Sciencey Facts You Should Know
There are three general types of cooking methods: dry-heat, moist-heat, and combination cooking. Each method can be used to bring out the flavor and tenderness of specific dishes and are associated with specific regional cuisines – a good example might be WOK cooking, a dry heat method linked to many Asian cuisines. To be a competent cook, you need to be able to use each of these cooking methods well (or at least understand how a decent chef might use them).
Heat Transfer
Cooking is simply the transfer of heat from a source to food.
Heat is a type of energy. When two things of different temperatures come in contact, energy, in the form of heat, transfers from the warmer item to the cooler until they both reach equilibrium – the same temperature. Heat travels to items in only three ways: conduction, convection, or radiation.
Conduction is the transfer of heat from one item to another when the items come into direct contact with each other. When you stick a metal spoon into a pot of boiling water, heat travels up the spoon and eventually makes the whole spoon hot. The water in the pot is being heated by conduction – the element under the pot heats the metal and that heat energy is transferred to the pot.
Sometimes the heat of cooked food is transferred to the air (like when your food gets cold waiting for you to eat it!) Sometimes heat migrates from surface to surface, like when a cold salad gets warm after being put on a warm plate. The heat of the plate is conducted to the salad.
Convection is the transfer of heat caused by the movement of molecules (in the air, water, or fat) from a warmer area to a cooler one. When heating water, natural convection occurs. As water heats at the bottom of the pot, it becomes less dense and travels upward. In the process, it transfers energy to the cooler water higher in the pot. This is a continuous process, with the hot water constantly rising and replacing the cooling water.
Mechanical convection occurs in ovens equipped with fans that rapidly move hot air around inside the cooking area, baking or roasting items more quickly than they would cook in a regular oven.
Radiation was the first method of cooking, ever. Put some food near a fire and infrared waves of energy move outwards in all directions, heating the food. If you’ve ever warmed your hands beside a fire, you’ve experienced this method of heat transfer. (Note: if you put your hands OVER the fire, you also experienced convection – the upwards movement of heat). Toast a marshmallow OVER a fire using convection cooking, and it will turn black pretty quick. Toast a marshmallow off to the side and NEAR a fire? That’s radiation cooking and it will toast much more slowly, won’t burn, and you’ll get a delicious s’mores. Nice.
Pizza ovens are all based on radiation heat transfer – you snuggle the pizza up close to the flames and let the infrared waves do the work
Remember
Radiation is the only form of heat transfer that does not require any kind of physical contact between the heat source and the food being cooked.
When grilling foods, you’ve got all three heat transfer methods at work at the same time: heat is being transferred straight UP through hot air (convection), the fire heats the grate (conduction), and the infrared waves produced by the fire itself affect the exterior of food (radiation). The result is that the outside of the food browns.
Microwaves work by radiation too, but that type of infrared wave works from the INSIDE OUT, agitating the water molecules in food, creating a form of friction that heats the water and thereby the food. Microwaves penetrate the item, so browning does not take place. Microwaving is good for some recipes, but most food items can quickly become tough and rubbery or dried out if microwaved too long. So don’t cook foods in the microwave.
As Gordon Ramsay would say, that’s embarrassing.
DRY-HEAT COOKING METHODS
In dry-heat cooking, food is cooked either by direct heat, like on a grill, or by indirect heat in a closed environment, like in an oven. Dry-heat cooking methods without fat include the following:
- Broiling
- Grilling
- Roasting
- Baking
Another way to prepare food is to use dry-heat cooking methods with fat and oil. These methods include the following:
- Sauteing
- Pan-frying
- Stir-frying
- Deep-frying
“Searing” is not listed on the technique below, though it is certainly a cooking technique.
Searing is a unique cooking method that involves heating a surface to a very high temperature (sometimes hotter than 800 degrees) and placing the food on the surface until a crust forms. This gives steaks the meaty “bite” people adore, all while locking in moisture.
Searing is usually best for meats, seafood, and certain types of vegetables. Filet mignon, anyone?
Broiling
Broiling is a rapid cooking method that uses high heat from a source located above the food. Broiled food becomes browned on the top. Food items that can be broiled include tender cuts of meat, young poultry, fish, and some fruits and vegetables.
Broiling is often seen as the “sibling” to roasting. Unlike roasting, where the heat comes from below the food to be cooked, broiling has its heat source above the heat source. It also happens to have a much higher temperature, one that usually starts at 400 degrees. This allows the food to get crispy on the outside while keeping it all juicy on the inside.
Grilling
Grilling is a very simple dry-heat method that is excellent for cooking smaller pieces of food. The food is cooked on a grill rack above the heat source. No liquid is added to the food during cooking. A cook might add small amounts of fat or oil during the cooking process simply to add flavor to the finished dish.
The result of grilling is food with a highly flavored outside and a moist inside. Grilled food has a smoky, slightly charred flavor because the fat melts and drips down into the heat source, along with some of the meat’s juices. As the fat and juices burn, the smoke helps provide the charred flavor. The crosshatching look common to grilled food comes from the hot metal grill rack that the food sits on. Special woods, such as mesquite, hickory, or apple, can be used in the heat source to flavor the grilled food. Using a marinade can give the food a unique flavor, as well as making it more moist.
Roasting
Roasting and baking are techniques that cook food by surrounding the items with hot, dry air in the oven. As the outer layers of the food become heated, the food’s natural juices turn to steam and are absorbed into the food. These juices create a natural sauce. Food items that can be baked or roasted include fish, tender meats and poultry, and some fruits and vegetables. You can bake food covered or uncovered, depending on the recipe. Food items that are baked uncovered, such as cookies and casseroles, develop a golden-brown color on top.
Roasting generally requires longer cooking times and often for the food to be raised off the pan by a rack or a bed of mirepoix. Roasting is most often used with large cuts of meat, whole birds (poultry), or fish. Adding liquid to the pan and/or basting during the roasting process will add flavor, moisture, and color to the food. Roasted food should have a golden-brown exterior and moist, tender interior.
Griddling
Griddling is cooking a food item on a hot, flat surface (known as a griddle) or in a relatively dry, heavy-bottomed fry pan or cast-iron skillet. The goal is to give the product an even, golden-brown finish and a slightly crisp exterior texture. When cooking meats on a high-heat griddle or in a cast-iron pan, the result is a high level of browning that gives the finished product a unique taste and texture not achieved with other cooking methods. In particular, steaks, chops, and chicken breasts are often cooked on a griddle or in a hot cast-iron skillet.
The griddle is also used to prepare one of the most popular breakfast menu items-griddle cakes (pancakes). To produce a quality product, clean the griddle well and make sure the temperature of the griddle surface is appropriate for the item being cooked.
Sauteing
The sauteing (saw-TAY-ing) method cooks food rapidly in a small amount of fat over relatively high heat. The fat adds to the flavor. Select cuts of meat, chicken, and fish or seafood are often prepared this way. The thinner and more delicate the piece of meat, the faster it will cook. The literal translation of the French term saute is “jump.” To saute is to cook the food quickly to keep water and vitamin loss at a minimum, while gaining a high degree of color and flavor. When sauteing, the pan is heated first, and just enough fat is added to coat the bottom of the pan.
Stir-Frying
Stir-frying is a cooking method closely related to sauteing. Like sauteing, it is a quick-cooking, dry-heat method. Food is cooked over a very high heat, generally in a wok with little fat, and stirred quickly. In this Asian style of cooking, sauce is usually created in the same pan after the product has been sauteed. The items to be stir-fried, usually meats and fresh vegetables, are cut into bite-sized pieces. Figure 18.6 is an example of stir-fry cooking. The wok, a bowl-shaped pan, makes stir-frying easy. A wok is usually made of rolled steel and is used for nearly all Chinese cooking methods.
Pan-Frying
Cooking techniques that use more fat than those discussed so far include panfrying and deep-frying. To pan-fry food, cook it in oil over less intense heat than that used for sauteing or stir-frying. Many recipes call for coating the food with batter, seasoned flour, or breading first. The hot oil seals the food’s coated surface and locks the natural juices inside, instead of releasing them. The oil should be deep enough to come halfway up the side of the food being cooked.
The object of pan-frying is to produce a flavorful exterior with a crisp, brown crust that helps retain the food’s juices and flavor. Food to be pan-fried, such as beef tenderloin cuts or fish fillets, is not cut into small pieces before cooking. So, pan-frying requires a lower heat so that the exterior of the food does not overcook while the interior reaches the proper temperature. Even after cooking, the food should be tender and moist. Pan-fried food may be held for only a short time before being served. The outside of the food should be evenly golden brown, with a firm crust.
Deep Frying
Technically, deep-frying is considered a dry-heat cooking method with fat. However, there are so many special rules about deep frying and terms to lear, most chefs consider deep frying a cooking method ALMOST in its own category.
To deep-fry food, bread or batter-coat it, immerse (completely cover) it in hot fat, and fry it until it is done. The outside of the food item develops a crispy coating, while the inside stays moist and tender. The coating on the food can be a standard breading or a batter.
A batter combines dry and wet ingredients. It is a mixture of the primary dry ingredient (wheat flour, all-purpose flour, cornmeal, or rice flour), the liquid (beer, milk, wine, or water), and a binder (generally egg), which helps the mixture adhere to the product.
Examples include the beer batter often used on fish, cornmeal batter used on corn dogs, and tempura batter (light batter) used on tempura vegetables and fish.
A breading has the same components as batter, but they are not blended together. A standard breading would be seasoned all-purpose flour wwith an egg and milk dip.
Food that can be deep-fried must be naturally tender and of a shape and size that allows it to cook quickly without becoming tough or dry. As much as 35 percent of the flavor of a deep-fried food comes from the oil in which it is fried. Always use a good-quality oil.
The float of the item – the point when the item rises to the surface of the oil and appears golden brown – indicates doneness. To ensure doneness, check a piece of the item being cooked for the proper internal temperature. The crust should be crisp and delicate, surrounding a moist, tender piece of meat, fish, poultry, or vegetable.
There are three methods for deep-frying food:
- In the swimming method, gently drop breaded or batter-coated food in hot oil, where it falls to the bottom of the fryer and then swims to the surface. Once the food items reach the surface, turn them over, if necessary, so they brown on both sides.
- In the basket method, bread the food, place it in a basket, lower the basket and food into the hot oil, and then lift it all out with the basket when the food is done.
- Use the double-basket method for certain foods that need to be fully submerged in hot oil for a longer period of time in order to develop a crisp crust. In this method, place the food item in a basket, and then fit another basket on top of the first. The top basket keeps the food from floating to the surface of the oil.
Recovery time is the amount of time it takes oil to reheat to the correct cooking temperature once food is added. The more food items dropped into the oil at one time, the longer the recovery time.
The smoke point is the temperature at which fats and oils begin to smoke, which means that the fat has begun to break down. Use oil for deep-frying that has a neutral flavor and color and a high smoking point, around 425°F.
How to Add Moisture to Dry-Heat Cooking
Some food will lose moisture and become dry when cooked using dry heat. Any food prepared using dry heat must be naturally tender or prepared by adding moisture. There are several ways to add moisture. Here are a few:
- Barding: Wrapping an item (usually a naturally lean piece of meat, such as pork tenderloin) with strips of fat before cooking to baste the meat, making it moister.
- Larding: Inserting long, thin strips of fat into a large, naturally lean piece of meal with a special needle before cooking to baste the meal from the inside.
- Marinating: Soaking an item in a combination of wet and dry ingredients to provide flavor and moisture.
- Brining: Soaking an item in a high salinity liquid to increase the items ability to retain moisture while cooking
MOIST-HEAT COOKING METHODS
Moist-heat cooking techniques produce food that is delicately flavored and moist, sometimes with a rich broth that can be served as a separate course or used as a sauce base. In fact, an entire dinner, complete with meat, fish, or poultry and vegetables, can be cooked in one pot. One example of this is the classic New England boiled dinner, consisting of corned beef, cabbage, carrots, and potatoes. Moist-heat cooking methods provide the opportunity to create nutritious, appealing dishes with a range of flavors and textures.
Moist-heat cooking methods include the following:
- Simmering
- Blanching
- Poaching and shallow poaching
- Steaming
While “boiling” isn’t a category listed here, of course, on occasion, you are called on to boil foods. Rarely. A rolling boil means the water is vigorously bubbling. All boiling water is 212*F and will easily dry out most foods and the current of the boiling water can even damaged delicate ingredients. Boil food with caution.
Simmering
When simmering, you completely submerge food in a liquid that is at a constant, moderate temperature. Use well-flavored liquid and cuts of meat that are less tender than those recommended for dry-heat cooking methods. Simmering less-tender items cooks them at a slightly higher temperature than other moist-heat methods, 185°F to 205°F (85°C to 96°C). Simmering differs from boiling in that bubbles in a simmering liquid rise gently and just begin to break the surface. Do not allow the water to come to a full boil, because the boiling motion will cause meat to become stringy and rubbery.
Poaching
When poaching, cook food between 160°F and 180°F (71 °C and 82°C). The surface of the poaching liquid should show some motion, but no air bubbles should break the surface. Use well-flavored liquid, and make sure the food is naturally tender. Cooks commonly poach chicken and seafood. Cooks also often serve poached and simmered items with a flavorful sauce prepared from the poaching/simmering liquid to add zest to the dish’s mild flavor. Be careful not to overcook poached and simmered food.
Blanching
Blanching is a variation of boiling. When blanching, you are partially cooking the food (this is also called parcooking), and then finishing it later. Cooks frequently use blanching to pre-prepare vegetables.
Blanching is a two-step process. Take green beans as an example. Once you know the green beans are cooked, quickly remove them from the boiling water and plunge them into the ice bath to halt the cooking process. This technique is called shocking. Then give them a quick toss with seasoned butter in a hot pan at service. The result is a green bean cooked to perfection, with bright color, but prepared fresh and quickly at service. Many times, cooks blanch food that would otherwise take too long to cook thoroughly, before they deep-fry it.
Steaming
Steaming is cooking food by surrounding it in steam in a confined space such as a steamer basket, steam cabinet, or combi-oven. Direct contact with the steam cooks the food. Care should be taken when removing items from a steamer, to avoid burns.
Steaming can take place with or without pressure. Placing food in a steamer basket on top of a pot of boiling water directly exposes the food to steam, which is 212°F. Placing food in a commercial steam cabinet or combi-oven also cooks food through direct contact with the steam, but the temperature is generally higher because the steam is under pressure. It cannot escape the cabinet or oven. Both methods cook in the same way, but steaming with pressure cooks faster than steaming without pressure. Take this into consideration when preparing a dish.
Enhance the flavor of food steamed over, but not directly in, boiling liquid by using broth instead of water as the liquid. Use naturally tender food, cut it into small pieces, and place it on a rack above the boiling liquid within a closed cooking pot. As the liquid comes to a boil, the steam created surrounds the food, heating it evenly and keeping it moist. Once all the ingredients are in the steamer and the cover is in place, do not remove the lid because the steam will escape, slowing down the cooking process.
When you cook with steam, food keeps more of its nutritional value and there are no added calories from fat or oil. Items cooked with steam have mild, delicate flavors and often have a fresher taste, color, and appearance. Cooking time is longer with steaming than with boiling or simmering. But you have to be careful that food is not overcooked. Steamed food should be moist and plump, not rubbery or chewy.
There is a fifth type of moist heat cooking that is fairly specialized: Shallow Poaching.
Shallow poaching cooks food using a combination of steam and a liquid bath. Shallow poaching is a last-minute cooking method most suitable for food that is cut into portion-sized or smaller pieces.
When shallow poaching, the food is partially covered by a liquid containing an acid (usually wine or lemon juice), herbs, and spices in a covered pan. The steam cooks the items that are not directly covered by the poaching liquid. Food that has been shallow poached should be very tender and moist, with a fragile texture.
Cooks commonly shallow poach paupiettes of sole and other white fishes.
Paupiettes are long, thin slices of fish or meat that are rolled and stuffed with a filling. Shallow poaching transfers much of the flavor of the food from the food item to the liquid. To keep this lost flavor, use the poaching liquid as a sauce base. This liquid is called a cuisson.
COMBINATION-COOKING METHODS
Sometimes the best method for preparing a certain food is a combination of both dry-heat and moist-heat cooking methods. Such cooking is called combination cooking. For example, braising and stewing use both dry and moist heat to cook food that is less tender. Combination-cooking techniques are useful because they can transform the less tender and less expensive main ingredients into delicious and tender finished products.
Combination-cooking methods include the following:
- Braising: Primarily used for larger cuts of meat
- Stewing: Used for smaller pieces of food
Braising
In braising, first sear the food item in hot oil, and then partially cover it in enough liquid to come halfway up the food item. Then cover the pot or pan tightly, and finish the food slowly in the oven or on the stove top until it is tender. A bed of seasonings adds moisture and flavor to the food. If the recipe calls for them, add vegetables to braised meat or poultry near the end of the cooking time. As the meat cooks, its flavor is released into the cooking liquid, which becomes the accompanying sauce. The key to quality braising is long, slow cooking. In an item such as coq au vin (chicken cooked in red wine ), the meat should slide from the bone in the final product, and the meat itself should fall apart with a gentle touch.
Slow, gentle braising causes the tougher connective tissue of lean meat to become fork tender and well done. More tender food requires less cooking fluid and can be heated at lower temperatures for a shorter time. Few nutrients are lost with braising. Braised food that is finished in the oven is less likely to be scorched than food that is finished on the stove top. Braised food should be extremely tender, but should not fall into shreds.
An example of a braising technique is pot roasting, which is a common American term for braising, and the name of a traditional dish (pot roast).
Stewing
Stewing techniques are similar to braising, but the pre-preparation is a little different. First, you cut the main food item into bite-sized pieces and either blanch or sear them. As with braising, you cook the food in oil first, and then add liquid. Stewing requires more liquid than braising. Cover the food completely while it is simmering.
OTHER COOKING METHODS: Sous Vide and Microwaves
Two other cooking methods are sous vide and microwave cooking. Sous vide involves sealing the food in sturdy plastic bags to keep in the juices and aroma that otherwise would be lost in the process. Microwave cooking involves heating food by passing microwave radiation through it.
Sous Vide Cooking
Sous vide is a method in which food is cooked for a long time, sometimes well over 24 hours. Sous vide is French for “under vacuum.” Rather than placing food in a slow cooker, the sous vide method places food in airtight plastic bags in water that is hot but WELL below boiling. This cooks the food using precisely controlled heating, at the temperature at which it should be served. The water might feel about as hot as a hot bath in a bathtub.
For safety and quality reasons, sous vide water-bath temperatures are measured INCREDIBLY carefully – in tenths of a degree. The exact range is narrow and precise.
During regular cooking, the FACT that you can smell it actually means that precious molecules of flavor are escaping from the food. Sous vide locks all of those flavor molecules in with the vacuum seal. Sous vide food items do not lose flavor. In fact, in most cases, the flavors actually intensify and improve.
Microwave Cooking
Many food items can be baked or roasted in a microwave oven. However, microwave ovens do not give the same results as convection or conventional ovens because they cook food with waves of energy or radiation, rather than with heat.
Microwave cooking alters protein, causing it to toughen. This can be a problem in breads, eggs, and meats. Cooks can use special techniques with specific microwave recipes to maintain the quality of the finished recipe. Because there is no external heat source, there is no browning. Food cooks because microwave radiation increases molecular activity inside the food. It begins at the center, so the surface does not turn a crispy golden brown while the inside slowly cooks, as in a conventional oven. Glass and ceramic cookware and plastics that are labeled microwave safe can be used in the microwave oven. Never use brown grocery bags, newspaper, metal, or foil in the microwave oven.
Slow Cooking, a.k.a, the Crockpot
People who own a Crock-Pot already know what this is: the ultimate cooking method for people who want a “set it and forget” type of cooking method. One of the best ways to make chili is putting your ingredients in a slow cooker, using low temperatures over long periods of time. The result is food that is tender and tastes delicious.
Pressure Cooker
Increase the pressure, reduce the amount of time something cooks. Want to make stock in two hours instead of 6? You need a pressure cooker. The high atmospheric pressure created by heating water without letting the steam escape limits boiling and permits getting the temperature of the interior much higher than normal.
DETERMINING DONENESS
There are two important qualities that are used to determine a product’s doneness:
- Has it achieved the desired texture?
- Has it reached the minimum internal temperature it needs to be safe?
For products that are made in large quantities, many restaurant and foodservice operations will test the products to determine the standardized cooking temperature and the length of cooking time that will produce the same doneness every time. This type of control depends on cooking the same size or quantity of product every time.
It is important to check the temperature of the item both in the tests that lead to standardized cooking times and temperatures and in the determination of doneness in smaller quantities and individual items, such as a steak or chicken breast. Never assume that an item is at the right temperature because it has finished its standardized cooking time.
In addition, carryover cooking needs to be taken into consideration when gauging cooking times. Carryover cooking refers to the process of continued cooking after a food item has been removed from its heat source.