Cookware and bakeware materials
The materials that comprise your cooking and baking equipment can make a huge difference in how the food turns out. A pan or baking sheet of inferior quality (which typically translates to one that's light and thin-gauged) can stew meat that you're trying to sauté, or can burn the cookies. Knowing the basics of materials used can help you choose equipment according to the task for which it's intended. To start with, let's discuss the term nonreactive, which refers to metals (such as stainless steel) that have no negative reaction to foods cooked in them. On the other hand, reactive metals like aluminum, copper and cast iron react detrimentally with certain foods, particularly those that are acidic, such as lemon juice, tomatoes and vinegar. The results include a metallic taste and discoloration of the food. In the case of copper, toxicity from verdigris can be a problem. Most copper and aluminum cookware is lined with a nonreactive metal to make it usable with all foods. Aluminum is moderately priced, sturdy and a superior heat conductor. It comes in light and medium weightsthe heavier the gauge, the more evenly the food will cook. Anodized aluminum, available in plain (matte or polished) or anodized (dark gray) finishes, is by far the preferred choice. It has undergone an electrochemical process that alters the metal's surface, to make it extremely hard, low-stick (though not nonstick) and almost nonreactive to acids (storing acidic foods in this cookware could cause a chemical reaction). These finishes are chip-, stain- and scratch-resistant but can spot and fade if cleaned in a dishwasher. Use a nylon pad (never steel wool) for cleaning; lighten oxidized surfaces by filling a pan with acidulated water and boiling for 15 minutes. Don't buy untreated aluminum cookware, which can darken and pit when exposed to alkaline or mineral-rich foods, and when soaked excessively in soapy water. It can also discolor some foods containing eggs, wine or other acidic ingredients. Because aluminum may be reactive and easily scratched, it's often combined with other metals such as stainless steel. Cast iron (ironware) is fairly inexpensive and it absorbs, conducts and retains heat very efficiently. There are two basic stylesregular and enameled. Regular cast iron requires seasoning, which gives it a natural nonstick finish and creates a surface that doesn't react with or absorb the flavor of foods. Clean cast iron pans by first wiping them with a paper towel or soft cloth and, if necessary, gently scrubbing with a nylon pad. Copper is very expensive but is heavy duty and has superior heat conductivity, which makes it perfect for cream- and egg-based sauces. Copper is typically lined with tin or stainless steel to keep it from interacting with certain foods. The drawbacks to copper are that it isn't nonstick, requires polishing, and needs to be relined every 10 years or so (with average home usage). Still, it's the cookware of choice of many professionals. Never buy unlined copper pans, which can produce potentially toxic reactions with acidic ingredients like wine, lemon juice and tomatoes. Wash copper in hot, soapy water and dry immediately; brighten with copper polish. Earthenware isn't a good heat conductor but, because it retains heat well and releases it slowly, it's good for long-cooking dishes, such as baked beans and stews. It can be unglazed or glazed with a hard, nonporous coating. High-fired earthenware is hard and durable; low-fired versions are more fragile. Care must be taken to cool earthenware slowly and completely before washing in order to prevent the glazed earthenware from cracking. Most glazed earthenware can be washed in the dishwasher. Unglazed earthenware (also called clay bakers) are porous and must be thoroughly soaked in water before each use. Enamelware can be either cast iron or steel cookware that has been coated with thin layers of brightly colored porcelain enamel. Enameled cast iron is a good heat conductor; enameled steel is not. Enamelware is fairly easy to clean and doesn't interact with acidic ingredients. Light-colored enameled surfaces don't brown food as well as those that are dark and will also eventually discolor with use. Extreme overheating may cause the enamelware surface to crack. Because abrasives can scratch the enamel coating, use wooden or plastic utensils when stirring and a nylon pad when cleaning. Glass, glass-ceramic and porcelain don't conduct heat well, but retain it efficiently, which means they're good for long-cooking dishes at medium heat. The combination glass-ceramic dishes can go from freezer to oven with no problem; whereas glass and porcelain dishes can break easily with sudden temperature changes. All three are nonreactive and easy to clean. Nonstick cookware and bakeware has a special coating fused to interior surfaces. This coating allows for fat-free cooking, prevents food from sticking and requires minimal cleanup. Some nonstick finishes are applied to the surface and can wear off over a period of time. Others are bonded right to the metal, making for a sturdier finish (and a higher cost). Most nonstick finishes are dishwasher safe but require the use of nonmetal utensils to prevent surface scratching. Stainless steel has poor heat conductivity, a problem somewhat reduced in well-made, heavy pans. But it also has many advantages: it doesn't react (as does some aluminum cookware) with acidic or alkaline foods; it is corrosion-resistant; it's strong and easy to clean; and it doesn't easily scratch, pit or dent. The best of all possible worlds is clad metal stainless cookware with a core of either aluminum or copper (both are excellent heat conductors) sandwiched between two thin sheets of stainless steel. Stoneware is strong, hard pottery that's usually fully glazed, then fired at very high temperatures (around 2,200°F). It's generally nonporous, chip-resistant and safe to use in both microwave and standard ovens. It's ideal for baking and slow cooking.
From The Food Lover's Companion, Fourth edition by Sharon Tyler Herbst and Ron Herbst. Copyright © 2007, 2001, 1995, 1990 by Barron's Educational Series, Inc.