Free Consider the Fork: A History of How We Cook and Eat by Bee Wilson

cure for baldness, a pan that cooks food without sticking is a universally sought-after invention. As of 2006, around 70 percent of the cookware sold in the United States has a nonstick coating; it has become the norm rather than the exception.
    But as the years went on, it became obvious that nonstick was not flawless. I’d never make a stew or a saute in nonstick, because when nonstick works, you get none of the browned sticky bits you need for deglazing. All too often, however, you have the opposite problem: the amazing nonstick properties do not last. Over time, no matter how carefully you treat it—shunning metal utensils, shielding it from searing heats—the nonstick surface of a PTFE-treated pan will simply wear away, leaving you with the metal underneath, which rather defeats the purpose. After too many short-lived nonstick pans, I’ve decided that it’s not worth it. It’s far better to buy a traditional metal like aluminum or steel or cast iron and season it with oil: that way, your pan gets better with use rather than worse. Each time you grease and cook with a cast-iron pan, it gets an extra patina. Whereas each time you cook with nonstick, the coating gets a little less slick.
    There are other reasons to pause before buying nonstick pans. PTFE is a nontoxic substance, but when heated to very high temperatures (482°F and above), it emits several gaseous by-products (fluorocarbons) that can be harmful, causing flu-like symptoms (“polymer fume fever”). When doubts first emerged about the safety
of nonstick pans, the industry replied that pans would never be heated this high under normal use; but by leaving a pan to preheat with no oil in it, it is perfectly possible to reach these temperatures. In addition, in 2005, the US Environmental Protection Agency looked into whether PFOA, a substance used in the manufacture of PTFE, was carcinogenic. DuPont, the main American manufacturer, has pointed out that the amount of PFOA remaining on a finished pan should not be measurable. But, whether fairly or not, many people have been left feeling uneasy about the miracle of nonstick surfaces.
    Faced with all these hazards, how is one to choose the right pan? In 1988, an American engineer named Chuck Lemme, cited as the inventor on twenty-seven patents that range from hydraulics to catalytic converters, decided to approach the question systematically. He looked at all the available materials and rated them in nine categories:
    1. Temperature uniformity (my translation: Will it even out heat spots?)
    2. Reactivity and toxicity (Will it poison me?)
    3. Hardness (Will it dent?)
    4. Simple strength (Will it survive being dropped?)
    5. Low stick rating (Will my dinner get glued on?)
    6. Ease of maintenance (Will it wash easily?)
    7. Efficiency (Does it conduct heat well vertically through the base?)
    8. Weight (Can I lift it?)
    9. Cost per unit (Can I afford it?)
    For each category, Lemme rated the materials, using a scale of one to ten. He then tabulated his findings into an “idealness rating,” with 1,000 as the perfect score.
    Lemme’s findings confirmed how difficult it is to produce perfect cookware. Pure aluminum rated very high for temperature uniformity
(scored 8.9, out of a possible 10)—great for evenly browning an omelette—but very low for hardness (scored 2): many aluminum pans end up misshapen. Copper was efficient (scored 10) but hard to maintain (scored 1). Overall, Lemme found that none of the “single material pots” rated above 500 in the idealness scoring; in other words, they landed just halfway up the scale. The best was pure cast iron (544.4). Those of us who continue to use cast-iron skillets are on to something. But 544 is still a low score.
    The only way to get closer to the ideal rating of 1,000 was to combine metals by sandwiching them together. At the time of Lemme’s investigation, the consensus among high-end cookware experts was that the only copper pans worth having were fashioned