Editing Cookware and bakeware (section)

===Metal===
Metal pots are made from a narrow range of metals because pots and [[Frying pan|pan]]s need to [[Heat conduction|conduct]] heat well, but also need to be [[chemically unreactive]] so that they do not alter the flavor of the food.<ref>{{Cite web |title=What's the Difference Between Nonreactive and Reactive Pans? |url=https://www.thekitchn.com/whats-the-deal-with-reactive-a-108699 |access-date=2023-06-06 |website=Kitchn |language=en}}</ref> Most materials that are conductive enough to heat evenly are too reactive to use in food preparation. In some cases (copper pots, for example), a pot may be made out of a more reactive metal, and then [[tinning|tinned]] or clad with another. While metal pots take heat very well, they usually react poorly to rapid cooling, such as being plunged into water while hot, this will usually warp the piece over time.

====Aluminium====
<!-- For discussions about spelling refer to talk pages. British spelling without appropriate discussions and justifications -->
[[File:Circulon-anodized-aluminum.jpg|thumb|right|An anodized aluminium [[#Sauté pan|sauté pan]]]]

Aluminium is a lightweight metal with very good thermal conductivity. It is resistant to many forms of corrosion.  Aluminium is commonly available in sheet, cast, or anodized forms,{{sfn|Williams|1986|pp=8–9}} and may be physically combined with other metals (see below).

Sheet aluminium is spun or stamped into form. Due to the softness of the metal, it may be alloyed with magnesium, copper, or bronze to increase its strength. Sheet aluminium is commonly used for baking sheets, pie plates, and cake or muffin pans.  Deep or shallow pots may be formed from sheet aluminium.

Cast aluminium can produce a thicker product than sheet aluminium, and is appropriate for irregular shapes and thicknesses.  Due to the microscopic pores caused by the casting process, cast aluminium has a lower thermal conductivity than sheet aluminium.  It is also more expensive.  Accordingly, cast aluminium cookware has become less common.  It is used, for example, to make [[Dutch oven]]s lightweight and [[bundt]] pans heavy duty, and used in ladles and handles and [[wok]]s to keep the sides at a lower temperature than the center.

[[Anodized aluminium]] has had the naturally occurring layer of [[aluminium oxide]] thickened by [[anodizing#Process|an electrolytic process]] to create a surface that is hard and non-reactive. It is used for sauté pans, stockpots, roasters, and Dutch ovens.{{sfn|Williams|1986|pp=8–9}}

Uncoated and un-anodized aluminium can react with acidic foods to change the taste of the food. Sauces containing egg yolks, or vegetables such as asparagus or artichokes may cause oxidation of non-anodized aluminium.

Aluminium exposure has been suggested as a risk factor for [[Alzheimer's disease]].<ref>
{{cite web | title=Am I at risk of developing dementia? | publisher=Alzheimer's Society | work=Facts about dementia | url=http://www.alzheimers.org.uk/Facts_about_dementia/Risk_factors/info_aluminium.htm | access-date=October 14, 2005 | archive-url=https://web.archive.org/web/20150523043238/http://www.alzheimers.org.uk/site/scripts/documents_info.php?documentID=102 | archive-date=23 May 2015 | url-status=dead }}
</ref><ref>{{cite journal|last1=Bondy|first1=SC|title=Low levels of aluminum can lead to behavioral and morphological changes associated with Alzheimer's disease and age-related neurodegeneration.|journal=Neurotoxicology|date=January 2016|volume=52|pages=222–9|pmid=26687397|doi=10.1016/j.neuro.2015.12.002|s2cid=261385155 |url=https://escholarship.org/uc/item/5c15r7xj}}</ref>{{too many pages|date=October 2021}}<ref>{{cite journal|last1=Kandimalla|first1=R|last2=Vallamkondu|first2=J|last3=Corgiat|first3=EB|last4=Gill|first4=KD|title=Understanding Aspects of Aluminum Exposure in Alzheimer's Disease Development.|journal=Brain Pathology (Zurich, Switzerland)|date=March 2016|volume=26|issue=2|pages=139–54|pmid=26494454|doi=10.1111/bpa.12333|pmc=8028870}}</ref>{{too many pages|date=October 2021}} Of one of which its proponents is  Prof. [[Christopher Exley]], who has published his findings. However, the Alzheimer's Association states that "studies have failed to confirm any role for aluminum in causing Alzheimer's."<ref>{{cite web 
| url=http://www.alz.org/alzheimers_disease_myths_about_alzheimers.asp
| title=Myth 4: Drinking out of aluminum cans or cooking in aluminum pots and pans can lead to Alzheimer's disease
| publisher=Alzheimer's Association
| work=Alzheimer Myths 
| access-date=June 19, 2010
}}</ref>{{better source|date=October 2021}} The link remains controversial.<ref>{{cite journal|last1=Yegambaram|first1=M|last2=Manivannan|first2=B|last3=Beach|first3=TG|last4=Halden|first4=RU|title=Role of environmental contaminants in the etiology of Alzheimer's disease: a review.|journal=Current Alzheimer Research|date=2015|volume=12|issue=2|pages=116–46|pmid=25654508|doi=10.2174/1567205012666150204121719|pmc=4428475}}</ref>{{too many pages|date=October 2021}}

[[File:Casseroles cuivre Vaux.jpg|thumb|Copper saucepans, [[Vaux-le-Vicomte]] castle]]

====Copper====
[[Copper]] provides the highest thermal conductivity among non-[[noble metal]]s and is therefore fast [[heat]]ing with unparalleled heat distribution ''(see: [[Copper in heat exchangers]]).'' Pots and pans are [[cold forming|cold-formed]] from copper sheets of various thicknesses, with those in excess of 2.5&nbsp;mm considered commercial (or ''extra-fort'') grade. Between 1&nbsp;mm and 2.5&nbsp;mm wall thickness is considered utility (''fort'') grade, with thicknesses below 1.5&nbsp;mm often requiring [[tube beading]] or [[edge rolling]] for reinforcement. Less than 1mm wall thickness is generally considered decorative, with exception made for the case of .75–1&nbsp;mm [[planishing|planished]] copper, which is [[work hardening|hardened]] by hammering and therefore expresses performance and strength characteristic of thicker material.

Copper thickness of less than .25&nbsp;mm is, in the case of cookware, referred to as [[foil (metal)|foil]] and must be formed to a more structurally rigid metal to produce a serviceable vessel. Such applications of copper are purely aesthetic and do not materially contribute to cookware performance.

Copper is reactive with acidic foods which can result in corrosion, the byproducts of which can foment [[copper toxicity]]. In certain circumstances, however, unlined copper is recommended and safe, for instance in the preparation of [[meringue]], where copper ions prompt proteins to denature (unfold) and enable stronger protein bonds across the sulfur contained in egg whites. Unlined copper is also used in the making of preserves, jams and jellies. Copper does not store ("bank") heat, and so thermal flows reverse almost immediately upon removal from heat. This allows precise control of consistency and texture while cooking sugar and pectin-thickened preparations. Alone, fruit acid would be sufficient to cause leaching of copper byproducts, but naturally occurring fruit sugars and added preserving sugars buffer copper reactivity. Unlined pans have thereby been used safely in such applications for centuries.

Lining copper pots and pans prevents copper from contact with [[acid]]ic foods. The most popular lining types are [[tin]], [[stainless steel]], [[nickel]] and [[silver]].

The use of tin dates back many centuries and is the original lining for copper cookware. Although the patent for [[canning]] in sheet tin was secured in 1810 in England, legendary French chef [[Auguste Escoffier]] experimented with a solution for provisioning the French army while in the field by adapting the tin lining techniques used for his cookware to more robust steel containers (then only lately introduced for canning) which protected the cans from corrosion and soldiers from lead solder and [[botulism]] poisoning.

Tin linings sufficiently robust for cooking are wiped onto copper by hand, producing a .35–45-mm-thick lining.{{sfn|Hoare|1959|p=82}} Decorative copper cookware, i.e., a pot or pan less than 1&nbsp;mm thick and therefore unsuited to cooking, will often be [[electroplating|electroplate]] lined with tin. Should a wiped tin lining be damaged or wear out the cookware can be re-tinned, usually for much less cost than the purchase price of the pan. Tin presents a smooth crystalline structure and is therefore relatively non-stick in cooking applications. As a relatively soft metal abrasive cleansers or cleaning techniques can accelerate wear of tin linings. Wood, silicone or plastic implements are to preferred over harder stainless steel types.

For a period following the Second World War, copper cookware was [[electroplating|electroplated]] with a nickel lining. Nickel is harder and more thermally efficient than tin, with a higher melting point. Despite its hardness, it wore out as fast as tin, as the plating was 20 microns thick or less, as nickel tends to plate somewhat irregularly, and requires milling to produce an even cooking surface. Nickel is also stickier than tin or silver. Copper cookware with aged or damaged nickel linings can be retinned, or possibly replating with nickel, although this is no longer widely available. Nickel linings began to fall out of favor in the 1980s owing to the isolation of nickel as an allergen.

Silver is also applied to copper by means of electroplating, and provides an interior finish that is at once smooth, more durable than either tin or nickel, relatively non-stick and extremely thermally efficient. Copper and silver bond extremely well owing to their shared high [[Electrical resistivity and conductivity|electro-conductivity]]. Lining thickness varies widely by maker, but averages between 7 and 10 microns. The disadvantages of silver are expense and the tendency of sulfurous foods, especially [[Brassica oleracea|brassicas]], to discolor. Worn silver linings on copper cookware can be restored by stripping and re-electroplating.

Copper cookware lined with a thin layer of stainless steel is available from most modern European manufacturers. Stainless steel is 25 times less thermally conductive than copper, and is sometimes critiqued for compromising the efficacy of the copper with which it is bonded. Among the advantages of stainless steel are its durability and corrosion resistance, and although relatively sticky and subject to food residue adhesions, stainless steel is tolerant of most abrasive cleaning techniques and metal implements. Stainless steel forms a pan's structural element when bonded to copper and is irreparable in the event of wear or damage.

Using modern metal [[Thermocompression bonding|bonding]] techniques, such as [[Cladding (metalworking)|cladding]], copper is frequently incorporated into cookware constructed of primarily dissimilar metal, such as stainless steel, often as an enclosed diffusion layer (see ''coated and composite cookware'' below).

====Cast iron====
[[File:Pfanne (Gusseisen).jpg|thumb|right|[[Cast-iron]]]]

{{Main|Cast-iron cookware}}
Cast-iron cookware is slow to heat, but once at temperature provides even heating.<ref>{{Cite news |last=Wolke |first=Robert L. |date=April 4, 2001 |title=Cast-Iron Clinic |url=https://www.washingtonpost.com/archive/lifestyle/food/2001/04/04/cast-iron-clinic/247e7db7-375b-49f8-8c69-9485cf9f4418/ |newspaper=The Washington Post}}</ref> Cast iron can also withstand very high temperatures, making cast iron pans ideal for [[searing]]. Being a reactive material, cast iron can have [[chemical reaction]]s with high acid foods such as [[wine]] or [[tomato]]es. In addition, some foods (such as [[spinach]]) cooked on bare cast iron will turn black.

[[Cast iron]] is a somewhat brittle, porous material that rusts easily. As a result, it should not be dropped or heated unevenly and it typically requires [[Seasoning (cookware)|seasoning]] before use. Seasoning creates a thin layer of oxidized [[fat]] over the iron that coats and protects the surface from corrosion, and prevents sticking.<ref>{{Cite web |author1=Megan Slack |date=2022-06-14 |title=How to maintain an iron cast pan – 5 ways experts always favor |url=https://www.homesandgardens.com/kitchens/how-to-maintain-an-iron-cast-pan |access-date=2022-06-26 |website=homesandgardens.com |language=en}}</ref>

Enameled cast-iron cookware was developed in the 1920s. In 1934, the French company [[Cousances]] designed the enameled cast iron Doufeu to reduce excessive evaporation and scorching in cast iron Dutch ovens.  Modeled on old braising pans in which glowing charcoal was heaped on the lids (to mimic two-fire ovens), the Doufeu has a deep recess in its lid which instead is filled with ice cubes.  This keeps the lid at a lower temperature than the pot bottom.  Further, little notches on the inside of the lid allow the moisture to collect and drop back into the food during the cooking.  Although the Doufeu (literally, "gentlefire") can be used in an oven (without the ice, as a casserole pan), it is chiefly designed for stove top use. Enameled cast-iron cookware, unlike uncoated cast-iron, is minimally reactive thus can be used with acidic food.<ref>{{Cite news |last=Krystal |first=Becky |date=April 26, 2021 |title=Regular vs. enameled cast iron: How they compare for cooking and cleaning |url=https://www.washingtonpost.com/food/2021/04/26/cast-iron-enameled-seasoning-care/ |newspaper=The Washington Post}}</ref>

====Stainless steel====
[[File:Pfanne (Edelstahl).jpg|thumb|left|Stainless steel]]

[[Stainless steel]] is an iron alloy containing a minimum of 11.5% chromium. Blends containing 18% chromium with either 8% nickel, called [[18/8 stainless steel|18/8]], or with 10% nickel, called 18/10, are commonly used for kitchen cookware. Stainless steel's virtues are resistance to corrosion, non-reactivity with either alkaline or acidic foods, and resistance to scratching and denting. Stainless steel's drawbacks for cooking use include its relatively poor thermal conductivity. Since the material does not adequately spread the heat itself, stainless steel cookware is generally made as a cladding of stainless steel on both sides of an aluminum or copper core to conduct the heat across all sides, thereby reducing "hot spots", or with a disk of copper or aluminum on just the base to conduct the heat across the base, with possible "hot spots" at the sides. Typical 18/10 stainless steel also has a relatively low [[Permeability_(electromagnetism)|magnetic permeability]], making it incompatible with [[Induction cooking|induction cooktops]]. Recent developments have allowed the production of [[Ferromagnetism|ferromagnetic]] 18/10 alloys with a higher permeability.{{citation needed|reason=Are 18/10 alloys ever magnetic enough?|date=November 2019}} In so-called "tri-ply" cookware, the central aluminum layer is paramagnetic, and the interior 18/10 layer may also, but the exterior layer at the base must be ferromagnetic to be compatible with induction cooktops. Stainless steel does not require seasoning to protect the surface from rust, but may be seasoned to provide a non-stick surface.

====Carbon steel====
[[File:Pfanne (geschmiedet).jpg|thumb|right|Carbon steel]]

[[Carbon-steel]] cookware can be rolled or hammered into relatively thin sheets of dense material, which provides robust strength and improved heat distribution. Carbon steel accommodates high, dry heat for such operations as dry searing. Carbon steel does not [[thermal conductivity|conduct]] heat efficiently, but this may be an advantage for larger vessels, such as woks and [[paella]] pans, where one portion of the pan is intentionally kept at a different temperature than the rest. Like cast iron, carbon steel must be [[Seasoning (cookware)|seasoned]] before use, usually by rubbing a fat or oil on the cooking surface and heating the cookware on the stovetop or in the oven. With proper use and care, seasoning oils polymerize on carbon steel to form a low-tack surface, well-suited to browning, [[Maillard reaction]]s and easy release of fried foods. Carbon steel will easily rust if not seasoned and thoroughly dried after cleaning, and should be stored seasoned to avoid rusting. Carbon steel is traditionally used for [[crêpe]] and fry pans, as well as woks.

====Clad aluminium or copper====
[[Cladding (metalworking)|Cladding]] is a technique for fabricating pans with a layer of efficient heat conducting material, such as copper or aluminum, covered on the cooking surface by a non-reactive material such as stainless steel, and often covered on the exterior aspect of the pan ("dual-clad") as well. Some pans feature a copper or aluminum interface layer that extends over the entire pan rather than just a heat-distributing disk on the base. Generally, the thicker the interface layer, especially in the base of the pan, the more improved the heat distribution. Claims of [[thermal efficiency]] improvements are, however, controversial, owing in particular to the limiting and heat-banking effect of stainless steel on thermal flows.

Aluminum is typically clad on both the inside and the exterior pan surfaces, providing both a stainless cooking surface and a stainless surface to contact the cooktop. Copper of various thicknesses is often clad on its interior surface only, leaving the more attractive copper exposed on the outside of the pan (see Copper above).

Some cookware use a dual-clad process, with a thin stainless layer on the cooking surface, a thick core of aluminum to provide structure and improved heat diffusion, and a foil layer of copper on the exterior to provide the "look" of a copper pot at a lower price.{{sfn|Williams|1986|pp=9–10}}