This is a transcript of the Gastropod episode Out of the Fire, Into the Frying Pan, first released on June 19, 2018. It is provided as a courtesy and may contain errors.

PATRICK MAHER: So once the pan is pressed then there’s still some deforming that occurs around the edges and so we heat it up and and then hammer that out by hand.

[HAMMERING SOUND]

TWILLEY: OK, clever people. Any guesses as to what is going on here?

GRABER: In case you just can’t figure it out, we were visiting a company called Blu Skillet to see a pan being made—by hand! From scratch!

TWILLEY: Which is not actually how any of my pans were made, but of course it used to be how all pans were made.

GRABER: You’re listening to Gastropod, the podcast that looks at food through the lens of science and history, I’m Cynthia Graber.

TWILLEY: And I’m Nicola Twilley. And today’s episode is sort of a natural segue from our last episode, all about ovens. This time, we’re all about pots and pans.

GRABER: Last episode, we told the story of taking fire and putting it in a box. But how did people first figure out that they should take meat or grains or plants and put those in cooking containers, too?

TWILLEY: What on earth does a humble cast iron pot have to do with launching the Industrial Revolution? Will cooking in a nonstick pan give you cancer?

GRABER: And here’s a question that many of you have wanted us to tackle: There are so many choices—cast iron, copper, Le Creuset, All-Clad—what is the perfect pan for cooking your perfect dinner?

TWILLEY: It’s all in this episode, folks.

PRE-ROLL

MUSIC

KAREN BADGETT: Is it rolling?

GRABER: It’s rolling

BADGETT: Well, welcome to the studio. My name is Karen Badgett and this is—

MAHER: Patrick Maher.

GRABER: Karen and Patrick make pans at their studio in Ballard, in Seattle. I was actually given one of their pans as a birthday gift from my brother and sister-in-law, who live not too far away. I’d seen them at the Ballard Farmers Market and I fell in love. But I had no idea how they were actually made. This episode gave me a great excuse to find out more.

BADGETT: Patrick’s been blacksmithing for 25, 27 years, something like that. And my background is painting. So when we met date night was just spent in the studio making things—like, that was probably love. So we made the copper bowl and we made different little things and we just played.

MAHER: It started out with a few gifts—we just started making some gifts for family and friends.

TWILLEY: Then Karen asked Patrick to make a pot rack, just a simple thing to hang her pans from. So he did.

BADGETT: He was hanging the pans and I had a crepe pan from college and he was hanging it up and he’s like, this is just carbon steel. I was, like, whatever that is, I don’t know. And so he came down to the studio and made just a little pan

GRABER: She still has it—it’s the first pan Patrick ever made.

BADGETT: Oh it is just a tiny little pan, because basically what Patrick did was, he took a sheet of steel, he cut a circle out, and he took a sledgehammer and just you know—

MAHER: —heated the metal and forged it into a ring using a sledgehammer and a round slug.

BADGETT: You know, it’s just the perfect over-easy egg pan. And so everything just kind of came together and snowballed from there.

TWILLEY: Karen and Patrick started by making pans for friends and family.

BADGETT: We sent a pan home to Patrick’s dad and he called and they talked for an hour—like, it’s blue and it just makes eggs and they just slide around… like, his dad was so excited. And he hung up and he’s like, I’ve been doing this for 20 years, that’s the most my dad has ever talked about blacksmithing.

GRABER: Then they took their pans to the farmers’ market. Patrick says people walked by and did a double-take—like, what are these beautiful pans? Honestly, that’s exactly what I did. And so I was really excited to watch Patrick make one, starting from a flat sheet of metal.

GRABER: Whoa! It’s hot.

BADGETT: Yeah, so the forge is actually at 22 — 2400 degrees.

MAHER: So the pans just start as a disc and a solid round bar. And you know our idea wasn’t to make it as easy as possible. It’s probably the hardest way to possibly make a pan.

TWILLEY: Patrick starts this labor intensive process by squashing that disc with a power press.

SOUND OF POWER PRESS OPERATING

GRABER: It’s a huge black machine with a hollow metal bowl at waist height and a rounded piece of metal above the bowl. They’re like the positive and negative. The disc of metal gets squished between them. The end result is the rough shape of a pan. Then Patrick slides the pan into the blindingly hot forge.

MAHER: It heats up relatively quickly to where I can deform it.

GRABER: He starts to shape the edges of the metal into what are starting to look like the sides of the pan I have at home.

SOUND OF HAMMERING

TWILLEY: Then he starts making the handle

GRABER: First Patrick heats a rod of carbon steel in the forge. Then he lays it on the flat surface of a large machine called a power hammer. Patrick holds the red-hot rod with long-handled tongs and moves it backwards and forwards as the hammer methodically pounds. The glowing carbon steel rod starts to deform and flatten into a basic handle shape.

SOUND OF POWER HAMMER

GRABER: Patrick takes the flattened rod back to the forge to get it hot again. Once it glows, he picks up a hammer and starts to shape it by hand.

BANGING SOUNDS

GRABER: My regular cast iron pans have a handle that kind of juts out at a bit of an angle. But on my Blu Skillet pan, the handle is textured from Patrick’s hammering. And it curves up from the pan before flattening out just a bit in the perfect dip to fit your hand.

MAHER: Yeah, so when we were designing this we were really kind of trying to get a nice elegant, you know, shape out of the handle. So it’s pretty thin kind of where it attaches to the pan but then it kind of gets wider as you go. It was more aesthetic decision but it actually turns out that it also helps.

BADGETT: Yeah, the heat won’t go up the handle, it’ll just stay right at the neck.

GRABER: Finally, Patrick rivets the handle onto the pan’s body.

TWILLEY: The end result of all this pressing and heating and hammering is a pan. An expensive, hard to get hold of pan—Patrick and Karen can only make so many and they sell out really quickly. But it is beautiful.

BADGETT: I mean, basically, this is a pan that is made to last—that you can pass down to your kids.

MAHER: I think for us to it is it was the idea of making just a beautiful object that also functions really well.

BADGETT: I mean, it fits really nicely in your hand, I love the way it feels.

MAHER: It’s a combination of form and function…

GRABER: They also admit that their process, making each pan by hand, it is a kind of ridiculous way to make a pan. Today, it’s a luxury to be able to own a handmade pan, as gorgeous as it is. And ,yes, it absolutely does the job perfectly on the stovetop.

TWILLEY: It’s true. Your Blu Skillet pan *is* amazing, Cynthia. But actually, all pans are amazing.

GRABER: Because, really, the invention of pots and pans completely transformed our relationship to food.

BEE WILSON: I think pots, first of all, led to cuisine itself. To me, it’s the great beginning of cookery. I know we can say that barbecue and roasting and just sticking something in front of the fire…. Well, of course—fire was a pretty important breakthrough in human history. But cookery to me begins with the pot.

TWILLEY: It’s Bee! Bee Wilson! She most recently starred in our ovens episode, and now she’s back to talk pots and pans, which is a different chapter in her book, Consider the Fork.

GRABER: As we described last episode, fire and cooking allowed us to eat for only an hour a day, not six hours a day, and so we could use all that extra time and energy to become super smart humans, capable of blacksmithing and art!

TWILLEY: Cooking made us human. But to heat food, you need more than fire. You need tools. To cook an entire chunk of an animal, it was often enough to stick a spit through it and rotate it in front of the fire. But lots of things can’t be stuck on sticks. So you need some kind of container for them.

GRABER: Bee says one of the best ways to understand how important pots were is actually to look at an early form of an oven, the pit oven.

WILSON: In a way, when you think about how elaborate pit cookery is, it makes you see just what a brilliant invention the cooking pot is, because this is the lengths that people had to go to if they wanted to achieve the same effects that we can now achieve very easily with a pot.

TWILLEY: You can still see pit ovens in action today, if you’ve ever been a Hawaiian luao.

GRABER: Or a New England clambake.

WILSON: Essentially, you dig a huge pit in the ground and you fill it with some rocks and maybe some leaves and then you get some hot rocks that you’ve made hot by heating them up in the fire and you lift them into this pit using tongs or some other device.

TWILLEY: Basically, you’re enclosing the food to cook it—really, you’re using your pit as a pot. But, as Bee says, it’s a lot more hassle than just getting a pot out of your kitchen cabinet.

WILSON: It would be extremely difficult to produce a hot rock pit like that all by yourself. So it’s a way that communities and villages would cook all together.

GRABER: Okay, so a clambake functions sort of like a pot, but it’s not really a pot. So what were the original pots?

TWILLEY: Before the invention of pots, people seem to have used anything that was vaguely pot shaped as a pot

WILSON: There are theories that people used shells but then you kind of picture something like a mussel shell or even a turtle shell and it would it be pretty hard to cook anything in a mussel shell except for a mussel itself. I think a more plausible candidate is animal stomachs of various kinds. That seems like a pretty good cooking bag that you could use lowered into water—and indeed that’s still what the Scottish delicacy haggis fundamentally is. But none of these was as versatile or as brilliant as what you could do once people discovered pottery.

GRABER: People discovered pottery a really, really long time ago. The very oldest seems to be about 30,000 years old.

JULIE DUNNE: I mean, one of the really interesting things about that is that pottery is invented independently in all sorts of regions around the world. And it is the first man-made technological invention.

TWILLEY: This is Julie Dunne—she’s a biomolecular archaeologist at the University of Bristol and she studies really old cooking pots.

GRABER: Julie told us that some of the earliest examples of pottery archaeologists have found are figurines. There are clearly lots of things you can make using fired clay. But when did people realize you could use that clay to make a pot?

DUNNE: So what we surmise—and this really is only a surmise—is that perhaps people maybe realized some day that they could actually seal a basket with clay and that would give you a really hard layer inside the basket and would make cooking easier. And maybe then it’s really just a small step to making a vessel that you can then put in a fire for a prolonged period of time.

TWILLEY: The very oldest cooking pot that archaeologists have analyzed comes from about 16,000 years ago. It was used for making fish soup.

DUNNE: So interestingly in China and Japan, the earliest pottery—that was actually used by hunter gatherers. Then in North Africa what we see is the invention of pottery for a completely different purpose, which was for cooking of plants.

GRABER: Julie actually excavated this North African pottery from a site in the Sahara desert in what’s now Libya.

DUNNE: It was actually the most amazing site. If you think of the Sahara now you probably think of this very dry, arid environment where not much in the way of either plants or animals survive.

GRABER: But ten thousand years ago, the region was a green savannah, like you’d see today in Kenya—archaeologists call it the Holocene Green Sahara.

DUNNE: There were lots of large water bodies, lots of wild grasses, stands of trees, and really large game animals.

TWILLEY: Nearby, there’s rock art showing giraffes and hippopotamus and elephants and crocodiles. But it turns out that’s not what the people who lived there were mostly using their pots to cook.

GRABER: Julie gathered the broken bits of pottery from the site—there were more than a hundred pieces—and she took them back to the lab for analysis.

DUNNE: What we do is we look at something called lipids which are preserved in pots. And lipids are essentially the fats, oils, and waxes of the natural world.

TWILLEY: These lipids can come from meat, fish, dairy, or plants—anything we eat, basically.

DUNNE: If you think about a cooking pot, what happens is, if you put something in it, a piece of meat and add some water and boil it up, what you’ll see on the surface are literally globules of fat. And of course these earliest pots weren’t glazed, there’s nothing to stop them mobilizing into the vessel. And by this most amazing serendipity they are actually the perfect size to fit within the ceramic matrix and therefore they have literally preserved for thousands of years, up to about 16 to 18,000 years.

GRABER: Which is genuinely mind-blowing. And fortunate.

TWILLEY: Because once Julie and her colleagues extract these perfectly sized lipids that have been protected and preserved in the pot walls for millennia, they can analyze them and figure out what, roughly speaking, they come from. They use a technique that was actually invented about 30 years ago, in the lab that Julie works in. And it’s revolutionized our understanding of what ancient people were cooking and eating.

GRABER: Julie found that about 30 percent of these pots from the Sahara had evidence of animal fat in them. That’s to be expected, people have been cooking meat as long as we’ve been cooking over a fire. But what was truly fascinating for Julie is that most of the pots had lipids from cooked plants. And this is the first evidence anywhere for plants cooked in a pot.

TWILLEY: Based on what was in the environment, Julie suspects that the plants in the pot were leafy stems from sedges, which grow in marshes and at the edge of lakes.

DUNNE: And it just seems that—although we do see some processing of animal products—it just seems that their early pottery was really invented to, as I say, make these plants easier to cook.

GRABER: Julie’s discovery highlights a moment in time where people in North Africa are moving from cooking over a fire to cooking in pots. And it’s a really important moment. Because these pots open up a world of food that the people who were living there couldn’t have eaten before. These sedges had been basically inedible before the invention of clay pots.

DUNNE: What pots do is they enable you to boil things for a prolonged period of time. It means you release more starches, which gives you more carbohydrate and so on.

GRABER: Imagine—suddenly the people living in what’s now Libya—they had a whole new food group on their doorstep! It’s like finding a gold mine in your backyard.

TWILLEY: Wherever people were in the world, there were some plants in their environment that wouldn’t have been edible until you could subject them to the kind of extended cooking that pots made possible.

GRABER: Some tubers are toxic until you cook them. Take cassava—it takes some processing and long cooking before it’s edible. But once cooked? It’s delicious. And lots of underground roots and tubers like yams are really difficult to eat unless you cook them for a long time.

DUNNE: So that’s what pots enabled them to do. It also enhances storage. So things keep for longer if you boil them—you get rid of bacteria.

TWILLEY: There are more advantages.

DUNNE: If you can soften foods like, for example, grains and so on, then you could start weaning children earlier.

TWILLEY: That means women can get pregnant again sooner.

DUNNE: And, for example, so for the first farming communities that would have meant more children, which would have enabled sort of expansion and this probably led to the first villages and so on. And the other thing that cooking things does is it makes them taste nicer.

GRABER: So Nicky, when you and I started talking about ancient pots, I had this theory that it took the invention of pots to give rise to different cuisines around the world—a whole world of distinct types of dishes. And it turns out that Bee agrees.

WILSON: Because it’s the first time you can have this calm intermingling of ingredients. And yes, you’re right —I do think the pot is—it’s the beginning of cooking and it’s the beginning of diverse cooking.

TWILLEY: And as part of that development of different cuisines, intermingling different local ingredients, you start to get different pots and pans—all kinds of shapes, and sizes, and materials. That’s my next question—how did we get from Julie’s ceramic pots to the wonderful array of cast iron skillets and Le Creuset casseroles and Teflon pans in my kitchen cabinet today?

MID-ROLL

GRABER: Part of the reason that there are so many different pots and pans is that their particular shapes make them better suited to different types of cooking. Shallow and flat pans are good for frying, larger and deeper are better for simmering. But there’s another aspect of pot shape.

SARA PENNELL: They would have been tailored to the fire you were cooking over. So quite a lot of round bottom pots, hanging pots, in metal—brass, bronze.

TWILLEY: This is Sara Pennell again—like Bee, she joined us last episode to talk about ovens and now she’s back to talk pots and pans.

GRABER: The great pots Sara’s describing for your cooking hearth are like cauldrons. These are pots that hang from a whole contraption with an arm that could swing that big, round-bellied pot to come to rest directly over the fire. Pots didn’t need flat bottoms, because they weren’t sitting on anything.

PENNELL: One of the ways we know about this before around 1750 in England is through the use of probate inventories—so the lists of chattels taken when someone dies. And, as you start to see coal becoming a much more commonly used kitchen fuel, you also start to see changes in the shape and naming of vessels used around the kitchen hearth or associated with the kitchen hearth.

TWILLEY: The great pots—those big, round cauldron style pots that work best over an open hearth—they began to die out when coal came. So did the smaller pots with their own little legs so that they could stand in the fire. They were called pipkins, which is adorable.

GRABER: Like Sara said in our last episode, coal fires are much hotter and smaller, and people put grates on top of them and to the sides for cooking. So the great pots and the pipkins were gradually replaced with a newfangled, flat bottomed arrival called… the saucepan.

TWILLEY: A saucepan is so normal—like, you really can’t even have a kitchen without a saucepan today—that it’s kind of hard to believe it was ever a novelty. But Sara says the word saucepan didn’t even exist in English until 1686.

PENNELL: It’s obviously associated in the sixteen hundreds with French cookery—that sort of, you know, nouvelle cuisine of the middle of the 1600s, with saucing and made dishes and so on.

GRABER: Sara’s point is that the pot changed shape because the fire changed—but then that change in pot shape changed what people cooked. All of a sudden, Brits are making intriguing, sophisticated new French sauces like one made out lemon, anchovy, and butter.

TWILLEY: It’s funny—I don’t think of my saucepans as being explicitly for making sauces—I boil water for pasta and make oats and do everything in them. But, of course, sauce pan—it’s in the name.

GRABER: When we say the word saucepan, like we’re doing repeatedly right now, I actually have to think hard about what they are, because to me they’re just my pots.

TWILLEY: At any rate, the saucepan was the hot new pot in town in the late 1600s, at least in England. The next great moment in pot history, so to speak, comes in the British midlands in the early 1700s, on the eve of the Industrial Revolution.

GRABER: This story revolves around one special pot and Richard Williams, the metallurgist who unraveled its secrets.

RICHARD WILLIAMS: Well, this first iron pot probably holds about 3 liters of liquid, of water.

GRABER: Richard’s iron pot is an old school pot, with 3 legs so you could place it in the fire.

TWILLEY: This sounds like a pipkin to me.

GRABER: Like everything in kitchens, people carried on using their old pots even as the new, flat-bottomed saucepans were catching on.

WILLIAMS: And the beauty about it is that it’s got cast into it the year in which it was made—1714. It appears to have been made as a celebratory gift or something like that, for a wedding.

TWILLEY: And this cast iron pot was part of the collection of Coalbrookdale Museum in the Ironbridge Gorge, a World Heritage Site in Shropshire.

WILLIAMS: Now I asked myself how this pot had been made. And I realized that it held the secret of how the Industrial Revolution had started, which was just five years previously.

GRABER: Last episode, we told you that when the Industrial Revolution was starting, in the early 1700s, England was also going through a wood famine. They’d used it all up. So they started turning to coal to heat their homes and their new ovens. They also used coal to heat glass and metals, basically everything they’d been using charcoal from wood for beforehand.

WILLIAMS: But iron was much more difficult.

TWILLEY: And iron was really important. When you use coal to make iron, instead of charcoal, the iron turns out really brittle—it’s no good for pots and pans at all. Your iron pot would break right away.

GRABER: People in continental Europe had figured out a workaround—they heated up sand-based molds for the iron. That added just the right amount of silica to make the iron less brittle and more useful. But these pots were made far from England and it took a lot of energy to heat up the molds. So they were quite expensive. Poor families often only had just one pot.

TWILLEY: And then, in 1709, a man called Abraham Darby figured out that if he used coke, instead of coal—coke is basically purified coal—if he used that, the iron would turn out malleable and strong. And this malleable strong iron—if he poured it into a mold, he ended up with a pretty awesome strong but light pot.

WILLIAMS: He patented the sand molding of pots in 1707, and then relocated to Coalbrookdale in Shropshire to make them

GRABER: So this is great, Abraham Darby is making pots, and they’re a lot cheaper, and everyone can have pots! Hooray! But that’s not all Abraham Darby did.

TWILLEY: He made pots, lots of pots, but at the same time, he played around with the iron-making process and casting techniques, figuring out little tweaks and improvements.

WILLIAMS: Only three years after Darby’s business was set up, Thomas Newcomen built the first ever steam engine. Initially mostly out of expensive brass. But by the 1720s, Darby’s company had advanced enough to be able to make pipes and cylinders for it

TWILLEY: Basically, the cast-iron cooking pot business that Abraham and his son ran in Shropshire—it funded the R&D for the industrial revolution. They made the first iron rails, the first iron bridge. They made the first iron aqueduct for the canals. All of this out of cast iron.

GRABER: Needless to say, Abraham and his family became quite well off. And their influence? Well, just look at the industrial revolution.

WILLIAMS: The Industrial Revolution defines the way we live now. The greatest change in human existence really since hunter gatherers became farmers, I think.

GRABER: Thanks to a cooking pot.

TWILLEY: The not so humble pot. So, we’ve gone from the invention of pottery to the Industrial Revolution. It’s time to bring the story of pots and pans into the 20th century.

MID-ROLL

WILSON: Yeah, it’s strange. I mean, as so often with kitchen inventions, Teflon was discovered as being useful for something completely different.

TWILLEY: It’s the 1930s. Chemist Roy Plunkett had just started work at DuPont’s lab in New Jersey. His first assignment was researching these fancy new CFC refrigerants, which at the time every one thought were the cat’s pyjamas.

GRABER: Of course now we know that CFCs led to holes in the ozone layer, and they’re since been banned. But back in the 30s they were pretty cool.

TWILLEY: Literally. So Roy was storing one of the ingredient to make CFCs—this gas called TFE or tetrafluoroethylene—he was storing it in cylinders on dry ice. And then he goes to get the gas out, and it’s gone—but in its place is a white powder. So he studies that instead.

GRABER: And this new white powder turned out to have some interesting properties. It was slippery, it was heat resistant, it was inert, other substances didn’t bond to it. This new chemical was called poly tetrafluorethylene, and for the first couple of decades it was used entirely for military and industrial purposes.

WILSON: And it was really only applied to cookware because this French engineer called Mark Gregoire, supposedly his wife said, Why don’t you take this PTFE or polytetrafluoroethylene—could that make a better pot for me? Because she like every cook was annoyed by the problems of sticky things getting stuck to her pans. And sure enough he attempted bonding it onto a pan and it seemed to miraculously make stuff just almost be repelled by this substance. And almost immediately in the 1960s, people in America went wild for Teflon as that then became called. And they were selling huge numbers of pans every month.

TWILLEY: Teflon works because its molecules are structured in a particular way that means they hate interacting with anything else.

HAROLD MCGEE: And so it tends to cause water and things like that to bead up and resists having things stuck to it.

GRABER: Yes, that’s food science guru Harold McGee again. And Harold says this property of Teflon can be incredibly useful in the kitchen.

MCGEE: Well the huge advantage is that it is a really good non-stick surface. So if you’ve got a fresh pan—a fresh Teflon pan is in my experience anyway unmatched when it comes to avoiding sticking. You can crack an egg right into it and—with no oil—and it’ll just slide right out. Which can sometimes be a problem. I can remember giving my son as a present a new non-stick pan because he loved to make omelettes.

GRABER: And he makes his first omelette—he’s bringing it over to the table—

MCGEE: And let the pan tip just the slightest bit. And it just slid right out onto the floor.

TWILLEY: Almost immediately after Harold told us this story, I made a beautiful spinach ricotta tart in a nonstick tart tin and experienced the exact same tragedy. The tart just slid right off the base and landed face down on the countertop. Thanks Roy Plunkett!

GRABER: At my place, we do have some nonstick tart pans, like the one you were using, Nicky. But my partner Tim does most of the baking. And I have to admit that I never bother using a nonstick pan—even for eggs. I just add more oil to my Blu Skillet. Bee’s the same.

WILSON: I never use non-stick pans now. I don’t have a single one in my kitchen. And it’s partly those doubts that crept in about Teflon and people saying was it quite safe?

TWILLEY: There’s really two separate sets of doubts here. One is, are the pans themselves dangerous?

GRABER: Harold told us that they can be, if the Teflon coating breaks down. That starts to happen at about 500 degrees.

MCGEE: And if you by mistake leave the pan on on high heat and forget about it so that the pan overheats it generates toxic fumes.

GRABER: But 500 degrees is really, really high. So the pan has to be both totally dry and subject to like the hottest flame on your stove top. It’s not a real problem with normal cooking.

TWILLEY: Another thing people worry about is flakes of the nonstick coating getting into their food. But like we said, the chemicals are totally fine until they get to 500 degrees. So those flakes are not a problem.

GRABER: Now the second big concern: the manufacturing of the pans.

TWILLEY: One particular chemical that was commonly used in the process of making a nonstick surface is called something long and complicated, or PFOA for short. We asked David Savitz, who is professor of epidemiology at Brown University, whether this is something we should be worried about

GRABER: David’s involvement with Teflon came about because of PFOA. But the issue he was researching is a much more serious one than the potential risks of accidentally overheating your pan.

TWILLEY: It turns out that making Teflon, at least the way it used to be done, released lots of PFOA into the groundwater. And that PFOA ended up building up in the blood of the folks who lived near the factories. And that’s where David comes in.

DAVID SAVITZ: It was a class action lawsuit filed in the Mid-Ohio valley in Ohio and West Virginia, in relation to a DuPont manufacturing facility that’s located there.

GRABER: Again, this isn’t just because of pan manufacturing. Teflon was being used in much larger quantities for non-cooking purposes. But, as part of the settlement in 2005, David was recruited to join a three-person scientific panel. He and his colleagues were charged with figuring out whether PFOA did in fact have a health impact on the people who lived near the manufacturing facility.

SAVITZ: First of all, as we started the work it became clear very early on that we knew almost nothing about health effects of PFOA. Which is kind of unusual.

TWILLEY: The panel’s research was supposed to take 2 years—it took 7. They ended up reviewing the medical histories of 16,000 people, they published 35 peer reviewed papers—it was a huge huge undertaking. Kind of groundbreaking in terms of pollution science.

GRABER: The panel found that almost everyone in the U.S. has some PFOA in their blood. They also found what they call probable links between elevated levels of PFOA and a number of health conditions: colitis, kidney cancer, testicular cancer, thyroid disorders, elevated cholesterol, and a pregnancy condition called pre-eclampsia. But again, these are probable links, David says it means it’s just slightly better than chance that PFOA could cause these problems. 51% instead of 50-50.

TWILLEY: Truly demonstrating that exposure to a particular chemical is linked to chronic conditions—it’s just really hard.

SAVITZ: You know these take very large studies and long follow-up of populations. And those findings from our study still stand alone. They haven’t been contradicted. but you know they haven’t been corroborated either .

TWILLEY: In any case, DuPont and other manufacturers decided they would phase out PFOA. For more than a decade now they’ve been making nonstick materials using alternative chemicals

SAVITZ: And over that time the levels in the environment and the levels and in people’s blood, you know, based on national data, have gone down quite substantially.

GRABER: That sounds good. But of course we don’t know the impact of the replacement chemicals yet. David says one aspect of the new nonstick chemicals that seems to be better than PFOA is that they don’t seem to stick around in the environment as long. Which would be an improvement.

TWILLEY: So where does that leave me and my nonstick pans? I turned to Harold for some words of wisdom.

MCGEE: Well, you have to think about the lifetime of the pan, the making of the pan, and then just be really careful with it once you’ve got it.

GRABER: I personally just don’t want to bother. I know in the scheme of things it’s not a huge deal, but I guess I’d rather have a pan that gets better the longer I use it. I seem to be on the same page as Bee here.

WILSON: The test of a really good pan is that the more times you grease it and heat it develops a wonderful patina that only gets thicker and lovelier and more non-stick as time goes on. And just wouldn’t you rather something that ages gracefully like that than a non-stick pan that just becomes progressively less?

GRABER: Exactly.

TWILLEY: Sure but scrambled eggs! We are going to disagree on this one, Cynthia. But I think we can all agree that the 20th century miracle of Teflon is not the secret to *the* perfect pan. So what is?

MCGEE: Well, the ideal pot or pan would be a material that is lightweight so that you can handle it easily, and heats quickly and evenly so that you don’t get hot spots and doesn’t stick to the food or doesn’t let the food stick to it.

TWILLEY: Sounds like a challenge!

GRABER: Let’s see if we can design the perfect pan. First up, let’s try to make it lightweight.

TWILLEY: I have just the material for you!

MCGEE: Aluminum is light and it’s also a very good conductor.

GRABER: But aluminum reacts with foods like tomatoes and eggs and vinegars and citrus and the food ends up tasting bad. And aluminum dents easily. So, not perfect.

TWILLEY: But, like Harold said, it is a good conductor. And the perfect pan needs to heat quickly

GRABER: Ceramics or clay pots, those heat really slowly and then hold on to that heat. Great if you’re sticking a clay pot in an oven, not so good on the stove top.

MCGEE: Copper is the best conductor of the of the standard culinary materials. I did once have someone send me a silver pot, which is—silver is even better than copper is and it was very nice but yeah—not a practical sort of thing.

GRABER: Great! Copper it is.

TWILLEY: Not so fast. Copper is not perfect either.

MCGEE: It’s expensive because we use billions of miles of it in wires and all kinds of other things.

TWILLEY: Plus, like aluminium, copper is very reactive—it reacts with different foods and makes them taste bad. Plus it can be poisonous, which I think is a disqualification.

GRABER: To be safe, people have coated copper pans with tin to make them less reactive, but tin melts at a relatively low temperature, so they can’t go in the oven. And then eventually the tin wears through, and you have to get the pan retinned. So copper isn’t the perfect material after all.

TWILLEY: How about we tackle this problem from a different angle? The perfect pan should heat evenly, and Harold has a test for this that you can easily try at home.

GRABER: Harold puts circles of weighted-down parchment paper on his pots and pans as he heats them up on the range.

MCGEE: And what you’ll see there is the parts of the paper that have been heated hot enough to get brown will be brown and the rest will still be white. And that gives you a very direct image of where the heat is going.

TWILLEY: Because Harold is slightly crazy in the best possible way, he has actually done this for all his pans at home

MCGEE: I have examples of all different sorts of pans and I figured that a cast iron would do very well because cast iron has a reputation for heating evenly. And I discovered that cast iron pans were the pans that heated least evenly of my batterie de cuisine.

GRABER: Harold’s pans that heated the most evenly were ones that had layers of different metals sandwiched together to end up with something lightweight AND conductive AND durable. In America probably the best-known example of this is All Clad.

TWILLEY: I love my All Clad. LOVE

GRABER: Me, too. For most people, these are their favorite types of saucepans.

TWILLEY: This sandwiching technique to get the best of all possible worlds goes way back—like Cynthia said, people would put layers of tin on their copper pots to stop them being so reactive and they’d put a layer of enamel on their cast iron to make it more nonstick.

GRABER: But that enamel layer isn’t really nonstick. And that’s the next thing on Harold’s perfect pan list.

TWILLEY: But we’ve already discussed the flaws of normal nonstick. Are we stuck?

GRABER: Haha. Not totally. Both cast iron and carbon steel can become slippery as you use them.

TWILLEY: Cast iron and carbon steel are both iron. They’re almost chemically identical—they’re the same metal, it’s just that they have a slightly different crystal structure.

GRABER: Cast iron gets poured into molds, not hammered into shape by a machine or a blacksmith, as carbon steel is. But the point is, both can become nearly nonstick when they’re well seasoned.

TWILLEY: Ah, the mysteries of seasoning your cast iron. I know it involves fat and heat, but what is actually happening to the pan when you season it?

MCGEE: First of all, you end up filling the microscopic pores that exist in the surface of even what looks like a smooth metal pan. But then you also end up causing the fat molecules to break apart and polymerize with each other to bond to each other, into a layer that is again not perfectly strong or impermeable but at least offers you some insulation between the food and the pan surface.

GRABER: There is a lot of anxiety on the internet and among our listeners about how to season your pans. How to get those fat molecules to bond together and form that lovely layer that makes the pan slippery.

BADGETT: So basically what a few people do is make it more complicated than it really is. A lot of people will try to—you know, they do the layers and layers where they’re baking on layers. I’m like, Oh my god, what? You know? So basically like we do it once and we’re done.

GRABER: Karen and Patrick season their Blu Skillet pans before they sell them. But if you cook a lot of something acidic like tomato sauce in your pan or if you scrub the layer of seasoning off, here’s what to do. Wipe it totally clean of oil, put it in a really hot oven for an hour. When it comes out, Karen says to scoop in a blob of coconut oil, tilt the pan around, and let the oil sit as the pan cools down. That should do it.

TWILLEY: But let’s haul ourselves out of our seasoning rabbit hole here. The whole point was we were looking for the perfect pan. Is there such a thing?

MCGEEL I’m afraid not.

WILSON: The thing is we look for all these different things in pots and pans, and lots of them are completely incompatible. And this was really brought home to me when I came across the work of this brilliant American engineer called Chuck Lemme, who systematically just went through and tried to identify what an ideal pot would be. And he rated them out of 1000.

GRABER: Chuck scored the pots for the same things Harold was looking for in a perfect pot. He gave points for how well pots conducted heat, how likely they were to dent if you dropped them, how non stick they were…

WILSON: And he found that the highest score he could find for anything was only 544 out of 1000, which he gave to cast iron. And that’s only just over 50 percent. That’s a hopeless score. And really the conclusion to reach from this is that we should all just be happy and realize there’s no such thing as the ideal pot. The ideal pot would be very, very thin and very, very thick at the same time. In other words there is no ideal pot. Life isn’t perfect. We should just accept and be grateful for the various pots that we have and it’s all a trade off.

TWILLEY: And our pan quest is over. Thank you Bee, for helping us snatch victory from the jaws of defeat. The point is pots and pans are much more than just their particular properties—they are fundamental to our relationship with food, which is fundamental to who we are.

GRABER: That’s true on a macro level—in terms of the development of eating and cuisines over human history. But it’s also true personally. We end up creating a relationship with pots and pans that goes beyond just how perfectly they conduct heat or how well they brown our potatoes or how beautifully the stew bubbles inside.

WILSON: When we talk about pans, we’re almost too utilitarian.We’re talking about, will it heat evenly. Is it going to retain heat? Is it going to conduct well? And then we kind of miss out this unquantifiable quality in pans, which is lovability. And to me, Le Creuset pans—I have two or three of them in my kitchen and I just love them. I am not sure if they do the best job of cooking. They are actually great for making slow-cooked casseroles but it’s partly the way they look on the table. They remind me of my mother in law who always cooked in blue Le Creuset. And it’s just the atmosphere of them—they look the way that I feel cooking should look

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TWILLEY: Go and hug your pots, people. And if all this history and science has left you hungry to find out the future of pots and pans—well, we’ve got that too. We’ll be telling that story in a special Stitcher Premium episode this summer—you can subscribe at stitcherpremium.com/gastropod and you get your first month free! We want to thank Patrick and Karen of Blu Skillet, Bee Wilson, Julie Dunne, Sara Pennell, Richard Williams, Harold McGee, and David Savitz. We have links to all their awesome work—carbon steel pans, research papers, and fabulous books—at gastropod dot com. Plus pictures of pans being made! Gastropod dot com is also where you can buy tickets to our live event in Miami and donate to support the show. So go there now. Please. And a final huge thanks to our all star volunteer Ari Lebowitz. She helped research this episode and much more besides. We’re taking a short break to work on a new season for you but we’ll be back on August 14.