Transcript
Different Cooking Methods FACT SHEET
Deep frying is a cooking method in which food is submerged in hot oil or fat. This is normally performed with a deep fryer or chip pan; industrially, a pressure fryer or vacuum fryer may be used. Deep frying is classified as a dry cooking method because no water is used. Due to the high temperature involved and the high heat conduction of oil, it cooks food extremely quickly
Stir frying is an umbrella term used to describe two techniques for cooking food in a wok while stirring it. The term stir-fry was introduced into the English language by Buwei Yang Chao, in her book How to Cook and Eat in Chinese, to describe the chǎo technique. The two techniques differ in their speed of execution, the amount of heat used, and the amount of tossing done to cook the food in the wok. Cantonese restaurant patrons judge a chef's ability to perform stir frying by the "wok hei" produced in the food. This in turn is believed to display their ability to bring out the qi of the wok.
Steaming Method Steaming works by boiling water continuously, causing it to vaporize into steam; the steam then carries heat to the nearby food, thus cooking the food. The food is kept separate from the boiling water but has direct contact with the steam, resulting in a moist texture to the food. This differs from double boiling, in which contact with steam is undesired. Such cooking is most often done by placing the food into a steamer, which is typically a circular container made of metal or bamboo. The steamer usually has a lid that is placed on the top of the container during cooking to allow the steam to cook the food. When a steamer is unavailable, a wok filled less than half with water is a replacement by placing a metal frame made of stainless steel in the middle of the wok. Some modern home microwave ovens include the structure to cook food by steam vapor produced in a separate water container, providing a similar result to being cooked by fire. Benefits Overcooking or burning food is easily avoided when steaming it. Health conscious individuals may prefer steaming to other methods which require cooking oil, resulting in lower fat content. Steaming also results in a more nutritious food than boiling because fewer nutrients are leached away into the water, which is usually discarded? comparison between steaming and boiling vegetables shows the most affected nutrients are folic acid and vitamin C. Compared to raw consumption, steaming reduces folic acid by 15%, and boiling reduces it by 35%. Again compared to raw consumption, steaming reduces vitamin C by 15%, and boiling reduces it by 25%. Phenolic compounds with antioxidant properties
have been found to retain significantly better through steaming than through boiling or microwaving. Most other nutrients are reduced by a similar amount by both methods of cooking.
Blanching is a cooking term that describes a process of food preparation wherein the food substance, usually a vegetable or fruit, is plunged into boiling water, removed after a brief, timed interval, and finally plunged into iced water or placed under cold running water (shocked) to halt the cooking process. The meaning of blanching is "to whiten", but this is not always the purpose of blanching in cooking. Food is blanched to soften it, or to partly or fully cook it, or to remove a strong taste (for example of bacon, cabbage, or onions). When almonds or pistachios are blanched, the skin of the nut (botanically the seed coat surrounding the embryo) becomes softened by blanching and is later removed. The technique of blanching vegetables is best illustrated by the requirement to stop cook asparagus, otherwise it would become soggy due to the asparagus continuing to cook after it is removed from the boiling water. To cook asparagus using the blanching method, the shoots are boiled for 30 seconds, and then to stop the cooking instantly they are dipped into cold or ice water. The term "blanched asparagus" is also used for white asparagus. White asparagus is produced by a special gardening technique; one first covers the young preemerging shoots with a paper bag to block out light and cause the unexposed white shoots to grow without chlorophyll (some of the shoots from the plant must remain in sunlight and turn green, to keep the plant healthy).
A stew is a combination of solid food ingredients that have been cooked in liquid and served in the resultant gravy. Ingredients in a stew can include any combination of vegetables (such as carrots, potatoes, beans, peppers and tomatoes etc.), meat, especially tougher meats suitable for slow-cooking, such as beef. Poultry, sausages, and seafood are also used. While water can be used as the stew-cooking liquid, wine, stock, and beer are also common. Seasoning and flavourings may also be added. Stews are typically cooked at a relatively low temperature (simmered, not boiled), allowing flavors to mingle. Stewing is suitable for the least tender cuts of meat that become tender and juicy with the slow moist heat method. This makes it popular in low-cost cooking. Cuts having a certain amount of marbling and gelatinous connective tissue give moist, juicy stews, while lean meat may easily become dry. Stews may be thickened by reduction or with flour, either by coating pieces of meat with flour before searing, or by using a roux or beurre manié, a dough consisting of equal parts of butter and flour. Thickeners like cornstarch or arrowroot may also be used.
Stews are similar to soups, and in some cases there may not be a clear distinction between the two. Generally, stews have less liquid than soups, are much thicker and require longer cooking over low heat. While soups are almost always served in a bowl, stews may be thick enough to be served on a plate with the gravy as a sauce over the solid ingredients.
For roasting, the food may be placed on a rack, in a roasting pan or, to ensure even application of heat, may be rotated on a spit or rotisserie. During oven roasting, hot air circulates around the meat, cooking all sides evenly. There are several theories for roasting meats correctly: low-temperature cooking, high-temperature cooking, and a combination of both. Each method can be suitable under the appropriate circumstances. A low-temperature oven, 95°C to 160°C (200°F to 325°F), is best when cooking with large cuts of meat, turkey and whole chickens. This is not technically roasting temperature, but it is called slow-roasting. The benefit of slow-roasting an item is less moisture loss and a more tender product. At true roasting temperatures, 200°C (400°F) or more, the water inside the muscle is lost at a high rate. Cooking at high temperatures is beneficial if the cut is small enough (filet mignon, strip loin) to be finished cooking before the juices escape. The combination method uses high heat just at either the beginning or the end of the cooking process, with most of the cooking at a low temperature. This method produces the golden-brown texture and crust, but maintains more of the moisture than simply cooking at a high temperature, although the product will not be as moist as low-temperature cooking the whole time. Searing and then turning down to low is also beneficial when a dark crust and caramelized flavor is desired for the finished product. Note that searing in no way "locks in" moisture – moisture loss is simply a function of heat and time. In general, in either case, the meat is removed from heat before it has finished cooking and left to sit for a few minutes, while the inside cooks further from the residual heat content, a phenomenon known as carry over cooking. The objective in any case is to retain as much moisture as possible, while providing the texture and color. During roasting, meats and vegetables are frequently basted on the surface with butter, lard, or oil to reduce the loss of moisture by evaporation. In recent times, plastic oven bags have become popular for roasts. These cut cooking times and reduce the loss of moisture during roasting, but reduce flavor development from Maillard browning. They are particularly popular for turkeys. Until the late 19th century, roasting by dry heat in an oven was called baking. Roasting originally meant turning meat or a bird on a spit in front of a fire. It is one of the oldest forms of cooking known. Traditionally recognized roasting methods consist only of baking and cooking over or near an open fire. Grilling is normally not technically a roast, since a grill (gridiron) is used (in
English-speaking countries). Smoking differs from roasting because of the lower temperature and controlled smoke application.
Baking is the technique of prolonged cooking of food by dry heat acting by convection, and not by radiation, normally in an oven, but also in hot ashes, or on hot stones. It is primarily used for the preparation of bread, cakes, pastries and pies, tarts, quiches, cookie and crackers. Such items are sometimes referred to as "baked goods," and are sold at a bakery. A person who prepares baked goods as a profession is called a baker. It is also used for the preparation of baked potatoes, baked apples, baked beans, some casseroles and pasta dishes such as lasagna, and various other foods, such as the pretzel. Many commercial ovens are provided with two heating elements: one for baking, using convection and conduction to heat the food, and one for broiling or grilling, heating mainly by radiation. Meat may also be baked, but this is usually reserved for meatloaf, smaller cuts of whole meats, and whole meats that contain stuffing or coating such as breadcrumbs or buttermilk batter; larger cuts prepared without stuffing or coating are more often roasted, a similar process, using higher temperatures and shorter cooking times. Baking can sometimes be combined with grilling to produce a hybrid barbecue variant, by using both methods simultaneously or one before the other, cooking twice. Baking is connected to barbecuing because the concept of the masonry oven is similar to that of a smoke pit. The baking process does not require any fat to be used to cook in an oven. Some makers of snacks such as potato chips or crisps have produced baked versions of their snack items as an alternative to the usual cooking method of deep-frying in an attempt to reduce the calorie or fat content of their snack products.
Grilling is a form of cooking that involves dry heat applied to the surface of food, commonly from above or below. Grilling usually involves quite a lot of direct, radiant heat, and tends to be used for cooking quickly meat that has already been cut into slices (or other pieces). Food to be grilled is cooked on a grill (an open wire grid with a heat source above or below), a grill pan (similar to a frying pan, but with raised ridges to mimic the wires of an open grill), or griddle (a flat plate heated from below). Heat transfer to the food when using a grill is primarily via thermal radiation. Heat transfer when using a grill pan or griddle is by direct conduction. In the United States and Canada, when the heat source for grilling comes from above, grilling is termed broiling. In this case, the pan that holds the food is called a broiler pan, and heat transfer is by thermal radiation. Direct heat grilling can expose food to temperatures often in excess of 260 °C (500 °F). Grilled meat acquires a distinctive roast aroma from a chemical process called the maillard.
The Maillard reaction only occurs when foods reach temperatures in excess of 155 °C (310 °F). Studies have shown that cooking beef, pork, poultry, and fish at high temperatures can lead to the formation of heterocyclic amines, benzopyrenes, and polycyclic aromatic hydrocarbons, which are carcinogens. However, proper marination may reduce the formation of these compounds.
Poaching is the process of gently simmering food in liquid other than oil, generally milk, stock or wine. Poaching is particularly suitable for delicate food, such as eggs, poultry, fish and fruit, which might easily fall apart or dry out. For this reason, it is important to keep the heat low and to keep the poaching time to a bare minimum, which will also preserve the flavor of the food.
Boiling is the rapid vaporization of a liquid, which occurs when a liquid is heated to its boiling point, the temperature at which the vapor pressure of the liquid is equal to the pressure exerted on the liquid by the surrounding environmental pressure. While below the boiling point a liquid evaporates from its surface, at the boiling point vapor bubbles come from the bulk of the liquid. For this to be possible, the vapor pressure must be sufficiently high to win the atmospheric pressure, so that the bubbles can be "inflated". Thus, the difference between evaporation and boiling is "mechanical", rather than thermodynamical. The boiling point is lowered when the pressure of the surrounding atmosphere is reduced, for example by the use of a vacuum pump or at high altitudes. Boiling occurs in three characteristic stages, which are nucleate, transition and film boiling. These stages generally take place from low to high heating surface temperatures, respectively.
Braising is a cooking technique that allows you to slowly cook cuts of meat as well as vegetables in liquid. In its purest form, braising is the equivalent of slow cooker or crock cooking sans the electricity. Although slow cookers are designed to optimize the braising technique. If you are on a budget, this is an excellent cooking technique for you to use. Braising is best used on inexpensive cuts of meat because this mode of cooking helps you to coax tenderness and flavors from the meat that you may not otherwise be able to extract. There are a number of dishes that employ braising to achieve their down-home goodness. Many of these dishes also fall into the category of "comfort food." They include osso buco, pot roast and a host of other stewed, braised and pot-roasted foods that soothe your tummy and warm your soul in the process. The actual braising technique involves wet cooking, and requires that the meat and/or vegetable be seared, then slowly simmered on low heat. Searing is a top-of-the-stove technique; simmering can continue either on top of the stove or in the oven. The process of braising is best accomplished using a heavy stainless, even cast iron, pot which can
adequately accommodate your food of choice. Aside from the obvious budget benefits, braising is also a low-maintenance way to cook great food. The majority of the actual cooking time requires little or no attention from you. The liquids, steam and heat conspire to bring forth a pretty delicious meal while you are off tackling some of the other things on your proverbial plate. In a culture constantly and consistently "pressed for time", braising, then, becomes one of the shining stars in the realm of cooking practices that render gourmet-quality meals without rendering you unproductive.
Commercial microwave ovens all use a timer in their standard operating mode; when the timer runs out, the oven turns itself off. Microwave ovens heat food without getting hot themselves. Taking a pot off a stove, with the exception of an induction cook top, leaves a potentially dangerous heating element or trivet that will stay hot for some time. Likewise, when taking a casserole out of a conventional oven, one's arms are exposed to the very hot walls of the oven. A microwave oven does not pose this problem. Food and cookware taken out of a microwave oven are rarely much hotter than 100 °C (212 °F). Cookware used in a microwave oven is often much cooler than the food because the cookware is transparent to microwaves; the microwaves heat the food directly and the cookware is indirectly heated by the food. Food and cookware from a conventional oven, on the other hand, are the same temperature as the rest of the oven; a typical cooking temperature is 180 °C (356 °F). That means that conventional stoves and ovens can cause more serious burns. The lower temperature of cooking (the boiling point of water) is a significant safety benefit compared to baking in the oven or frying, because it eliminates the formation of tars and char, which are carcinogenic. Microwave radiation also penetrates deeper than direct heat, so that the food is heated by its own internal water content. In contrast, direct heat can fry the surface while the inside is still cold. Pre-heating the food in a microwave oven before putting it into the grill or pan reduces the time needed to heat up the food and reduces the formation of carcinogenic char. Unlike frying and baking, microwaving does not produce acrylamide in potatoes, however unlike deep-frying, it is of only limited effectiveness in reducing glycoalkaloid (i.e. Solanine) levels. Acrylamide has been found in other microwaved products like popcorn
