Seasoning is the process of coating the surface of cookware with fat which is heated in order to produce a corrosion resistant layer of polymerized fat. [1] [2] It is required for raw cast-iron cookware [3] and carbon steel, which otherwise rust rapidly in use, but is also used for many other types of cookware. An advantage of seasoning is that it helps prevent food sticking.
Some cast-iron and carbon steel cookware is pre-seasoned by manufacturers to protect the pan from oxidation (rust), but will need to be further seasoned by the end-users for the cookware to become ready for best nonstick cooking results. [4] To form a strong seasoning, the raw iron item is thoroughly cleaned, coated in a very thin layer of unsaturated fat or oil, and then heated until the bioplastic layer forms, and left to completely cool. Multiple layers are required for the best long-term results.
Stainless steel and aluminium cookware do not require protection from corrosion, but seasoning reduces sticking, and can help with browning as the seasoning coating has high thermal emissivity. [5] [6] Other cookware surfaces are generally not seasoned.
A seasoned surface is hydrophobic and highly attractive to oils and fats used for cooking. These form a layer that prevents foods, which typically contain water, from touching and cooking onto the hydrophilic metallic cooking surface underneath. [7] These properties are useful when frying, roasting and baking.
Food sticks easily to a bare metal cooking surface; it must either be oiled or seasoned before use. [8] The coating known as seasoning is formed by a process of repeatedly layering extremely thin coats of oil on the cookware and oxidizing each layer with medium-high heat for a time. This process is known as "seasoning"; the color of the coating is commonly known as its "patina" - the base coat will darken with use. [9]
To season cookware (e.g., to season a new pan, or to replace damaged seasoning on an old pan), the following is a typical process: First the cookware is thoroughly cleaned to remove old seasoning, manufacturing residues or a possible manufacturer-applied anti corrosion coating and to expose the bare metal. If it is not pre-seasoned, a new cast iron skillet or dutch oven typically comes from the manufacturer with a protective coating of wax or shellac; otherwise it would rust. [10] This needs to be removed before the cookware is used. [11] An initial scouring with hot soapy water will usually remove the protective coating. Alternatively, for woks, it is common to burn off the coating over high heat (outside or under a vent hood) to expose the bare metal surface. For already-used cookware that are to be re-seasoned, the cleaning process can be more complex, involving rust removal and deep cleaning (with strong soap or lye, [12] or by burning in a campfire or self-cleaning oven [13] [ better source needed ]) to remove existing seasoning and build-up.
Then several times the following is performed:
The precise details of the seasoning process differ from one source to another, and there is much disagreement regarding the correct oil to use. There is also no clear consensus about the best temperature and duration. Lodge Manufacturing uses a proprietary soybean blend in their base coats as stated on their website, but states that all oils and fats can be used. [18] The temperature recommended for seasoning varies from high temperatures above 260 °C (500 °F) to temperatures below 150 °C (302 °F).
Seasoning a cast iron or carbon steel wok is a common process in Asia and Asian-American culture. While the vegetable oil method of seasoning is also used in Asia, a traditional process for seasoning also includes the use of Chinese chives or scallions as part of the process. [19]
In conventional seasoning, the oil or fat is converted into a hard surface at or above the high temperatures used for cooking, analogous to the reaction of drying oils. When oils or fats are heated, multiple degradation reactions occur, including decomposition, autoxidation, thermal oxidation, polymerization, and cyclization. [20] [21] [ page range too broad ]
Often cookware's seasoning is uneven, and over time it will spread to the whole item. Heating the cookware (such as in a hot oven or on a stovetop) facilitates the oxidation of the iron; the fats and/or oils protect the metal from contact with the air during the reaction, which would otherwise cause rust to form. Some cast iron users advocate heating the cookware slightly before applying the fat or oil to ensure it is completely dry. [22] [23]
The seasoned surface is hydrophobic and highly attractive to oils and fats used for cooking (oleophilic). These form a layer that prevents foods, which typically contain water, from touching and cooking on to the hydrophilic metallic cooking surface underneath.
The seasoned surface will deteriorate at the temperature where the coating breaks down. This is typically higher than the smoke point of the original oils and fats used to season the cookware. Thus old seasoning can be removed at a sufficiently high temperature (~500 °C), as found in oven self-cleaning cycles.
Some Chinese cookware is seasoned at a much higher temperature than conventional seasoning at 450 °C. More akin to bluing, this type of seasoning mainly involves a chemical change of the iron pan itself and not the oil. When beef tallow is heated at this temperature, it evaporates on the iron surface and increases the partial pressure of O2 (oxygen gas) on the pot surface. This transport of oxygen encourages the formation of Fe3O4 nanoballs. The surface formed is broadly speaking hydrophobic and oleophilic, but is more versatile in that it temporarily turns hydrophilic on contact with high-water ingredients. [24]
Some food writers advise against using seasoned pans and Dutch ovens to cook foods containing tomatoes, vinegar, or other acidic ingredients because these foods would eventually remove the protective layer created during the seasoning process. [25] [26] [27] Tests conducted by America's Test Kitchen found that, while cooking a highly acidic tomato sauce for over 30 minutes produced a metallic taste, cooking acidic food in a well-seasoned pan for a short time is unlikely to have negative consequences. [28] [29] [30] [31] [32]
Cast iron pots are best suited to cook food high in oil or fat, such as chicken, bacon, or sausage, or used for deep frying. Cleaning (except prior to seasoning) is often carried out without the use of detergent. Some cookbook authors recommend only wiping seasoned cookware clean after each use or using other cleaning methods such as a salt scrub or boiling water. [33] The protective layer itself is not very susceptible to soaps, and many users do briefly use detergents and soaps. [28] However, cast iron is very prone to rust, and the protective layer may have pinholes, so soaking for long periods is contraindicated as the layer may start to flake off.
Unlike commercial non-stick coatings such as Teflon, with which metal cooking utensils are not used because they damage the surface, seasoned surfaces tend to be self-reforming, so they allow the use of such utensils. These are of course much more effective in scraping off food than the softer utensils used with non-stick pans. [34] [ page needed ] [32]
In the process of bluing, an oxidizing chemical reaction on an iron surface selectively forms magnetite (Fe3O4), the black oxide of iron (as opposed to rust, the red oxide of iron (Fe2O3)). Black oxide provides some protection against corrosion if also treated with a water-displacing oil to reduce wetting and galvanic action. Bluing is often used with carbon steel and cast iron pans in conjunction with seasoning.
A lubricant is a substance that helps to reduce friction between surfaces in mutual contact, which ultimately reduces the heat generated when the surfaces move. It may also have the function of transmitting forces, transporting foreign particles, or heating or cooling the surfaces. The property of reducing friction is known as lubricity.
A wok is a deep round-bottomed cooking pan of Chinese origin. It is believed to be derived from the South Asian karahi. It is common in Greater China, and similar pans are found in parts of East, South and Southeast Asia, as well as being popular in other parts of the world.
Pan frying or pan-frying is a form of frying food characterized by the use of minimal cooking oil or fat, typically using just enough to lubricate the pan. In the case of a greasy food such as bacon, no oil or fats may need to be added. As a form of frying, the technique relies on oil or fat as the heat transfer medium, and on correct temperature and time to not overcook or burn the food. Pan frying can serve to retain the moisture in foods such as meat and seafood. The food is typically flipped at least once to ensure that both sides are cooked properly.
Grilling is a form of cooking that involves heat applied to the surface of food, commonly from above, below or from the side. Grilling usually involves a significant amount of direct, radiant heat, and tends to be used for cooking meat and vegetables quickly. Food to be grilled is cooked on a grill, using a cast iron/frying pan, or a grill pan.
Cookware and bakeware is food preparation equipment, such as cooking pots, pans, baking sheets etc. used in kitchens. Cookware is used on a stove or range cooktop, while bakeware is used in an oven. Some utensils are considered both cookware and bakeware.
A Dutch oven or casserole dish (international) is a thick-walled cooking pot with a tight-fitting lid. Dutch ovens are usually made of seasoned cast iron; however, some Dutch ovens are instead made of cast aluminum, or ceramic. Some metal varieties are enameled rather than being seasoned, and these are sometimes called French ovens. The international name casserole dish is from the French casserole which means "cooking pot". They are similar to both the Japanese tetsunabe and the sač, a traditional Balkan cast-iron oven, and are related to the South African potjie, the Australian Bedourie oven and Spanish cazuela.
Patina is a thin layer that variously forms on the surface of copper, brass, bronze, and similar metals and metal alloys, or certain stones and wooden furniture, or any similar acquired change of a surface through age and exposure.
Induction cooking is performed using direct electrical induction heating of cooking vessels, rather than relying on indirect radiation, convection, or thermal conduction. Induction cooking allows high power and very rapid increases in temperature to be achieved: changes in heat settings are instantaneous.
Cooking spray is a spray form of an oil as a lubricant, lecithin as an emulsifier, and a propellant such as nitrous oxide, carbon dioxide or propane. Cooking spray is applied to frying pans and other cookware to prevent food from sticking. Traditionally, cooks use butter, shortening, or oils poured or rubbed on cookware. Most cooking sprays have less food energy per serving than an application of vegetable oil, because they are applied in a much thinner layer: US regulations allow many to be labelled "zero-calorie"; in the UK sprays claim to supply "less than 1 calorie per serving". Popular US brands include Pam, Crisco, and Baker's Joy. Sprays are available with plain vegetable oil, butter and olive oil flavor.
Bluing, sometimes spelled as blueing, is a passivation process in which steel is partially protected against rust using a black oxide coating. It is named after the blue-black appearance of the resulting protective finish. Bluing involves an electrochemical conversion coating resulting from an oxidizing chemical reaction with iron on the surface selectively forming magnetite, the black oxide of iron. In comparison, rust, the red oxide of iron, undergoes an extremely large volume change upon hydration; as a result, the oxide easily flakes off, causing the typical reddish rusting away of iron. Black oxide provides minimal protection against corrosion, unless also treated with a water-displacing oil to reduce wetting and galvanic action. In colloquial use, thin coatings of black oxide are often termed 'gun bluing', while heavier coatings are termed 'black oxide'. Both refer to the same chemical process for providing true gun bluing.
The following outline is provided as an overview of and topical guide to the preparation of food:
Heavy-duty cookware made of cast iron is valued for its heat retention, durability, ability to maintain high temperatures for longer time duration, and non-stick cooking when properly seasoned. Seasoning is also used to protect bare cast iron from rust. Types of cast iron cookware include frying pans, dutch ovens, griddles, waffle irons, flattop grills, panini presses, crepe makers, deep fryers, tetsubin, woks, potjies, and karahi.
A non-stick surface is engineered to reduce the ability of other materials to stick to it. Non-stick cookware is a common application, where the non-stick coating allows food to brown without sticking to the pan. Non-stick is often used to refer to surfaces coated with polytetrafluoroethylene (PTFE), a well-known brand of which is Teflon. In the twenty-first century, other coatings have been marketed as non-stick, such as anodized aluminium, silica, enameled cast iron, and seasoned cookware.
Cousances was a brand of enameled cast iron cookware. originally manufactured by a foundry in the town of Cousances-les-Forges in northeastern France. The Cousances foundry began making cast iron pans in 1553. Four centuries later, in 1957, the brand was acquired by Le Creuset. Cookware under the Cousances brand continued to be manufactured by Le Creuset into the early 1980s.
A frying pan, frypan, or skillet is a flat-bottomed pan used for frying, searing, and browning foods. It is typically 20 to 30 cm in diameter with relatively low sides that flare outwards, a long handle, and no lid. Larger pans may have a small grab handle opposite the main handle. A pan of similar dimensions, but with less flared, more vertical sides and often with a lid, is called a sauté pan. While a sauté pan can be used as a frying pan, it is designed for lower heat cooking.
A roasting pan is a piece of cookware used for roasting meat in an oven, either with or without vegetables or other ingredients. A roasting pan may be used with a rack that sits inside the pan and lets the meat sit above the fat and juice drippings.
In cooking several factors, including materials, techniques, and temperature, can influence the surface chemistry of the chemical reactions and interactions that create food. All of these factors depend on the chemical properties of the surfaces of the materials used. The material properties of cookware, such as hydrophobicity, surface roughness, and conductivity can impact the taste of a dish dramatically. The technique of food preparation alters food in fundamentally different ways, which produce unique textures and flavors. The temperature of food preparation must be considered when choosing the correct ingredients.