METHOD OF COOKING FOOD

METHOD OF COOKING FOOD

Heat transfer

In order for food to be cooked, heat must be transferred from a heat source (such as a Gas flame or an electric element) to and through the food. Understanding the ways in which heat is transferred and the speed at which it is transferred helps the cook control the cooking process. Heat is transferred in three ways: conduction, convection, and radiation. It is important to remember that, during a cooking process, more than one of these methods of Transfer may be happening at the same time. For example, food on a grill may be heated by conduction from the hot metal grill, by convection from hot air rising from the Burner or charcoal, and by radiation from the glowing burner or coals.

Conduction

Conduction occurs in two ways:

1. When heat moves directly from one item to something touching it—for example, from the top of the range to a soup pot placed on it, from the pot to the broth inside, And from the broth to the solid food items in it.

2. When heat moves from one part of something to an adjacent part of the same Item—for example, from the exterior of a roast to the interior, or from a sauté pan to its handle. Different materials conduct heat at different speeds. Heat moves rapidly through Copper and aluminium, more slowly in stainless steel, more slowly yet in glass and porcelain. Air is a poor conductor of heat.

Convection

Convection occurs when heat is spread by the movement of air, steam, or liquid (including hot fat).there is two kinds of convection:

1. Natural.

Hot liquids and gases rise while cooler ones sink. Thus, in any oven, kettle of liquid, Or deep-fat fryer a constant, natural circulation distributes heat.

2. Mechanical.

In convection ovens and convection steamers, fans speed the circulation of heat. Thus, heat is transferred more quickly to the food, and the food cooks faster. Stirring is a form of mechanical convection. Thick liquids cannot circulate as quickly as thin ones, so the rate of natural convection is slower. This explains, in part, why it is so easy to scorch thick soups and sauces. The heat is not carried away from the bottom of the pan quickly enough, so it stays concentrated on the bottom and Scorches the food. Stirring redistributes the heat and helps prevent this. (Using heavy Pots made of a material that conducts heat well also helps prevent scorching because the pot conducts the heat more quickly and evenly across the bottom and up the sides.) Convection is the process that carries the heat from the heat source to the food. Once the carrier of the heat (air or liquid) comes in contact with the food, the heat is transferred from the carrier to the food by conduction.

Radiation

Radiation occurs when energy is transferred by waves from a source to the food. The Waves themselves are not actually heat energy but are changed into heat energy when they strike the food being cooked. (Light waves, radio waves, and x-rays are examples of Radiation not used for cooking.) Two kinds of radiation are used in the kitchen:

1. Infrared.

Broiling is the most familiar example of infrared cooking. In a broiler, an electric Element or a ceramic element heated by a gas flame becomes so hot that it gives off Infrared radiation, which cooks the food. High-intensity infrared ovens are designed to heat food rapidly.

2. Microwave.

In microwave cooking, the radiation generated by the oven penetrates partway into the food, where it agitates the molecules of water. The friction this agitation causes creates heat, which cooks the food. Because microwave radiation affects only water molecules, a completely waterless material will not heat in a microwave oven. Plates become hot only when heat is conducted to them by hot foods. Because most microwaves penetrate no more than about 2 inches (50 mm) into foods, heat is transferred to the center of large pieces of food by Conduction, just as in roasting. Cooking with microwaves is discussed in more detail later in this chapter.

COOKING TIMES

It takes time to heat a food to a desired temperature, the temperature at which a food is “done” (meaning the desired changes have taken place).this time is affected by three Factors:

1. Cooking temperature.

This means the temperature of the air in the oven, the fat in the fryer, the surface of a griddle, or the liquid in which a food is cooking.

2. The speed of heat transfer.

Different cooking methods transfer heat at different rates, as shown by these Examples: Air is a poor conductor of heat, while steam is much more efficient. A jet of Steam (212°f/100°c) will easily burn your hand, but you can safely reach into a Heat and food

Oven at 500°f (260°c).this is why it takes longer to bake potatoes than to steam them. A convection oven cooks faster than a conventional oven; even if both are set at the same temperature. The forced air movement transfers heat more rapidly.

3. Size, temperature, and individual characteristics of the food.

For example: A small beef roast cooks faster than a large one. A chilled steak takes longer to broil than one at room temperature.

Fish items generally cook more quickly than meats. Because there are so many variables, it is difficult or even impossible to determine exact cooking times in most recipes. Individual ovens, fryers, and steamers, for example, May transfer heat more or less efficiently or have different recovery times. Roasting Charts that give cooking times for various cuts of meat can be used only as guidelines, and the cook must use his or her judgment to make the final determination of Doneness.

MOIST

1.   BLANCHING- Blanching means to cook an item partially and briefly, usually in water but some time oil also used.

There are two ways of blanching in water

·         Place the item in cold water brings to boil and simmer. Cool the item by plunging into in cold water.

Purpose: to dissolve out blood, salt or impurities from meat or bones.

·         Place the item in rapidly boiling water , remove and cool. Purpose : to retain the colour or destroy the harmful enzymes of vegetables or to loosen the skin of tomatoes etc.

2.   BOILING- boiling is the cooking of prepared food in a liquid at boiling point. This could be water, court bouillon, milk or stock & maintain it at that temperature.

Boiling is classified as-

·         Rapid boiling 100° C

·         Simmering is a slow, gentle, moist method of cooking in liquid or stock (85 to 96°c) simmering is best for cuts with higher amounts of connective tissue which need long, slow cooking to tenderise them.

3.   POACHING: Poaching is a wet method of cookery where food is cooked gently in liquid, which is held just below boiling point (71-82° C). Poaching liquids can be stock, stock and wine, stock syrup, milk or court bouillon (a flavoured vegetable stock). The cooking liquid adds to the taste of the finished dish and can be used to form the basis of an accompanying sauce. Poaching can be used to cook eggs, fish, chicken and certain fruits.

4.   STEAMING is a wet method of cookery that involves the preparation of foods being cooked by steam under varying degrees of pressure. Steam sometimes contacts the food directly (e.g. Vegetables) or indirectly (e.g. Covered bowls of steamed pudding). Steaming is a labour saving method of cookery. Less risk of the food drying out or burning and less risk of food overcooking. Long, slow cooking by moist heat enables the tough connective tissue in meat to convert into gelatin and the meat becomes tender. Cheaper cuts of meat can be steamed successfully. Vegetables such as root vegetables, which do not deteriorate easily in colour, flavour of texture, can also be steamed.

5.   STEWING

·         Stewing is a long, slow, wet method of cookery, which takes place in a pan with a tight fitting lid. The slow gentle cooking of tougher cuts of meat and poultry makes their texture more tender and palatable. The cooking liquid forms part of the finished dish and it is always thickened either:

·         At the start of cooking by the adding of flour to make a roux. A roux is a mixture of fat and flour to one of three stages

·         During cooking, by using ingredients such as potatoes which break down and thicken the liquid e.g. Irish stew

·         After the food has been cooked by the addition of a liaison of cream and yolks

·         The addition of a blended starch at the end of cooking.

·         Cooking can take place on top of the stove at a simmering temperature. Stewing is an economical method of cookery, as cheaper cuts of meat can be used.

·         Connective tissue and the effects of stewing

·         Meat is the muscle of animals. Muscle consists of bundles of long fibers held together by connective tissue. Older animals and muscles, which are well used, tend to produce coarser fibers and more connective tissue, yielding tougher cuts of meat. Long slow cooking in moist heat can gradually convert connective tissue into the more palatable gelatin.

6.   BRAISING

·         It is combination of roasting &stewing. It is carried out in tight fitted lid containers / casseroles. Braising is done to prevent the loss of juices due to evaporation. It is long cooking method & normally takes 5-6 hrs.

·         Methods of braising

·         Brown braising

·         Use for joints & portion sized cuts of meat.

·         Meat sealed by browning in hot oven / pan on the stove

·         Sealing helps in retain flavour, nutritive value & gives a good colour.

·         Meat then placed on a bed of root vegetable in a braising pan, with liquid, covered with a lid & cooked slowly.

·         White braising

·         Use for vegetable & sweet breads

·         Foods are blanched, refreshed cooked on a bed of root vegetable.

·         Use white stock, cooked slowly

FAT

1.   FRYING

·         SHALLOW FRYING is a fast, fat method of cookery. Shallow frying is the cooking of food in a small-preheated fat or oil on a hot surface such as:  A frying pan or a solid cooking surface such as a griddle. When this type of cooking equipment is used the process is known as griddling. Some griddles have grooved surfaces to mark the food, improving the appearance. The coating of oil (or fat) prevents the food from sticking and helps conduct the heat to the foods surface.

·         STIR FRYING is a popular method of cookery and is a variation of shallow frying. Food is cooked and stirred very quickly in a wok. Sautéing is tossing the food in the pan during cooking so that it cooks and browns on all sides e.g. Sauté potatoes. The word sauter is actually taken from the french verb sautoir, which means to “jump”.

·         Meunière. This is a traditional french way to cook fish. The fish is passed through seasoned flour, shallow fried and finished with nut-brown butter, chopped parsley and lemon juice.

·         Deep fat frying is a fast fat method of cookery where food is cooked by submerging it in preheated fat or oil. The oil or fat is heated to a temperature of 165°- 190° (320°to 375°f). The food is cooked quickly and its surface browns and develops a crisp texture. The temperature of the oil is an essential factor if deep fried food is to be palatable. Preheating the oil to the recommended temperature will allow the outside of the food to be seared and coloured. Fried foods always absorb carrying various amounts of oil, depending upon the type of food and the initial temperature of the fat. This fat absorption can vary from 5% to 40% so control of temperature is crucial to prevent excessive absorption resulting in greasy food. Draining the fried food on kitchen paper after frying will also help to remove any excess fat, making the dish more appealing.

Coatings

·         Coatings are used on some foods before deep-frying. Coatings help to:

·         Reduce the fat absorption

·         Improve the shape

·         Assist the browning

·         Improve the texture.

Types of coatings are:

·         Flour -

·         Breadcrumbs –

·         Batter

2.   ROSTING: Roasting is a most preferred method of cooking used in western cookery as it is used for prime cuts of meats. No liquid is added to the meat so original meat flavour can come.  Roasting is cooking in dry heat with the aid of fat or oil in an oven or on a spit.

·         Pot roasting: it is carried out in covered in covered pot or pan. Good quality meat item / smaller joints are used. Meat / game / poultry is kept on the skewers to avoid sticking to the bottom. Lid should be covered and the bird should be basted regularly. Cooking should be done on slow fire. Root vegetables should be put after 20 min. To get flavour. When the joint is cooked, add stock so that the vegetable mix and form an accompaniment called as jus-lie gravy.

·         Oven roasting: cooking is done in the roasting trays. Meat / poultry and certain vegetables are used. Joints can be trimmed and tied if retaining of shape is necessary. Joints can be browned to seal the pores and cooking time is 15 min. For 455 grams. Of meat and another 15 min. In oven.

·         Spit roasting:  here a spit is constantly revolved to ensure evenly colouring. It is cooking by direct heat and basting is carried out regularly.

·         Tandoor roasting: it is carried out in tandoor by using is carried out regularly.

Terms related to roasting

·         Pôeling: it is similar to pot roasting except for the thing that in this method butter is used instead of fat as cooking medium.

·         Encasserole: it is same as pôeling but no vegetables is used in this method. Only brown stock can be poured.

·         Encocotte: same as pot roasting except that the food items is garnished with the vegetables which are cooked in butter.

3.   GRILLING   this is fast medium of cooking by direct heat. Sometimes known as broiling. It is earliest method of cooking & also gives the variety to the menu.

Over heat:

·         (charcoal, bar-be-que, gas or electric grill)

·         Bars must be preheated

·         Food starts from hottest part then move to cooler part of the grill.

·         Cooking time depends on the thickness of the food & heat.

Under heat: (salamander)

·         Should be pre-heated & greased.

·         Soft items grilled on tray.

·         Salamander can be used for browning, gratinating & glazing.

Between heat:  grilling between electrically heated grill bars.

Degree of cooking

·         Rare                      :                  au bleu

·         Underdone           :                  saignant

·         Just done             :                  a point

·         Well done              :                  biencuit

DRY

1.   Baking:  it is a cooking of food by dry heat in an oven. Degree of dryness can be modified from the amount of steam produced from the item.

·         Dry baking: when baking, steam arise from the water content of the food, this steam combines with the dry heat of the oven to cook the food. (Cake, pastry)

·         Baking with increased humidity: when baking certain food in oven, with increased humidity by placing a bowl of water.

·         Baking with heat modification: placing food in container of water, (bein marie) modifies the heat so that the foods cook slowly.

2.   Broiling: it is dry form of cooking & carried out on iron bars or pan. Beef & fish are broiled; even spices are broiled on hot griddle to bring out their flavour.