Say Cheese Transcript (3)

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1 Say Cheese! by Cynthia Graber and Nicola Twilley, aired on Gastropod MUSIC HP: The very question we were to address is how is cheese made. Which I think that the postdocs who put together the questions thought that this was a straightforward question to begin with, but we went round and round. Because it turns out that you can't explain how cheese is made without knowing what you mean by cheese. JINGLE CG: You’re listening to Gastropod. NT: The podcast where we wrestle with the really big questions. Like: what is cheese, anyway? CG: Well, not exactly. It’s more like, here we are, putting out an episode about cheese history and cheese science and even how to put together the ultimate cheese plate, and it turns out we don’t actually know what cheese is! But we’re getting ahead of ourselves. I’m Cynthia Graber. NT: And I’m Nicola Twilley, and the lady who opened up this whole pandora’s box of how to define cheese was Heather Paxson. CG: She’s an anthropologist at MIT. She’s been studying cheese and the people who make it. She also was part of an American Academy of Microbiology meeting last summer, in June 2014. They were talking about the role of microorganisms in cheese. There’s a paper that came out of that meeting - we have it for you on our website. So Heather organized a cheese tasting for us, to help us to get to the bottom of what cheese actually is. HP: So for instance we were of course there to talk about microbes and cheese. And, in fact, the FAQ that came out of

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Cynthia Graber

Transcript of Say Cheese Transcript (3)

3Say Cheese! by Cynthia Graber and Nicola Twilley, aired on


HP: The very question we were to address is how is cheese made. Which I think that the postdocs who put together the questions thought that this was a straightforward question to begin with, but we went round and round. Because it turns out that you can't explain how cheese is made without knowing what you mean by cheese.


CG: Youre listening to Gastropod.

NT: The podcast where we wrestle with the really big questions. Like: what is cheese, anyway?

CG: Well, not exactly. Its more like, here we are, putting out an episode about cheese history and cheese science and even how to put together the ultimate cheese plate, and it turns out we dont actually know what cheese is! But were getting ahead of ourselves. Im Cynthia Graber.

NT: And Im Nicola Twilley, and the lady who opened up this whole pandoras box of how to define cheese was Heather Paxson.

CG: Shes an anthropologist at MIT. Shes been studying cheese and the people who make it. She also was part of an American Academy of Microbiology meeting last summer, in June 2014. They were talking about the role of microorganisms in cheese. Theres a paper that came out of that meeting - we have it for you on our website. So Heather organized a cheese tasting for us, to help us to get to the bottom of what cheese actually is. HP: So for instance we were of course there to talk about microbes and cheese. And, in fact, the FAQ that came out of it is titled Microbes make the cheese. And in many of the cheeses that first come to mind for instance, the cheddar that we have here on the table its a natural cheese. Its developed first by the bacterial fermentation of milk that allows for the curds to then coagulate and develop a natural rind on the outside, which contributes to the flavor and the character that we attribute to the cheddar, as opposed to another sort of cheese.So that was the kind of cheese that I think everybody had in mind but then as soon as we started talking, we people said, Well, what about ricotta? What about paneer? What about American cheese?

CG: Thats because ricotta, paneer, a goats milk chevre - those dont contain microbes at all! And American cheese? Well get to that crazy process later.

NT: I feel like this is the kind of thing people fight wars over. Or at least expensive legal battles. So what about ricotta? Is it a cheese?

HP: Ricotta is definitely a cheese.

NT: Phew. Case closed.

CG: Wait a second the plot thickens...

HP: There was a difference of approaches in the different working groups that we had at our meeting. And some really set out to come up with a universal definition. And the universal definition is basically that cheese is dehydrated and aged milk.

CG: that doesn't sound nearly as attractive!

HP: It really doesnt!


CG: In the end, basically, Heather said that the scientists decided that there were three different methods for making cheese. And the end products of each of those three methods count as legit cheese. So you can just use acid to clump milk proteins into curds. Thats the acid method, for things like cottage cheese. Or you can use acid and heat. Thats ricotta and paneer. Or you can use rennet and microbes, like for cheddar or brie or all the other things we think of as cheese. Rennets an enzyme that traditionally comes from the stomach lining of calves, though weve figured out other ways to make it these days.

NT: So basically, to get to cheese, you need to separate milk into solids and liquid, and you have three choices for how to do that.

CG: Its funny, though, if you taste ricotta

NT: Oh wait a minute, am I finally going to get to eat something on this show?

CG: Not only that, we are going to eat it eat together. In different states. Using a bit of complicated engineering, with us buying the same identical cheeses-

NT: Oh, poor us, double the cheese -

HP: It tastes like milk.

NT: It tastes like cream.

NT: Its really good. But you know, it is very delicate in flavor. Like there is none of that I mean, if you told me this wasnt cheese and you asked me to believe it was just thickened cream, I would accept that definition.

CG: Yeah, me too.

HP: Yeah yeah thats interesting. I mean, its fresh, right. It also hasnt been aged. So the microorganisms I mean, in a hard cheese we get the flavor from the microorganisms breaking down the enzymes and the fats in the milk, and releasing flavor compounds. And that doesnt happen with ricotta. Because its fresh and we eat it right away and there is no breaking down of the component parts. So its as good as the milk is.

CG: Whats crazy here is that the ricotta we just tasted might be something like very first cheeses ever made. Though those were from sheep or goats milk. I spoke to a cheese scientist and historian. His name is Paul Kindstedt, hes at the University of Vermont. He described the origins of the very first cheese.

PK: Well the earliest evidence and it's really fairly recent because of new analytical methods technologies that have enabled archaeo-chemistry to be carried out at levels never before. But the earliest evidence for cheese-making and large-scale dairying goes back to about 7000 6500 BC.

NT: We are going back to the very dawn of cheese. But before we go there - first were going to hear some of your cheese stories.


JENNY: Im Jenny Morber and here is my cheese story. My dad actually worked for Kraft foods when he was a young engineer hurting for money. His job as least from the stories Ive heard was to taste products that had gone a bit off, to see if he could tell what had gone wrong with the processing. Needless to say, we didnt have much Velveeta in the house, and he never ate mayonnaise. But we didnt have much else in the house either, cheese-wise. I still remember the time I taste brie from a supermarket in France. I was like, holy shit, cheese can taste like this? It was like I put on a pair of classes and could suddenly see the leaves. Yeah, I gained fifteen pounds that summer.

MIKE: Hello, Gastropod, this is Mike in Gainsville, Florida. I was calling to say I absoutely adore cheese. I was delighted when I discovered from my English wife that cheese is actually a course in an English dinner.

NT: So speaking as an English wife, I can say that this is just one of the many reasons why were the best! Heres another story - Emily Lo Gibson told us she started loving cheese thanks to Wallace and Grommit. But it didnt turn into a full on addiction until she spent a semester studying abroad in Paris. Enjoying her host familys nightly cheese course. MUSIC - WALLACE AND GROMMIT

NT: Back to the history. Cynthia, transport us back nearly nine thousand years to the very very very beginning of cheese.

CG: Heres what was going on. But actually I have to start back even earlier, by about a thousand years. Okay - so were in the fertile crescent, its the region that curves down through the Middle East, from Egypt on one side to Iraq and the western fringes of Iran and as far north as about southern Turkey. And why then? The climate had changed - it was the end of the last major ice age. Things are warming up. And people started growing all these crops. Its basically the dawn of agriculture. They start settling down and growing cereals that theyll eventually domesticate. And the local wildlife started showing up to snack on the crops.

NT: By which you mean things like goats and sheep.

CG: Right. And as we know, these animals can provide milk. The only problem is that was basically no use. Everybody was lactose intolerant. Except for the babies.

PK: Almost certainly in the early stages, we don't know when the first experiments with milking for human consumption took place, but almost certainly the milk was harvested for the very young children. Because humans would be very well aware that young children survive on milk. Until theyre weaned.

NT: OK, so now we have the start of dairying. But what about cheese?

CG: So it turns out that cheese begins because of the very first human-created environmental disaster.

PK: The soil fertility has been driven to nothing. Deforestation, erosion, lots of evidence of catastrophic environmental failure brought on by too many people and unsustainable agricultural practices that just couldn't support the population any further.

CG: But what the land could support was those animals that were hanging around..

PK: It's amazing how little it takes to raise in terms of vegetation - it takes to raise sheep and goats.

CG: And then one other thing happened at the same time that kick-started our whole incredible love affair with cheese - the Neolithic people invented pottery.

PK: Think about it you have to milk into a container and there were limited options for containers in the Neolithic. So pottery opened the door to collect milk on a larger scale and store it. And in the warm environment of the Fertile Crescent region, that milk would have almost immediately, very quickly, in a matter of hours, coagulated. Because of the natural lactic acid bacteria that is always present in the environment. And so acid coagulated curds or fresh cheeses would have just happens almost instantaneously. NT: Its ricotta!

CG: Or more likely chevre, because goats were domesticated before cows they were a lot smaller and friendlier.

NT: Cynthia, I know youre the one speaking to the expert here, but what I had always heard is that the very first cheese came about because a nomadic herdsman was riding around carrying milk in an animals stomach like some kind of proto thermos. Of course as we said earlier the stomach has rennet in it. So as he rode, the milk coagulated and by the time he stopped for a drink his milk had turned into cheese.

CG: Thats exactly what I thought. I actually wrote a science story on cheese more than a decade ago and I mentioned that story. But its totally not true because the herdsman would have been lactose intolerant. That milk, before cheese came around, it was only for the kids.

NT: Oops.

CG: Yep, I was wrong. Sorry. But I saw another article just a week or so ago and it had the exact same myth! So here we are. Busting the myth.

PK: The Neolithic peoples would have been confronted with this change in the milk magically going from a liquid to a gel and sort of pudding like consistency. And if they broke up that gel they would have seen that a liquid would separate and a solid curd could be recovered. And at some point probably very quickly some adventurous adult tried some of this curd and found that they could tolerate it a lot more of it than they could milk. Because the lactose content is reduced by about 80% in the process of coagulation and separation and fermentation.

CG: And heres whats totally crazy - eating cheese changed their DNA.

PK: Cheese-making in particular made dairying as a strategy available not just to very young children, which Neolithic people have been dabbling with for some time, we don't know how long. But now suddenly dairying became a viable survival strategy for the entire population because adults could consume cheese. And therefore dairying became part of life in general and milk was available and around. Children and newborns were being exposed to milk far more frequently which ultimately selected for through random mutations those children that could tolerate lactose into later childhood and into adulthood. And it's an absolute stunning example of genetic selection occurring in an unbelievable short period of time. Of time in human development. I mean this is really stunning stunning stuff. That humans could evolve and develop the tolerant selectors so quickly after the onset of dairying. It's really a wonder of the world and it changed the world forever, it changed Western civilization forever.

NT: Thats really kind of amazing. But that means that those cheeses that caused Heather and her microbiologist buddies such a headache the acid coagulated cottage cheeses and the acid heat ones like paneer and ricotta so those are actually the original cheeses.

CG: And really the most important cheeses. I mean, they literally changed our DNA forever. And whats more, they changed our entire civilization. Cheese ends up being at the foundation of cities and even writing, which kind of blew me away because it ends up being part of the very first religion. This is happening in modern day Iraq.

NT: So these are Sumerians.

CG: Exactly. Fast forward about three thousand years. People have been eating cheese for a while. Theyve created the first city-state. Its called Uruk. And it runs on cheese! And so of course their religion now runs on cheese! Heres a tale Paul told me about this goddess named Inana. She has to choose between two suitors - theres a farmer who wants to marry her. And then theres the shepherd, Demusi.

PK: And Demusi makes argument that what I can offer is so much better than what the farmer can. And I have milk and I cream and I have butter or butter oil. And I have cheese and I have flavored cheeses and yogurt and fermented milk. And I produce so much surplus of these products that even when I supply you with all you want and desire Ill have extra leftovers to give away. I can really keep you happy sweetheart.The long and short of it is Inana agrees to marry Demusi and gets won over because she really values the dairy products.

CG: And based on that belief, it starts a thing where people gain favor with the goddess by bringing her cheese and butter at the temple everyday.

PK: And the government basically the king and his ruling elite working in conjunction with the temple priests gain control over shepherds and create a whole contractual system to make sure that there are shepherds that take care of the sacred flocks and the sacred herds. And overseeing a system where dairy products cheese and butter would be coming into the temple every day and stockpiled and then go through a series of rites and rituals. And then they would be redistributed to the civil service who are running the government running the city.

CG: Managing all of that cheese was a bureaucratic nightmare. So whats they do? They invented writing.

NT: To keep track of the cheese! Its like the original management system! I love it. Who moved my cheese but 5000 years ahead of its time!

CG: Its a crazy story. When I was reading the book, sitting next to a friend, I literally exclaimed - the city-state was founded on cheese! I told Paul that story. He hedged and said there were other agricultural products as well. But cheese and butter played a major role.

NT: But, as we discussed with Heather, cheese has come a long way since those early days. So how did we get from that ricotta to all the cheddars and the bries and the Emmental that we know and love?

CG: And love so much. Were about to jump ahead again a few thousand years to the Middle Ages. Thats like the golden age of cheese invention.

NT: There were some things to figure out along the way. Trial and error. And in fact, as it turns out, cheese can still be quite a complicated thing to figure out today. We heard some funny stories about cheese mistakes from you guys. Roz Cummins was volunteering in the Boston food co-op many years ago. There was a hippie guy there who she worked with.

RC: And he said hey man, we just got some really good Gouda in from Amsterdam. I didnt know what it was, but I figured if it just came in from Amsterdam and he was a hippie he was offering me some hashish, and I said, no thank you, I dont do drugs. And he doubled over laughing and he said, man, Gouda is how they say Gouda in Amsterdam. So I had just turned down some fine imported Dutch Gouda.

CG: And in another cheese mistake, Elana Lubin wrote us to say that she kept kosher when she was growing up. She had been shielded from the full funkiness of cheese. Her husband though didnt grow up keeping kosher and he loved all those crazy cheese flavors. So they found an upscale kosher restaurant. They were going out to dinner. She was super excited in particular to try blue cheese. They had a cheese plate for the appetizer. She picked it up, she gave it a try, and promptly spit it out. She says its now an ongoing joke - but she still, ten years later, doesnt eat blue cheese.

NT: It is an acquired taste, I hated it as a kid.

CG: I did too but now I love it. Anyway, lets get back to Europe, where all those cheese on Elanas plate - thats likely where they were developed.First - those folks from the Fertile Crescent spread out . So now theyre lactose tolerant, theyre moving to Europe, and what they find there is the perfect environment for cheese-making. Or, I guess I should say, the perfect environments. Take Emmental, since you mentioned it. What some of our listeners may know of as Swiss cheese. Its a little harder, its kind of rubbery and it has holes.

NT: And its got a kind of nutty flavor.

CG: And whats interesting is, so Paul explained this to me: that unique style of cheese developed in the Alps for very specific reasons. The first thing to know is that theyre far from the ocean and they have almost no salt. And salt is crucial to cheese-making.

PK: These cheeses as a practical matter had to be big. It's much easier to transport under difficult conditions like going down a mountain and eventually going across the valleys and mountain passes to distant markets. It's much easier to transport a few large cheeses rather than many small cheeses. There's pressure on the cheese-makers to make bigger cheeses.

CG: Its funny. The limitations of the mountain actually made it hard to make cheese theres the salt thing. And theres the fact that Alpine milk typically has lower levels of lactic acid bacteria. And like Paul says, practically, they had to make larger cheeses. It was a challenge to squeeze out enough of the whey to end up with a good, dry, long lasting cheese. So cheese-makers in the region came up with some clever work-arounds. They invented new curd-cutting tools. They cooked the cheese at higher temperatures. They even build cheese presses to squeeze out the whey. And so all of those techniques end up inadvertently favoring a particular bacteria called Propionibacteria. And they are the ones that produce the carbon dioxide that creates those holes as well as that nutty flavor.

NT: And then meanwhile, in northwestern France, youre not on a mountain. Its cooler, its more humid, and theres plenty of salt. So you get a completely different style of cheese that develop, in response to those conditions.

PK: That creates a microflora naturally present in the milk and the environments that the cheese-makers were surrounded by and had to deal with. And so when you look at the basic technology of Camembert, Brie, or washed rind cheeses Muenster or Limburger. The strong pungent yellowish oranges cheeses.

NT: That sounds like another cheese we tasted with Heather - Saint Nectaire.

HP: So this is a very pungent cheese is a raw milk cheese. It's's a washed rind cheese so as it's aging the outside it is rubbed with a brine solution that contains a lot of salt but it's also microbially rich - Brevibacteria linens are added to it

CG: linens

HP: B.linens, that's the name of the microbe

CG: Mmmm, it's really earthy:

NT: Barnyard in a really good way

CG: Exactly, in a really good way, Im a big fan of barnyard in cheese.(LAUGHTER)

HP: That's in part from being made from raw milk as well. There's a lot going on in the cheese. 10 to the 10 microorganisms

CG: In each bite, that is a crazy idea! (LAUGH)

NT: 10 to the 10! That is 10 billion microbes per bite. Thats more microbes than there are people on Earth!

HP: But theyre smaller!LAUGHTER

CG: The microbes are smaller than the people, yes.

HP: Yes.

CG: And we can eat them.

HP: Yes we can. We do all the time, whether we know it or not.

CG: And were back to microbes again! We havent brought them up for a little while, but we couldnt stay away for ever! Everything seems to lead back to microbes here at Gastropod.

NT: So while we were making this episode, I met a guy who loves microbes even more than we do. He literally has fungal crushes. That sounds disgusting, its not.

CG: It does sound a little gross.

NT: His name is Ben Wolfe and hes a scientist who has just started his own cheese microbiology lab, at Tufts University. I visited with him and we spent an hour just literally gazing at petri dishes filled with cheese microbes. They look like photographs of galaxies and star systems all these swirls of pink and yellow and tiny pinpricks of white and puffballs of grey. Unbelievable.

NT: These are pretty.

BW: Yeah. So this plate is where we're starting to explore the natural history of some of the fungi that grow on certain cheeses. So on this column right here, actually all the way over here, we have the mold scapulariopsis, which is just a wonderful name for a mold that is very Mary Poppinsesque.

NT: So were going to come back to Ben and his lab full of stinky, fuzzy, Mary Poppins molds and yeasts and bacteria later on in the show. But I wanted to introduce him now. Because the science of microbes has a lot to do with this idea of terroir. Paul was talking about this idea that cheeses are kind of an expression of the place where they were developed, the Swiss holey cheeses and the French washed rind cheeses. But as we just heard - and as well dive into more with Ben later - it really has to do with the microbes.

CG: And you know, Paul and I had another interesting conversation about this topic, too. The flavor and texture of cheese is an expression of place, yes. Or, maybe, place-based microbes. But today, its actually a cultural and political issue. Its about what we call the cheese.

PK: The plethora of cheese that developed all over Europe because of these microenvironments and the unique conditions those cheeses over the centuries were given names. Often directly attached to the place that they originated. So the name of the cheese and the place and the development of the cheese are intertwined in the mind of Europeans. That concept of what the French call terroir, that the place and the environment shapes the people and their practices that in turn shape the products that they produce like cheeses. That those cheeses, those products are unique they cannot be duplicated anywhere else in the world. Because you dont have that combination of unique characteristics. The terroir is unique and therefore the cheese is unique. And the name thats given is unique and cannot be separated from the place and the cheese.

CG: Paul said thats the European idea, anyway. And now theres this whole legal structure in place. Its called Protected Designation of Origin, or PDO. It started in France as a way to protect the names of wines from certain regions. Like, for instance, champagne only can come from the Champagne region of France. And now its a whole European Union program. It applies to cheese and even tomatoes and lentils. But heres the problem - PK: Of course Europeans didn't stay in Europe. They moved and emigrated all over the world. And of course America became a magnet for many immigrants and they brought with them their traditional cheese-making.

NT: So all of those immigrants started making cheddar and asiago and brie and gruyere in the United States. Exactly the same way they would have back at home in England and Italy and France and Switzerland, wherever. And so they used the same names. So you have a situation where people in Vermont are making cheddar is the traditional way, but they are doing it thousands of miles from the village of Cheddar, in Somerset. And sure, Cheddar cheese originally developed because of the environment and the conditions in Somerset, but its still the same cheese when you make it the same way in Vermont right?

CG: This whole issue is actually part of ongoing highly sensitive trade discussions. Today those PDO names are only restrictive in Europe, and some cheeses are considered just generic categories, like mozzarella. But Europe wants the names to be restrictive around the world - that is part of these trade arguments. Theres a great example in Pauls book - if the European Union gets its way, all American cheddars would have to be renamed. And he says, you know, maybe a cheese in Vermont would be called something like Vermont Delight.

NT: So this is where we get back to microbes and Ben. A lot of the flavor of cheese not the ricotta-style ones, but the rennet coagulated and aged ones like St. Nectaire the flavor is coming from a whole community of microbes. Some are in the curd, and lots more are on the outside, on the rind. And each different community of microbes is basically what gives each type of cheese its particular flavor and texture.

CG: Like the Swiss cheese and that Propionibacteria.

NT: Precisely. And, as it turns out, a lot of what cheese-makers are doing with all their caves and their washes and their brining what they are actually is setting up the conditions for that particular ecosystem of microbes to develop the right way to make the cheese taste like itself. So Ben spends all day every day looking at these cheese rinds.

BW: In many ways, rind is the structure that people use historically in cheese-making as a way to help preserve the cheese. So you would make cheese through fermentation and then you needed some surface, something to grow or exist on the outside to keep it from being damaged and to make it easy to transport. So people just let these rinds develop.

NT: In a sort of carpet-like structure, almost, right?

BW: We call them biofilms. We call them a biofilm because its a layer, at the surface of the structure that comes together, almost like a small city of microbes, but they glue themselves together they produce substances that allow them to colonize that surface and stick themselves together. So yeah, a carpet is a great way of describing it.

NT: So in July 2014, he wrote a paper with a colleague, Rachel Dutton at Harvard. They surveyed 137 different cheeses from all over Europe and the United States. They wanted to see what microbes were where.

BW: The idea for all this work came from Rachel Dutton. So she started this lab at Harvard. And what we wanted to do is go out and understand: what is the diversity of microbes on cheese rinds? It hadnt been done before in large part because people had been studying their cheese individually. So a producer in northern Italy or a producer in the middle of France would work with a scientist to culture their cheese and they would identify things and have a list. But they wouldnt ever do this in a large systematic and thorough way. And they also would never use the approaches that we use, which were DNA sequencing approaches. So we went out just like people sequence the DNA at crime scenes or sequence the DNA living inside your gut, we decided to do that for cheese, using the same exact techniques. And we did it at a much larger scale. So instead of doing a few cheeses, we did 137 different cheeses made in Europe and North America.So we can, in one broad brushstroke understand the diversity of microbes that is out there.

NT: Once Ben and Rachel had all their samples together, they took them back to the lab and scraped off a little bit of the rind of each one and then they extracted the DNA.

BW: And then once we have that DNA, we can sequence it using all these great new DNA sequencers that people have developed for the human microbiome project or the human genome project, to then decode all the different critters that are there.So what we found is that what the cheese-makers are doing, they are creating environments, particular environments, with certain moistures or certain acidity is or certain salt concentrations. And if they do that, they are selecting from essentially a global pool of microbes. So either microbes that are coming in on the sea salt, microbes that are in the raw milk that theyre using to make their cheeses, or microbes that they even buy as cultures.And if they create the right environment essentially if they build it, the microbes will come. So you end up selecting for this very particular type of microbe, microbial community. So you can make a cheese in California, you can make a very similar cheese in Vermont, and try to make that same cheese in France, and theyll have almost the exact same composition of microbes in the community.

CG: Wait. So does that meant that this PDO thing that Paul and I were talking about is total bullshit. Or maybe not exactly bullshit but maybe just a historical and political thing and not a difference thats actually based in science? I mean, if they are making it the same way, and it has the same microbes that give the cheeses the same flavors.

NT: Hold up. I asked Ben if he had killed the whole idea of terroir, and he said not necessarily.

BW: So at this broad scale we can see that the communities look similar. But were talking about you know walking into essentially an oak forest. So if you walk into an oak forest in California, you walk into an Oak Forest in Vermont, and you walk into an oak forest in France, they would look pretty similar. They would have oak trees, there would probably be some rodents running around in each of these eating the acorns, there is probably some herbaceous plants in the understory. But if you look more carefully, youll notice that the species of oaks are different, youll notice that the rodents are different.So when you walk around those forests, you will notice that there are some subtle nuances that reflect that particular place. And that is what we weren't able to capture in that particular study. So we were not capturing strain level variation.

NT: So after Ben and Rachel did this study which seemed to show that the microbes were basically the same in a Vermont cheddar or and English cheddar, he wanted to go back and see if his suspicions were correct. Do different strains of the same species behave differently? So I mean if a Vermont microbe and an English microbe, even if they are the same species, are they different enough to give a different flavor to give a taste that somehow reflects place?

CG: Has he done that study? What has he found?

NT: Its happening right now! This dear listeners is the most cutting edge, breaking news in cheese science!

CG: Only from Gastropod.

NT: Right now, in a very smelly lab at Tufts University, Ben is studying exactly this. He got cheeses from nine different places Oregon, Maine, France, Spain and so on and isolated the same species of bacteria from each. Then he tried to reconstruct the rinds using strains from different places.

CG: Got it. So based on this study design, the idea is that if the strain doesnt matter, then he should be able to build an Oregon cheese rind using the exact same species, but one that just happens to come from Spain, right?

NT: Right, its like cheese as Lego approach. Except heres the thing its not. Ben is finding that even though these microbes are the same species, these different strains do not act the same way at all. The rinds hes recreating in the lab look different, they smell different, and they taste different.

CG: So basically - there IS actually a microbial terroir.

NT: Exactly. And his next step is to figure out why!

CG: Shhh, dont tell the Europeans. Europeans who are listening, pretend you didnt hear that, I dont want to call my cheese Vermont Delight.

NT: Of course, part of the issue is that Europeans are snobby about American cheese. Because when they think of cheese and America, they are picturing something really, really bad.

CG: Here, let me open up this Velveeta.

HP: (LAUGHS) Do we have to? They won't know! It's radio!(Laughter)

HP: Velveeta is a cheese that is made from the little bits and pieces of natural cheese that are industrially made that are sort of waste products byproduct. And then they get melted down, coagulants are added to it, fillers are added to it, coloring is added to it. And this slurry this cheese slurry, that does have some natural cheese in it somewhere is melted and molded in blocks.

CG: So I love the this image of this huge cheese slurry with all these bits of leftover cheeses.

HP: But there is some real cheese in there somewhere!


CG: Nicky, Is your American orange or yellow

NT: Orange.

CG: Mine is a kind of a pale yellow deli cheese.

NT: Oh, no, mine is definitely orange. Which I think, right, Heather, thats not from the cheese itself, that's annatto - the coloring of vegetable dye that's added.

HP: That's right the orange color comes from the annatto seed which is a plant.

NT: Thats not part of the flavor, its for color?

HP: So it's interesting that goes back to well if you think of American cheddar think of the New York State cheddar and the Wisconsin cheddar. This is one of our most durable cheese traditions. On the East Coast cheddar is not colored, its yellow. And Wisconsin its orange. And that goes back to the 19th century.Cheese-makers originally colored their cheeses to hide evidence of seasonal variation. Which is kind of ironic considering how beloved seasonal variation is these days with artisanal cheeses and it's all been upheld in terms of terroir. But in the 19th century when cheese-making moved from farmhouses to factory production and they were pulling milk for multiple farms and distributing it to a wider network, because the cheese was being traded at greater distances they were trying to standardize the product. One way of standardizing the product was to color the milk so that the spring milk and the winter milk and the summer milk, which had different degrees of beta-carotene and other natural colors based on the animals were eating, whether they were on the fresh grass or dried hay. That you couldnt tell the difference by looking at the cheese which season it was from. And that just became tradition to keep the orange color and Wisconsin.

CG: Wow, I had no idea. And so that's why we now have orange Velveeta andAmerican cheese.

HP: That's right because orange came to designate quality cheese.

CG: I talked to Paul about the origins of the first factory cheeses. And just like Heathers saying that orange means better quality- strangely, its the same thing with factory cheeses. They were trying to optimize cheese.

PK: It really goes back to the scientific revolution the Enlightenment in the 1700s when science began to come into its own and the application of science to practical industries like agriculture. So in England where this really started with sort of the gentleman scientist, the aristocratic folks who had time on their hands and had lands and had an interest in agriculture began to really try to systemetize the cheese-making process in England. Which up to that point had been really secretive and very much an art carried on by the women, the dairy maids and dairy mistresses who handed down that secret knowledge generation to generation, and that had been going on for 1500 years.

CG: And then in the US, you get the supersizing of cheese. There are bigger vats and machines. People move west and theres more land. And that means theres more milk. Everything becomes bigger - and, actually, in some ways, it gets becomes better.

PK: In the early years one of the great advantages of the factory was actually improved quality at least from the buyer's standpoint. It was easier to control a system in a factory with one set of conditions. And one head cheese maker instead of the same amount of cheese being produced at five or 10 different farms with different sets of conditions. So from a quality standpoint if you read period literature the factory was viewed as a great step forward in quality.


NT: And you know whats so interesting is that in some ways, the American slice the iconic Kraft single that represents the logic of cheese taken to its ultimate extreme.

CG: I dont think I like the sound of that -

NT: I fully agree, but if you think about it, the point of cheese was to make milk portable and long-lasting. And James Krafts innovation was to realize that if you melted and boiled cheddar up for 15 minutes and then reformed it into blocks and slices, you made it last even longer and it doesnt melt until you want it to. Its even longer lasting and more portable, in other words, just like cheese is supposed to be.

CG: But you kill all the microbes that gave it all that flavor! And its so standardized that it kind of tastes like nothing. Its just like fat and salt. Though, as Heather pointed out, thats kind of the point. You dont eat it by itself. You put it on sandwiches.

NT: For decades, this kind of block cheese ruled America. In a way, it still does, if you go by sheer volume. Think of all the deli sandwiches and burgers and nachos and pizza cheese

CG: But thank the cheese gods - the traditional diversity of microbially rich, flavorful, distinctive cheeses - that never died out in Europe. And, again, thank you cheese gods - that tradition got rediscovered here in the US in the 1970s and 80s.

PK: Thats a whole new and somewhat unexpected development towards the end of the 20th century that just blossomed and created a whole second track or tier of cheese-making that harkens back to an earlier time. But at the same time that has really benefited from and taken advantage of some of the science and understanding to bring to the table traditional cheese-making but to do so in a way that really can be controlled. In the sense that it's much easier to produce really great consistent quality, traditional cheese. So the modern artisanal cheese movement is the best of both the old and the new it combines the best of both worlds.

NT: In a way, cheese is also part of this much larger story about food and hygiene in the 20th century. At the start of the 20th century you have Louis Pasteur and germ theory and we start trying to make our food system hygienic and scientific. And we spend most of the 20th century getting rid of the microbes.

CG: And, as usual, we went too far. But, more recently, there is a growing awareness that not all microbes are bad.

BW: So generally we think of molds and bacteria as bad things. They wreak havoc, they grow on our toes, they destroy our bread, they make people sick they can do that. And so we often have regarded the microbial world as this pest, as this bad thing. But in fact when you look at a wheel of Camembert, when you taste and experience a wheel of Camembert, that is microbes doing that. Making that thing delicious.

NT: And then what Ben is trying to do is understand how! How those microbes interact to make flavor.

CG: Plus of course now we know that eating microbes in our food is actually *good* for us.

NT: Absolutely, which makes cheese a heath food in my book.

CG: I like that idea.

NT: And it might surprise our listeners, but studying cheese is the perfect model for studying microbes in other systems.

BW: So there is a big interest right now in understanding how communities of microbes assemble. So just like putting a car together, there are certain principles for how you put the pieces of the car together, there's a certain order to how you do it, there are certain things that need to fit together in the right place at the right time. And we think that also happens in microbial communities. We think thats happening in the soil, out in the ocean and in our own bodies. But we don't understand what those principles of community assembly are. In large part because most microbial communities are so complex. So there are thousands of species living together, and you can't grow most of them.So what cheese offers is the ability to develop very basic essentially design principles of how these things come together and do what they do. So we can now dissects them in the lab, they are very simple, we can grow all of them and put them back together and learn those principles in the process.

CG: So how does Ben study microbial relationships in cheese?! Does he stick chunks of cheddar under a microscope?

NT: Kind of actually. What he does is he makes something called in vitro cheeses using this super high end cheese curd from Jasper Hill in Vermont. Only the best for his bacteria.

BW: And we get that cheese curd and we freeze-dry it and grind it up and put it into agar in a petri dish, so it looks like a standard petri dish except it also looks like it has cheese inside of it.

NT: And then its like a cage fight: he puts in whichever two fungi or bacteria he wants to see interacting, and lets them go for it. So, remember that fungus he described as being like Mary Poppins? Under a microscope its got this adorable resemblance to a person holding up an umbrella or a balloon or something. Its called scapulariopsis.

BW: In the middle we have a fungus, the same one, scapulariopsis. But it's growing with another fungus named chrysosporium, which you can see growing by itself all the way over here. And one thing we're trying to figure out is, we see chrysosporium growing on a lot of cheese rinds, a lot of natural rinds, really late in succession, really late as the cheese is aging.What we think is potentially happening is that it may be a mycoparasite. It may actually eat other fungi.It always grows on the top of other fungi. And even when we grow it in the lab, it seems to sort of nestle up next to neighboring fungal colonies. So what we're trying to do is right at that border between the chrysosporium and the scopulariopsis, we're trying to look for any kinds of signatures of mycoparasitism. So looking for where the little fuzzy hyphae of the one mold could be penetrating into the other mold and essentially sucking away some of the nutrients from the host. NT: Basically, the Mary Poppins is being eaten alive by a white fluffy thing. Or so Ben suspects. So one of the things I didnt realize about cheese before I visited with Ben is that it is not just one happy family of microbes and youre done. Instead, the aging process is this intense negotiating table where different fungi and bacteria interact in succession. One may take over from the other, one may set the stage for the other to colonize. And that whole progression over time is what makes the flavor.

CG: But I have a question. In the example you gave there are only two microbes interacting. And arent there - I dont even know how many - but arent there a lot of different types of microbes that may be interacting at one time?

NT: Exactly, dozens and dozens on every cheese. But you have to start somewhere, Cynthia. We just dont know the rules for how those microbes interact with each other. We dont even know how they know the other guys are even there! So Ben is going one relationship at a time, to figure out the ground rules and build up a picture of how the ecosystem works from there.

CG: But we shouldnt make it sound like he doesnt know anything yet - I loved it when you told me that hes become something of a cheese doctor for artisanal cheese-maker.

BW: There isn't a great resource out there for people to understand when their products don't go in the right direction that they want them to. So what we have done is developed some of the knowledge, gone out sequenced what's out there, and we understand the diversity of microbes that you expect to find. So we can then provide this knowledge to help cheese-makers understand, when things don't go right, what can they do? When they have an invasive blue mold, what is it? Where is it potentially coming from?

NT: Its funny, he gets sent Franken-cheeses in the mail all the time. He just emailed me a photo of a bright purple rind on a cheese totally terrifying. Hes managed to identified the two bacteria that are interacting to make the color and help the cheese-maker tone it down. CG: Strangely one of our listeners sent us a photo of just such a Franken-cheese! Its a shot Etta Divine took in France - she called herself Moldy in Avignon in the email. She was pretty turned off by these bizarre oozing brown cheeses she saw in the market. Heres her theory, she had three ideas. One was that you could buy them to infect your own milk to make cheese. Two, you could mix them in with other cheeses for an extra strong cheesy flavor. Or three, she said, maybe the cheese monger was just fucking with the buyers.

NT: I was leaning to option three there, but I sent the photo to Ben, our cheese doctor extraordinaire .

CG: And?

NT: He said that he too has seen equally disgusting cheeses from France. They were so brown and dusty he said he thought they were bread or bagels. But he asked, and they are in fact intended to be eaten. Although not by him, he didnt actually try them, despite being a microbe lover.

CG: A little too much, even for Ben.

NT: I think you have to be born French. So the cool thing is that all of this research is helping cheese makers improve their product, and its helping microbiologists understand how microbial ecology works. And that is great. But it is also generating new ideas for the future of cheese. After all, there are a lot of other microbes out there that make tasty foods that dont currently get used in cheese making.

NT: I mean, I know the primary goal of your research is to understand the microbe interactions and less what the flavor implications might be, or even the human health implications but are we talking about a miso flavored cheese, here? BW: Absolutely. The end goal could be that. But along the way we are going to learn a lot of really cool basic microbiology. And we can learn more about the evolution of these microbes. And hopefully they will produce a new flavored cheese. NT: Miso flavored cheese it's like two of my favorite BW: This amazing yeast, which grows really abundantly in soy sauce fermentation and miso fermentation and produces that caramelly, that classic sort of dark, rich flavor of those foods. And we are trying to understand if we can get that to jump over to cheese yeah. NT: My mouth is watering!

CG: Mmmm. That sounds amazing. Those are two things Im completely obsessed with.

NT: Form an orderly queue, Cynthia. Im first! So, we thought we had everything figured out. And then we heard from Doug in Perth.

DOUG: Loving the show. The only cheese story I maintain relates to butter. I maintain butter is effectively cheese with a low melting point. So its okay to eat it in a similar way. My fifteen month old daughter agrees. Shes a demon for butter and cheese. Which leads me to wonder - how is cheese defined? And does butter really count? Is there a grey area?

CG: Back to Heather! We put this question to her, while we were trying to figure out what cheese actually was. And she was clear. Butter is not cheese.

NT: Thank god.

CG: First, because its all fat - all cream, not milk. Second, because its not coagulated.

HP: And that process is really central to what makes cheese cheese. It can happen in many different way. But its the separation of curds from whey and that doesn't happen with butter.

NT: Dont let that stop you, though, Doug. Butter is good for you again these days, I hear. But have it with some cheese!

CG: And, in fact, we have the combined our experts to arrive at the ultimate cheese plate.

NT: For people listening at home, if they want to put together a cheese plate that is, shows interesting microbial associations and communities, and then show off to their friends about their newfound knowledge, what would be on this cheese plate?

BW: So I think many people break down the world of cheese by milk type, and that is not the way to go if you are trying to impress your friends about microbial diversity. You should go with the rind type. So the three main types of rinds that we talk about in our paper and that I like to think about are natural rind cheeses, washed rind cheeses, and bloomy rind cheeses.So an example of a bloomy rind cheese would be something like Camembert. Very classic, those white fluffy delicious cheeses that are very creamy, often quite young. And those are very manicured lawns of microbes. So there's a been heavily inoculated and they have this very controlled garden of microbes on them.The washed rind cheeses are those sort of funkier, stinkier cheeses that are washed repeatedly with some kind of brine solution, and those are more yeasty, they have a lot of bacterial diversity in them, the bacteria are producing a lot of these flavor compounds that we smell and taste. And those are more like a very disturbed like the ocean coast, where the water is coming in and repeatedly disturbing that ecosystem and selecting for microbes that can tolerate those disturbances. And so you will get a lot of unique microbes that can only deal with a heavily disturbed environment.

NT: So thats like the Saint Nectaire we tried with Heather.

CG: She also recommended Twig Farm, which is a Vermont cheese. And Taleggio is a classic, commonly available washed rind cheese.

BW: And the natural rind cheeses are essentially like an old growth forest it is nature thats just run its own course, the cheese maker doesn't intervene very much, and you will get a lot of these really craggly old molds and yeasts and bacteria that are sort of this very old and very mature type of ecosystem at a microbial scale. And I love those kinds of cheeses, because they look like lichen-covered rock. They are very beautiful.

NT: A lot of cloth-bound cheddars are natural rind cheese. And if youre up for the challenge and think you can handle it, a traditional Stilton is also a natural rind cheese.

CG: So we have got your next cheese board settled. You could put out ricotta too, or maybe some chevre, to represent that older style of acid-heat coagulated cheese from 9000 years ago. And were not going to stop you from putting out some Velveeta, but I cant say I recommend it.


LISTENER: My names Tasha, Im a listener from the Boston area. Im obsessed with Gastropod. When I found out you guys were doing an episode on cheese I got really excited. Cheese is probably my favorite food. I eat it on almost everything. I pretty much eat it every day. I think Id say my favorite kind of cheese, like an Arabic braided string cheese, the flavor is just amazing. And then my other favorite cheese is Saint George cheese, its from Portugal. When I was a kid my dad used to love it, but I hated it, I used to call it smelly feet cheese. Smells pretty nasty, but it tastes heavenly. So thats my little bit about cheese, I love it, its the bomb, cheese is the best thing ever.


NT: Thats it for this episode. The future of cheese is golden.

CG: The future of your cheese plate is even better. A huge thanks to our guests - Paul Kindstedt at the University of Vermont. He wrote the book Cheese and Culture. And to Heather Paxson, MIT anthropologist, she has a book called The Life of Cheese. Thanks for tasting all those great cheeses with us.

NT: And thanks also Benjamin Wolfe at Tufts University. We have lots of his amazingly beautiful cheese microbe photos online at Not kidding, they look like faraway galaxies. We also have links to the paper he published with Rachel Dutton on cheese rind microbiology.

CG: And thanks to you, listeners, for sharing so many cheese stories with us.

NT: As always, we have all sorts of good stuff online photos, videos, links, and stories we couldnt fit in the episode. Visit us there at, where you can also sign up for our emails, binge listen to old episodes, and get in touch with us yourselves.

CG: If you or your company or nonprofit are interested in sponsoring a future episode, please email us at contact at

NT: If youre a fan, you can help us out by telling your friends and family how much you love us. You can also write a glowing review on iTunes. And you can like us on Facebook or follow us on Twitter at gastropodcast.

CG: Thanks for listening -

NT: Til next time!