Understanding Heat in Cooking

OF all the ingredients in the kitchen, the most common is also the most mysterious.

It’s hard to measure and hard to control. It’s not a material like water or flour, to be added by the cup. In fact, it’s invisible.

It’s heat.

Every cook relies every day on the power of heat to transform food, but heat doesn’t always work in the way we might guess. And what we don’t know about it can end up burning us.

We waste huge amounts of gas or electricity, not to mention money and time, trying to get heat to do things it can’t do. Aiming to cook a roast or steak until it’s pink at the center, we routinely overcook the rest of it. Instead of a gentle simmer, we boil our stews and braises until they are tough and dry. Even if we do everything else right, we can undermine our best cooking if we let food cool on the way to the table — all because most of us don’t understand heat.

Heat is energy. It’s everywhere and it is always on the move, flowing out as it flows in. It roils the chemical innards of things, exciting their molecules to vibrate and crash into each other. When we add a lot of heat energy to foods, it agitates those innards enough to mix them up, destroy structures and create new ones. In doing so it transforms both texture and flavor.

There are, however, uncountable ways to misapply heat. In most cooking, we transfer energy from a heat source, something very hot and energetic, to relatively cold and inert foods. Our usual heat sources, gas flames and glowing coals and electrical elements, have temperatures well above 1,000 degrees Fahrenheit(537 C). Boiling water is around 212 degreesF (100 C).

Cooks typically heat food to somewhere between 120 degrees F(50C) (for fish and meats that we want to keep moist) and 400 degrees F(205 C) (for dry, crisp, flavorful brown crusts on breads, pastries, potatoes, or on fish and meats).

At the bottom of that range, a difference of just 5 or 10 degrees can mean the difference between juicy meat and dry, between a well-balanced cup of coffee or tea and a bitter, over-extracted one. And as every cook learns early on, it’s all too easy to burn the outside of a hamburger or a potato before the center is warm.

That’s the basic challenge: We’re often aiming a fire hose of heat at targets that can only absorb a slow trickle, and that will be ruined if they absorb a drop too much. Are you ever annoyed by pots that take forever to heat up, or frustrated by waiting for dry foods to soften? A kitchen that becomes hot enough to be a sauna? Big jumps in the utility bill when you do a lot of cooking? The problem, as you will notice if you pay more attention to your kitchen’s thermal landscape, even in terms of what you can feel, is how much heat escapes without ever getting into the food.

Among the major culprits here are inefficient appliances, a gas burner delivers only 35 to 40 percent of its heat energy to the pan; a standard electrical element conveys about 70 percent. Anyone thinking about kitchen renovation should know that induction cooktops, which generate heat directly within the pan itself, are around 90 percent efficient. They can out-cook big-B.T.U. gas burners, work faster, don’t heat up the whole kitchen, and are becoming more common in restaurant kitchens.

Maximizing the transfer of heat from burner to pot produces better food. In deep frying, the faster the burner can bring the oil temperature back up after the food is added, the quicker the food cooks and the less oil it absorbs. In boiling green vegetables, a fast recovery time means better retention of vibrant color and vitamins.

No matter how efficient an appliance is, the cook can help simply by covering pots and pans with their lids. Some of the heat that enters through the bottom of the pot exits through the top, but a lid prevents much of it from escaping into the air. This is especially true when you’re bringing a pot of water to the boil. With the lid on, it will start bubbling in as little as half the time. Turning water into steam takes a lot of energy, and every molecule that flies away from the water surface takes all that energy with it into the air. Prevent its escape, and the energy stays with the pot to heat the rest of the water.

Once a liquid starts to boil and is turning to steam throughout the pot — the bubbles of a boil are bubbles of water vapor — nearly all the energy from the burner is going into steam production. The temperature of the water itself remains steady at the boiling point, no matter how high the flame is underneath it. So turn the burner down. A gentle boil is just as hot as a furious one.

Cooking doesn’t get much more straightforward than boiling and steaming vegetables, grains, and the like. But sometimes it takes forever, which either delays dinner or results in crunchy beans and diners suffering for it later. And you can’t speed the process by raising the heat.

In fact it’s easy to save loads of time and energy and potential discomfort with grains, dry beans and lentils, and even pasta. But it requires a little thinking ahead. It turns out that the most time-consuming part of the process is not the movement of boiling heat to the center of each small bean or noodle, which takes only a few minutes, but the movement of moisture, which can take hours. Grains and dry legumes therefore cook much faster if they have been soaked. However heretical it may sound to soak dried pasta, doing so can cut its cooking time by two-thirds — and eliminates the problem of dry noodles getting stuck to each other as they slide into the pot.

The trickiest foods to heat just right are meats and fish. The problem is that we want to heat the center of the piece to 130 or 140 degrees F(55-60 C), but we often want a browned, tasty crust on the surface, and that requires 400 degrees(205 C).

It takes time for heat to move inward from the surface to the center, so the default method is to fry or grill or broil and hope that the browning time equals the heat-through time. Even if that math works out, the area between the center and surface will then range in temperature between 130 and 400 degrees(55-205 C). The meat will be overcooked everywhere but right at the center.

The solution is to cook with more than one level of heat. Start with very cold meat and very high heat to get the surface browned as quickly as possible with minimal cooking inside; then switch to very low heat to cook the interior gently and evenly, leaving it moist and tender.

On the grill, this means having high- and low-heat zones and moving the food from one to the other. On the stove top or in the oven, start at 450 or 500 degrees F(230-260 C), and then turn the heat down to around 250 F (120 C), ideally taking the food out until the pan or oven temperature has fallen significantly.

Another solution is to cook the food perfectly with low heat, let it cool some, and then flavor its surface with a brief blast of intense heat from a hot pan or even a gas torch. More and more restaurants are adopting this method, especially those that practice sous-vide cooking, in which food is sealed in a plastic bag, placed in a precisely controlled water bath and heated through at exactly the temperature that gives the desired doneness.

All these are two-step processes, but the same principle works for three steps or more. Rotisserie cooking alternates high and low heat many times: as the meat turns on the spit, each area of the surface is briefly exposed to high browning heat, then given time for that dose of energy to dissipate, part of it into the meat but part back out into the cool air. So the meat interior cooks through at a more moderate temperature. Similarly, steaks and chops cook more evenly on high grill heat — and faster as well — if you become a human rotisserie and turn them not once or twice but as often as you can stand to, even dozens of times, every 15 or 30 seconds.

Tough cuts of meat require longer cooking to dissolve their connective tissue, and stewing or slow braising in a low oven is a simple and popular method of doing so. But many recipes don’t give the best results, simply because they don’t take into account the vast difference between cooking with the lid on and off. Even in an oven set as low as 225 or 250 degrees F(110-120 C), if the pot is covered, the contents will reach the boil, and the meat will overcook and dry out.

Leave the lid ajar or off, and evaporation of the cooking liquid cools the pot and moderates the meat temperature, keeping it closer to 160 to 180 degrees F(70-80 C). This is hot enough to soften the connective tissue in a few hours without also driving out most of the meat’s moisture.

The challenge of heat management doesn’t end when you’ve cooked something to perfection. How often have you found that the dish that was perfect in the kitchen seems to have lost something by the time you sit down and take the first bite? That something certainly includes heat.

Heat knocks molecules at the surface of food into the air where we can sniff them, so it increases the aroma. Inside the food, agitated molecules make sauces more fluid and hot meat more tender. And the sensation of a food’s warmth is satisfying in itself. The moment hot food is put on a plate, its heat energy begins to flow out into the cooler surroundings. Aromas fade, sauces thicken, fats congeal.

So when you transfer heat’s handiwork from the kitchen to the table, take along some extra. Warm the plates to prolong the pleasure. And encourage everyone to sit down and eat it while it’s hot.

Nutria from rat like pest to delicacy,if you can’t beat them,eat them-Recipies

It’s another in a long line of scamps and scalawags, pirates and privateers who have profited in Louisiana while the state suffered.
This outsider is straining Louisiana’s traditional tolerance of scoundrels. Its gluttony is laying waste to the southern half of the state.
Previous troublemakers have been called dirty rats or even weasels. This new marauder is, in fact, a member of the rodent family. It’s a nutria: a nearsighted, ratlike South American import that for 60 years has been reproducing wildly and flourishing in the Louisiana wetlands, all the while eating all the vegetation it could get past its pronounced overbite.Nutria are large, web-footed rodents that are more agile in the water than on land. They live in burrows, or nests, never far from the water. Nutria may inhabit a riverbank or lakeshore, or dwell in the midst of wetlands. They are strong swimmers and can remain submerged for as long as five minutes.
Nutria (also called coypu) are varied eaters, most fond of aquatic plants and roots. They also feast on small creatures such as snails or mussels.
Nutria can be rather social animals and sometimes live in large colonies, reproducing prolifically.
Nutria - several million of them, officials estimate - are destroying the coastal wetlands that are crucial to Louisiana’s water-control efforts, vital to the fishing and trapping industries and home to scores of protected species.
Experts are stumped
Environmental and wildlife experts have for decades been stumped at how to rid the swamps and bayous of the creature, whose rampant feeding threatens to destroy a buffer zone for hurricanes sweeping in from the Gulf of Mexico.
Now the state is striking back. Officials with the Wildlife and Fisheries Department have begun a five-year program aimed at downsizing the nutria population and reclaiming denuded wetlands by tapping into what people in Louisiana do exceedingly well: eat.
Officials have recruited the state’s top chefs to create dishes to entice citizens to devour nutria. They hope they can saute, braise and fricassee their way out of this crisis.
Not much choice
They have tried other approaches, and they haven’t worked,they don’t have much choice at this point.
So far it’s been a tough sell. People here may be famous for their adventurous eating habits, but they appear to have drawn the nutritional line at nutria. Call it what you want, it still looks like a rat.
The environmental problem grew out of the ruthlessness of the nutria’s eating habits. It treats the Mississippi Delta as its personal salad bar. It feeds by paddling around a heavily vegetated marsh and seeks out the tender roots of aquatic plants, chewing its way up to the leaves, which it ignores. Biologists call the damaged sections “eat-outs.”
They eat only 10 percent of what they destroy,ninety percent of the plant floats away.
Replanting has been tried on a limited basis, with little success. Nutria follow behind, eating the tender shoots of the new plants. Even when they aren’t eating, nutria burrow into levees, causing them to collapse.
They are strong swimmers. Adults grow to about the size of a small beaver, propelling themselves with webbed back feet and steering with their rope-like tail. Their vegetarian diet provides little fuel, so nutrias must eat constantly.
When they aren’t eating, they have one other major interest. Nutria’s mating habits make rabbits seem standoffish. They begin breeding at six months and have three litters a year, with up to 13 offspring in each litter.
One natural population control in Louisiana is the alligator, which is happy to include nutria in its diet but is dormant four months a year.
Fur-industry plans failed
Louisiana’s nutria were brought from South America in the 1930s, but hopes of establishing a fur industry failed. At one point, officials estimated there were 20 million nutria in the state, but the current population may be half of that.
They have popped up elsewhere in the country - including Oregon’s Willamette Valley - but nowhere else on this scale.
Louisiana officials began the new nutria-control program, which got under way this year, as a response to the damage to what they conservatively estimate is 80,000 acres of coastal wetlands. Forty percent of the nation’s coastal wetlands lie in Louisiana, where 80 percent of the total national wetland loss occurs.
If the population is not controlled, thousands of acres of wetlands are in serious jeopardy.
If you can’t beat them,eat them
Officials would like nutria to join blackened redfish and alligator meat as part of Louisiana’s must-have cuisine. They are spending $2 million to develop a market for a meat that has been tested as highly lean, low in cholesterol and rich in protein.
The key to the program is to add incentive for nutria harvesting. The state will essentially subsidize the hunting and processing of nutria meat.
There is only one licensed nutria processor in the state, Tommy Stoddard of Hackberry. He says the animal is difficult to dress and takes a trained person five minutes to clean. He has processed about 5,000 pounds of nutria meat this year.Before there is a steady supply of meat, there must be a demand. That’s where chef Philippe Parola comes in. He directs the Louisiana Culinary Institute in Jackson and the man responsible for developing enticing nutria recipes.
At his restaurant he offers nutria fettuccine, marinated nutria salad, nutria “a l’orange, culotte de” nutria “a la moutarde” and, for the health conscious, heart-healthy crockpot nutria. Parola was dispatched to Japan in March to test the waters for the product. “Look, I am French, I know about eating odd things,” Parola said. “I would like to meet the chef who first went outside, picked up a snail, cooked it, put it on a table in front of someone and said, `This is snail. Eat it.’ ”
Enola Prudhomme, owner and chef at Prudhomme’s Cajun Cafe and the sister of the fabled Paul Prudhomme, has developed her own recipes. “It’s difficult to get, but I can sell it when I do have it. Mostly it’s the tourists who want it; they also want the alligator. It’s the `Louisiana experience,’ I guess.”
The chefs report that when they can lure anyone to try nutria, they like it. The tender meat tastes like rabbit, it is said. But it’s getting anyone to take the first bite that’s difficult.

Looks like a well-fed rat
It’s also a rat issue. Because nutria is so well known in Louisiana, people are familiar with what they look like. Naturalists may say they are closely related to the guinea pig, but to the untrained eye, a nutria looks like a well-fed rat.
That’s why Lousiana officials have high hopes for the foreign market. People will never see the nutria, just the processed meat.
State officials dream of a time in the not-so-distant future when, all over the world, it will be common to hear: “Nutria? Very good. How about a nice chardonnay to go with it?
Heart Healthy Crock Pot Nutria
2 hind saddle portions of nutria meat
1 tomato, cut in big wedges
2 carrots, sliced thin
1/2 cup white wine
2 teaspoons chopped garlic
1 cup demi glace (optional)
1 small onion, sliced thin
2 potatoes, sliced thin
Brussel sprouts
1 cup water
salt and pepper to taste
Layer onion, tomato, potatoes, carrots and Brussel sprouts in crock pot. Season nutria with salt, pepper and garlic to taste and place nutria over vegetables. Add wine and water, set crock pot on low and let cook until meat is tender. Cook for approximately 4 to 6 hours. Garnish with vegetables and demi glace (4 servings)
Nutria Hind Saddle with Mustard Sauce
2 hind saddles of nutria
2 tablespoons Dijon mustard
1/3 cup chopped celery
1/3 cup chopped onion
2 tablespoons vegetable oil
1/3 cup chopped carrots
3 teaspoon Tony Chachere's seasoning
1/2 teaspoon crushed rosemary
1 cup white wine
1 cup water
Place oil, celery, onions and carrots in a pan; set aside. Rub each hind saddle with one teaspoon Tony Chachere's seasoning, two tablespoons Dijon mustard and 1 1/2 teaspoons rosemary. Place hind saddles on top of other ingredients in the pan. Place uncovered in a 350 degree oven for 15 minutes.
Remove from oven and add one cup white wine with water to the pan to a depth of 1/4 inch. Cover pan with plastic wrap, then cover again with aluminum foil. Place back in the oven for 45 minutes to an hour. (Until well done). Use drippings for sauce. Serves 4
Ragondin a l'Orange
2 hind saddle portions nutria meat
1/2 cup brown sugar
1 cup orange juice
2 tablespoons vegetable oil
2 cups white wine
1 tablespoon Soya sauce
orange zest, minced
salt and pepper to taste
Mire Poix:
1/3 cup chopped celery
1/3 cup chopped carrots
1/3 cup chopped onion
Bouquet Garni:
1 bunch fresh thyme
1 bunch parsley
bay leaves
Place oil, mire poix and bouquet garni in a pan; set aside. Rub each hind saddle with brown sugar and salt and pepper to taste. Place saddles on top of other ingredients in pan. Place, uncovered, in a 350-degree oven for 15 minutes.
Remove from oven and deglaze with white wine, Soya sauce and orange juice. Cover pan with plastic wrap, then cover again with aluminum foil. Place back into oven for 45 minutes to one hour until meat is tender. Break meat off bones. Place on plate then garnish with vegetables, sauce from pan drippings and orange zest. Makes 4 servings.
Nutria Fettuccini
Mire Poix:
1 chopped onion
1 chopped carrot
1 chopped celery stick
2 cloves garlic
Bouquet Garni:
1 whole clove
1/2 bunch parsley
4 black peppercorns
Pasta:
2 lbs. cooked fettuccini
3 mushrooms, sliced
1 clove garlic
fresh spinach to taste
1 tablespoons sun-dried tomatoes, minced
2 tablespoons olive oil
parmesan cheese to taste
1 red bell pepper, minced
Nutria
1 hind saddle nutria
2 quarts cold water
1 cup red wine
salt and pepper to taste
1 teaspoon red wine vinegar
1 teaspoon Louisiana hot sauce
Bring water, seasonings, mire poix and bouquet garni to a boil. Add nutria meat and simmer for 1 hour or until tender. Remove meat and break meat off bones. Discard any gristle or silver skin.
With olive oil sauté garlic, sun-dried tomatoes, mushrooms, bell peppers and spinach for 3 to 4 minutes. Then add nutria meat and sauté for 3 minutes until hot. Add fettuccini, sauté and serve, topped with parmesan. Makes 4 servings.
SMOTHERED NUTRIA
Makes 4 Servings
2 tablespoons vegetable oil
1-3 pound nutria, cut in serving pieces
2 tablespoons Enola's Secret Seasoning + 2 teaspoons
2 cups finely chopped onion
1 cup finely chopped green bell pepper
1 tablespoon flour
1 teaspoon salt (opt.)
3 3/4 cups chicken stock or broth
In a heavy 5-quart pot on high heat, add oil, heat until very hot. Sprinkle seasoning on meat; stir well. Add meat to pot, brown on all sides. Cook and stir 10 minutes. Add onion, bell pepper and flour, cook and stir 10 minutes. Add salt and chicken stock to pot cook and stir occasionally, (about 15 minutes) scraping the bottom of pot to remove all the goodness. Serve over hot cooked rice, pasta or cream potatoes.