosts two nationally syndicated shows: "A Chef's Table," noon Saturdays on WHYY (91-FM); and "Flavors of America," 1 p.m. Saturdays on Channel 12, and 4:30 p.m. weekdays on CN8. He and his wife, writer Candace Hagan, will answer questions.

E-mail ChefColeman@aol.com.