The range of metal materials used in the cookware to make the pot is very narrow because the pot needs good thermal conductivity and stable chemical properties. Otherwise, the taste of the food will change. Many metals have good thermal conductivity, but their chemical properties are too unstable, so they are unsuitable for processing food. But in some cases, the pot can be made of a volatile metal material and then coated with a layer of other stable material.
Aluminum is a metal with excellent thermal conductivity. It will not rust and is resistant to many forms of corrosion. Aluminum cans will change the taste of food if they come into contact with some acidic foods. For example, vegetables such as egg yolks, asparagus, or sun thistle in a soup pot can cause the oxidation of aluminum that has not been anodized. Aluminum generally exists in the form of stretched, die-cast, or anodized aluminum. Stretched aluminum is formed by rotary stamping. Due to the soft nature of this metal, it is generally made into an aluminum alloy with magnesium, copper, or bronze to increase its strength. Stretched aluminum is widely used in baking sheets, juice boards, cake muffin pans, soup pots, steam pots, pasta pots, and even works.
Die-cast ones are often thicker than stretched ones, making them more suitable for soup, Dutch, and heavy baking pans. Since aluminum die-cast products produce tiny pores visible in the microscope during the die-cast process, the thermal conductivity of aluminum die-cast products is lower than that of stretched pots. Anodized aluminum naturally has a layer of aluminum oxide formed by electronic processing, which is hard and does not efficiently react with other substances. This technique is often used to make juice pots, chowder pots, baking pots, and Dutch baking pots.
Western cooking, the best pots in cookware and bakeware sets are made of a thick layer of copper with good thermal conductivity and a thin layer of tin (to prevent the copper from reacting with acidic food). A copper pan or copper pot can provide the best thermal conductivity, but it is heavier and more expensive and needs maintenance and recasting from time to time. They are the best materials for high-temperature heating and rapid cooking as a soup pot. Some restaurants still use tinned copper pots that are thicker and heavier, with good heat conduction but high prices.
Cast iron cookware heats slowly, but once the temperature rises, it can withstand the high temperature. So it is an ideal pot for heating at hot temperatures. As a reactive material, it is prone to chemical reactions with highly acidic foods. In addition, some foods such as spinach will turn black when cooked on red cast iron. Cast iron pots in Chinese cookware are porous materials that are easy to rust. As a result, the pot must be dried before use. Drying creates a thin layer of oil and carbon to protect the surface from sticking to the pot.
Stainless steel is an iron alloy containing a minimum of 11.5% chromium. It comprises 18% chromium plus 8% nickel, 18% chromium plus 10% nickel. Stainless steel is commonly used in kitchen equipment. The advantage of stainless steel is that it is corrosion-resistant, does not react with acid and alkali food, and is not easily scratched or dented. The disadvantage of using stainless steel for cooking is that it does not conduct heat well. Therefore, stainless steel pots usually have a layer of copper or aluminum on the bottom to conduct heat.
Carbon steel cookware can be rolled or beaten into a thinner material while maintaining high strength. It can be warmed by rapid high heat. Carbon steel cookware sets do not conduct heat as much as other materials, but this is also an advantage of being used as a wok and a paella pan: when one part of the pot is copper, the other parts are deliberately kept at a different temperature. Like cast iron, the carbon steel pot should be preheated and dried before use. Rub a layer of oil on the pool's surface and place the pot on the stove to heat it. After a period of use, the bank's surface will turn black and not stick to the pool.