TRANSCRIPT Gum’s the Word

This is a transcript of the Gastropod episode, Gum’s the Word: A Sticky Story, first released on March 22, 2022. It is provided as a courtesy and may contain errors.




GRABER: Oh, it’s horrible. How soon can I spit it out?

TWILLEY: I can’t get enough of it out of my mouth.

GRABER: I have a little bit stuck in my teeth!

TWILLEY: Okay, it’s dry, it’s crunchy, and it tastes like, I don’t even know.

GRABER: It tastes like really bad incense.



TWILLEY: Listen folks, it is not all fun and games here at Gastropod. Which is what you’re listening to, by the way. I’m Nicola Twilley.

GRABER: And I’m Cynthia Graber, and like Nicky said, this is Gastropod, the podcast that looks at food through the lens of science and history. Sometimes, you know, we stretch our definition of what food is — to things that you just chew on.

TWILLEY: Point of order, Cynthia: chewing gum is food at least according to the Federal Food and Drug Administration, aka the FDA.

GRABER: Great, so it really is a perfect fit. Food it is.

TWILLEY: But you know, not food you swallow. Although, will it kill you if you do?

GRABER: That’s an easy answer — you will not die from swallowing chewing gum. But other questions about gum are a little stickier. Like what do a Mexican president, the battle of the Alamo, and Staten Island have to do with the invention of modern chewing gum?

TWILLEY: We’ve got that story, alongside many more topics that you can really sink your teeth into, such as: what on Earth did people chew before the advent of Juicy Fruit.

GRABER: And even more basic — what the hell is gum, anyway? What ingredients in it allow you to keep chewing and chewing and even blow bubbles and the damn thing never disintegrates? What is going on?

TWILLEY: All that plus Emily Post’s great great grand-daughter lays down the law on the thorny subject of chewing gum etiquette.

GRABER: This episode is sponsored in part by the Alfred P Sloan Foundation for the public understanding of science, technology and economics. Gastropod is part of the Vox Media Podcast Network in partnership with Eater.


JENNIFER MATHEWS: So it’s interesting because apparently we have a need to chew. And when we look archaeologically, we find pieces of chewing gum dating to like 6, 7, 8, 9, 10,000 years ago.

TWILLEY: Jennifer Mathews is a professor of anthropology at Trinity University in Texas. She is also the author of the book Chicle: The Chewing Gum Of The Americas From Ancient Maya To William Wrigley. And she told us that humans around the world found a wide range of things to chew on in the deep and distant past.

MATHEWS: Among the ancient Greeks, for example, they were eating mastic from the mastic tree, which is where the term mastication likely comes from.

MATHEWS: In India, there was a prickly shrub that they would get something called lama from that they would chew on.

MATHEWS: In Europe, it starts with Birch tar. They would often put honey on it to make it a little sweeter.

GRABER: Nicky and I grew up chewing the type of gum you buy at the store, not tar you’d collected from trees, so we really wanted to know what this original chewing gum might have felt and tasted like. We started with frankincense.

TWILLEY: I know, you’re thinking frankincense? Did one of the three wise men really bring baby Jesus chewing gum? But yes, indeed, frankincense is the fragrant sticky resin from a particular type of tree that grows around the horn of Africa and the Arabian peninsula, And throughout history people have not only burned it as incense but also chewed it like gum. So we decided to try it ourselves.

GRABER: I have two, one slightly larger and one little piece here. They smell VERY strongly, just what you would expect from frankincense, wow.

GRABER: And, as you might remember from the start of the show, frankincense was absolutely truly revoltingly disgusting. We took it out of our mouths pretty much as quickly as we could.

GRABER: Eww. Blegh!

TWILLEY: Let’s chew something else quickly. Let’s chew some mastic?

GRABER: Mastic looks almost the same, a little clearer than the frankincense.

TWILLEY: Whew. This smells intense.

GRABER: Yes it does.


GRABER: The smell is more pleasant to me than the frankincense was.

TWILLEY: It’s very… particular.

GRABER: (Laughs) It is. It’s very medicinal smelling. Okay are we going to try this?

TWILLEY: Even though I don’t want to! (laughs)

GRABER: I’m scared, I don’t really want to either.



GRABER: Oh, it’s very noisy.

TWILLEY: Also crunchy and dry. It’s chewable, it hasn’t totally broken apart. But you would have to pay me to chew this.

GRABER: It forms a wad, as opposed to the frankincense which was not forming a wad, which sounds all very appealing.

TWILLEY: It’s actually – very, umm hard. It’s like a workout, a jaw workout. It’s tough.

GRABER: Yeah, it totally is.

TWILLEY: It’s intense.

GRABER: Like this I could imagine chewing on. It feels kind of like medicine. Not like a kid would do it for fun, but who knows what they did for fun back then!

TWILLEY: Limited things. This is really hard work. But it’s not unpleasant, I just… Especially now it’s formed the chewable mass so to speak. (laugh)

GRABER: So that’s frankincense and mastic, mastic was the clear winner there, as tough as it was to chew. Jennifer mentioned people chewed birch tar in ancient Europe, but we couldn’t get a hold of birch tar to taste.

THEIS JENSEN: From what I’ve heard, other people say about the pitch is that it was, it was fairly potent in a way. And you could get a little bit like a stinging sensation in your mouth.

TWILLEY: This is Theis Jensen, he’s an archaeologist at the University of Copenhagen in Denmark. And a few years ago, he was on a dig at a super cool site buried deep in the mud on an island in Southern Denmark.

JENSEN: It is basically kind of like a preserved Stone Age landscape just down there, two to three meters below modern day surface.

GRABER: Don’t worry, this does actually have to do with gum.

JENSEN: I was in working in Sweden in 2009 and one of our colleagues came over with like this small piece and said like, look, guys, you need to look out for these small pieces. They are chewed birch pitch. We all like, whoa, what is that? Never seen it before. And it was indeed very difficult to see, but once we all saw it, then it was quite easy to actually find them.

TWILLEY: Like Jennifer told us, bits of chewed birch tar have been found going back ten thousand years or so in Europe. But why exactly were people chewing this tar?

GRABER: Theis told us one theory is that people chewed the tar to soften it, because they stuck that softened tar everywhere as a glue — it could plug a hole in a canoe and fix broken pots.

JENSEN: I mean, it was used for everything. It’s used for hafting, it’s used for caulking. It was used for waterproofing. It was used for whatever.

TWILLEY: But Theis said, Neolithic people might also have been chewing birch tar just for the joys and benefits of chewing.

JENSEN: They contain teeth imprints from a milk teeth, like, uh, so it was kids chewing it. It could be for when you’re getting your permannt teeth to get the other ones out. So you have something to chew on and then suddenly your teeth fall out.

GRABER: You know, like an elementary school teething ring type of thing.

JENSEN: It’s also antibacterial. So could be, it’s just for hygiene in a way. And also: I want to just go and chew stuff.

TWILLEY: Theis says that there are actually accounts of Laplanders chewing birch tar for ritualpurposes as recently as the 1800s.

JENSEN: When you had to propose to a girl or something like that, then you would be chewing this and then you would hold it between your teeth and then the girl would come and take it from you and then keep on chewing it and stuff like that.

GRABER: This sounds super romantic. Yum.

TWILLEY: Sharing bodily fluids is what it’s all about, Cynthia.

GRABER: But — speaking of bodily fluids, that’s kind of what Theis was looking for. At the time, Theis was getting his PhD and his professor had strongly suggested that he should find something — anything really — that might have some ancient DNA on it that he could sequence.

TWILLEY: Even though other archaeologists had dug up these lumps of chewed birch tar before, no one had really thought to test it for DNA. Theis’s PhD advisor was very skeptical about the chances of finding anything.

JENSEN: And then it turned out to be incredible. I mean, just one thing was that we found all this human DNA, which is quite astonishing

GRABER: Because there just isn’t a lot of human DNA from that time period. And from the DNA, they could tell that the birch tar had been chewed by a woman. They couldn’t tell exactly how old she was, but they assumed she was young.

JENSEN: Based on the assumption that most of these pieces, they have teeth imprints from kids.

JENSEN: And then of course, we had the data from the phenotypical traits that she had dark skin, dark hair and blue eyes, which was a fairly common trait at this point.

TWILLEY: What was also interesting is that they figured out using carbon dating that the gum was 5,700 years old.

JENSEN: So that meant the pitch was extracted and obviously chewed, 300 years into the Neolithic. So it was like the period where you go from farming and you have domesticates and whatnot.

GRABER: At this point, people who lived in the region had started settling down and farming, but this young woman wasn’t a farmer, she wasn’t one of them.

JENSEN: That was the most astonishing thing I think, was that this person was basically a hundred percent hunter gatherer.

TWILLEY: Theis already suspected this, based on the food remains found at the site, but, thanks to the magic of DNA, he could tell this young lady had been eating exclusively foraged foods, rather than domesticated crops, right before she popped a wad of birch tar gum in her mouth.

JENSEN: There’s a very high chance that she ate two ducks. And it’s not really surprising in a way, but it was, it was, it was super cool that we could tell it, because we did find a lot of duck bones and, and, uh, other waterfowl and birds and stuff like that from the site.

JENSEN: So I was, that was really cool that we could say that she did eat it.

JENSEN: And then also hazelnuts.

JENSEN: So, eel, nuts and uh, and ducks.

GRABER: Sounds like a great dinner to me. And then Theis and his colleagues even sequenced the microbes that were living in her mouth at the time.


GRABER: Her oral microbiome looked like a pretty standard oral microbiome today. Which was also interesting. And now, scientists are looking more closely at these tiny chewed pieces they’d previously been seeing as just kind of a curiosity. It’s a source of genetic information that archaeologists had been pretty much ignoring.

GRABER: And in case you were wondering whether the gum you spat out yesterday solidified and saved bits of your DNA, well, Theis has news for you.

JENSEN: Definitely. I mean, I don’t know how long it would preserve it, if you, if you just spat it out on the ground, on the street. But there are various forensic papers where they extract DNA from chewing gum. So that’s definitely doable.

JENSEN: So it’s not to get paranoid, but I mean, we’re leaving our DNA everywhere we walk. You know, you just need a couple of molecules in there. Then it’s enough to say a lot about you.

TWILLEY: Or, in the case of Theis’s research, it’s enough to say a lot about some previously pretty mysterious Stone Age ancestors!

GRABER: So in northern Europe, the gum of choice was birch resin or birch tar. Here in North America, a different tree supplied the local chewing needs, and that was spruce. Which we did get to try.

TWILLEY: So this is a darker color and bigger pieces. I mean all of these are very raw looking, let’s say.

GRABER: Like things that you’d find on the ground that people would say, don’t eat that.

GRABER: This looks like a piece of dirt, or like a piece of tree bark.

TWILLEY: Yeah this looks like actual resin that you would peel off a pine tree.

GRABER: Totally.

TWILLEY: That’s exactly what it is, and exactly what it looks like. (Laugh)

GRABER: Not a strong smell.

TWILLEY: I hate the way they all crunch when you put them in your mouth. It’s really disgusting.

GRABER: And you don’t feel like it’s going to turn into anything chewable.

GRABER: Ew. Ewww! I can’t do it! I can’t even do it.


GRABER: Oh my god that’s so gross! AHHHHHHHH. That’s disgusting!!

TWILLEY: I can’t get it out of my mouth.

GRABER: Sorry!

TWILLEY: How did people chew that?

GRABER: Oh my god I still have some in my teeth too. Ughh!



TWILLEY: That was bitter, medicinal, disgusting.


TWILLEY: The texture was all wrong.

GRABER: Horrible.

TWILLEY: Worse than frankincense, potentially.

TWILLEY: Sometimes I do not understand these ancestral peoples. What were they thinking?

GRABER: I was relieved to learn from Jennifer that a little further south in what’s now Mexico and Guatemala, they didn’t have to suffer the horrors of spruce resin, they chewed on something called chicle.

TWILLEY: This is another sticky thing from a tree — this time, it’s a tropical evergreen tree called the sapodilla.

MATHEWS: So the sapodilla tree is a tree that’s indigenous in Meso-America. So it’s found primarily in Southern Mexico, into Belize, Guatemala, Honduras, and El Salvador.

MATHEWS: And it’s a tree that is made out of an incredibly hard durable wood. The ancient Maya would use the wood to produce monuments that in some cases are still preserved today. That’s how hard the wood is.

MATHEWS: However, when cut into the wood of the sapodilla tree, it actually bleeds a latex as a kind of natural protection for the tree. So if something cuts into it or if insects bore into it, it is producing this latex as a kind of stop gap so that the tree bark doesn’t become infected.

TWILLEY: So chicle comes from this delightful tree, and humans have been harvesting it for millennia.

MATHEWS: The Maya would cut big slashes into the chicle tree and allow the resin to drop down the side of the bark and then collect it in bags. And they had been doing this for hundreds and hundreds of years.

MATHEWS: And so the, the sapodilla tree is kind of like the giving tree in that it has fruits that bats and monkeys and other insects and animals love to eat.

MATHEWS: It’s got this incredibly durable wood that can be used for all kinds of wood products. And then it’s got this natural latex, that was used by ancient Maya peoples, for fillings, right. To kind of fill in, cavities in your teeth.

MATHEWS: It was used, almost like a, like a rubber on the base of your shoes, or to waterproof canoes and things.

MATHEWS: So it had a whole different array of gifts that come out of this tree.

GRABER: But the chicle? What’s it like to chew it?

MATHEWS: So I’ve literally chewed it straight off of the tree. It’s gray, it’s rubbery. It doesn’t have a lot of flavor. It kind of feels like if you chewed one of those old gray erasers you used to get when you were a kid.

TWILLEY: Sounds great! Which is maybe why the Mayans didn’t typically chew it raw.

MATHEWS: So we do know that they would often cook it down to kind of take out any kind of plants’ remains or insects or things that had gotten, you could kind of clean it by cooking it down and boiling it and almost whipping it like cake batter to fluff it up a little bit.

MATHEWS: Mostly it was unflavored, although they could have added honey, for example, into it, honey was a very common product in the Maya region and sweetened it up a bit.

GRABER: As it turns out, there is a modern version of processed chicle — unlike the other far too natural chewing resins we tried, chicle we could try processed and flavored.

TWILLEY: They look like kibble or bacon treats or something. And really unpleasant like that. (laugh) Deeply…unappealing on a visual level.

GRABER: This is not plain chicle. This is chicle that has been made into chewing gum.

TWILLEY: It’s also got wax and sugar. And, like, flavor.

GRABER: Um hmmm.

TWILLEY: Although now the more I’m chewing it, um – the texture is all wrong.

GRABER: It’s stickier?

TWILLEY: It’s way too sticky.

GRABER: Mm hmm. It’s getting caught in my teeth. And it feels like I can chew it. But it feels like it’s about to dissolve at any moment.

TWILLEY: It feels like it’s going a little stringy, though, if that makes sense.

GRABER: We didn’t love it, though the fact that it was actually flavored with ginger was a huge relief after the frankincense and especially the spruce.

TWILLEY: But weirdly, Jennifer told us that it was spruce gum that was the first commercial chewing gum.

MATHEWS: What would happen is that you would have lumberjacks who were collecting wood to make newspaper pulp, and along the way would also collect the spruce gum.

MATHEWS: So they would make sticks of the, the spruce tree gum, put cornstarch over it and then wrap it in paper. And then they would have these little, illustrated wrappers on the outside.

MATHEWS: And so this became one of the more popular chewing gums, although on a very restricted basis, in 19th century New England.

GRABER: I can say for sure that I would not have bought this. Luckily, by the late 1800s, there was a major advance in the world of chewing gum.

MATHEWS: There was a man by the name of Thomas Adams who came into contact with Antonio Lopez de Santa Anna, who was the president of Mexico over 11 different timeframes, who was in exile, in Staten island, in New York.

MATHEWS: And he was interested in putting a fortune together so that he could make a 12th attempt at being president of Mexico.

TWILLEY: If you’re Texan, here’s your trigger warning: we are about to remember the Alamo. After this break.


GRABER: So before Santa Anna ended up in exile in Staten Island, he had a slightly more illustrious career. He’d resigned as president of Mexico to lead the Mexican army, and they were trying to take back Texas for Mexico.

TWILLEY: And as part of that effort, Santa Anna led his troops in an attack on the Alamo, which was a Spanish mission turned military garrison where the Texan troops were hiding out. And he won that battle. Quite decisively and quite brutally. Santa Anna actually commanded his troops to systematically bayonet all the Texans left in the complex of buildings after they took it over.

GRABER: But because he led such a bloody and cruel strike, other Texans were riled up. They used “remember the Alamo” as a war cry against the Mexicans, and they eventually won their independence.

TWILLEY: Santa Anna’s adventures were not yet over, however. He went back to Mexico as a hero. He lost a leg in something called the Pastry War with France. He became president for the 11th time. And then he got scammed by a random Colombian into spending all his money on going to New York for reasons that are way too complex to get into.

GRABER: But the point is, this former multi multi-term Mexican president and general ended up kind of penniless on Staten Island. But he had brought something unusual with him.

MATHEWS: He had brought a store of chicle from his home in Mexico, in the hopes that he could find an inventor who could turn it into the next kind of rubber.

MATHEWS: He grew up in Veracruz, where there were lots of rubber plantations. And he was well aware of the great fortunes that were being produced in the 19th century. And he thought this could be the next new thing.

TWILLEY: And then, in one of those special moments that changes the course of human history, Santa Anna got in touch with a guy called Thomas Adams, who at the time was selling glass down the street, also on Staten Island.

MATHEWS: So he had always dabbled in inventions. He had done daguerrotype photography in the 19th century, was interested in glass making and was interested in creating things like harnesses for draft animals and things. And so was known around Staten island as a local inventor.

GRABER: Thomas Adams thought Santa Anna’s idea of finding a new source of rubber was a great one, and he set his inventor’s mind to figuring out a way to get chicle to do what rubber did so well, like for bicycle tires and even blimps.

MATHEWS: Well, Thomas Adams spent about a year trying to get the chicle to, to work. And it simply would not process the same way that rubber does.

MATHEWS: And he was about to give up. He had gone into a confectionary store where there was a little girl asking for paraffin wax gum, and he said, wait a minute, I’ve got barrels of this stuff at home.

MATHEWS: And it would make the perfect chewing gum. I mean, people have been chewing it in Mexico for centuries.

MATHEWS: And so he went home and immediately sat down with his sons and said, forget the rubber idea. We’re going to make chewing gum.

MATHEWS: And so they made these very kind of unappealing, little gray rubber balls.

TWILLEY: Unappealing maybe, but when Thomas took these chicle balls to the confectionary store, they sold really fast.

TWILLEY: The bar at the time was exceedingly low — people were chewing spruce gum, which we’ve already established is totally revolting. Or paraffin wax, which also doesn’t sound super appealing. So based on that initial success, Thomas went all in on chicle gum.

MATHEWS: One he starts adding flavor to it. So he adds things like licorice, producing a very popular licorice gum that he ends up selling in vending machines. So if you went into the subway in New York, for example, you could buy chewing gum in the vending machine while you were waiting for your next train.

MATHEWS: He also created a machine at cash registers where if you were supposed to get a penny back of change, instead, they could offer you a penny’s worth of gum, that they would simply slice off and hand to you instead of the gum and instead of the change.

MATHEWS: And, chicle really spread in popularity quite quickly, virtually making fortunes for multiple people in the United States.

GRABER: Alas, Santa Anna was not one of those many future chicle millionaires. He got tired of waiting to see whether chicle could actually make him the fortune he so desperately desired.

MATHEWS: And eventually before any of this happened with chewing gum had returned to Mexico, basically impoverished, and died in Mexico, never making a comeback. And so, had no idea that he had had this massive impact on the chewing gum industry.

TWILLEY: Remember the Alamo indeed. Meanwhile, Adams’ company became one of the biggest gum companies in the world — he renamed it the American Chicle Company and it’s now owned by Cadbury. But you’ll recognize some of its gums, like Dentyne and of course Chiclets.

MALE ANNOUNCER: What’s new in the magic land of chiclets?

GIRL: (singing) In this land of flavor and fun, all the flowers are chewing gum. Just pick a bud and what do you get?

GIRL: Fruit flavors! Chiclets!

GRABER: But Adams wasn’t alone. His chicle was such a hit that other people thought they could get a piece of this new pie – or, you know, new pack of gum.

MATHEWS: So William Wrigley was a character, shall we say, from the time he was a child.

MATHEWS: He grew up often in trouble in school, he got kicked out of school frequently. His father ran a soap company, and as a very young boy at like ten or eleven convinced him that he should be able to work in the company.

MATHEWS: He ended up leaving for New York as a young boy, sleeping on the streets, selling soap, selling newspapers, making a go however he could.

MATHEWS: Eventually as he got a little bit older, he started traveling the country as a soap salesman. And when he would sell the soap, he would offer premiums or gifts that the merchants could receive, if they bought a large enough amount of his father’s soap.

MATHEWS: And so they would offer things like umbrellas or raincoats or cookbooks… or chewing gum.

MATHEWS: And it turned out that chewing gum became one of the most popular premiums that he could offer. And he thought, why am I selling soap when I could be selling chewing gum?

TWILLEY: Wrigley is still a name that is basically synonymous with chewing gum today. And, although he isn’t the father of chewing gum, he did introduce some of its iconic flavors — Juicy Fruit and Double Mint.


WOMEN: (singing) Double fresh, double smooth. Double delicious to chew!

WOMEN: (singing) A double pleasure’s waiting for you – Doublemint Gum!

GRABER: Wrigley became a chewing gum king — he owned an island off California, he owned a baseball team, the Chicago Cubs, who still play at Wrigley Field, his face appeared on postage stamps and the cover of magazines.

MATHEWS: But it was not without its bumps. He made fortunes and lost fortunes.

MATHEWS: His whole endeavor was marketing. He thought you’ve got to get the name out there of your product. And he would buy up entire sets of billboards in the entire town. And sometimes he ended up making an impact and other times he lost his shirt.

MATHEWS: But he just had this attitude that he just needed to get the marketing out there for his product. He once bought up billboards along the new New Jersey turnpikes that went on for almost a hundred miles so that people just continuously saw the marketing for Wrigley’s gum.

MATHEWS: And then at one point he sent four pieces of gum to every person listed in the phone book.

GRABER: As we said, he did end up making a fortune—but once again, he wasn’t alone. Other people invented new flavors and new formats like gumballs, and they made lots of money, too. And then, I never thought of this as something that had to be invented, but it did: bubble gum was invented. You can’t blow a bubble chewing normal chicle.

MATHEWS: So it’s an interesting story. Bubblegum’s invented in 1928 by a guy by the name of Walter Deemer. And Walter Deemer is an accountant, of all things, working for the Fleer brothers chewing gum company.

MATHEWS: I guess he got bored with accounting and at one point decided to make his own invention and he never revealed what the base product was.

MATHEWS: The only thing he would say was that it was a rubbery tree latex that was more elastic and less sticky than chicle.

MATHEWS: And he spent months and months experimenting with this latex until he got it to this nice chewy consistency. And it turned out that the only food coloring color that he had was pink.

GRABER: That’s right, the fact that when I say that something is bubblegum color you know exactly what I mean, that’s just because of the food coloring that one former accountant had lying around.

MATHEWS: He ends up inventing what became known as Double Bubble, which became one of the Fleer brothers major sellers.


MATHEWS: And when they would sell it on the road, salesmen were trained to blow giant bubbles as a way of marketing the product.

TWILLEY: Obviously, bubble gum became a huge hit.

MATHEWS: People fell in love with Double Bubble, and then you had other companies like Bazooka that were coming up with it and they start putting bubble gum in with trading cards, like plane spotting cards or baseball cards, or you name it.

MATHEWS: Bubblegum was in there and it, then it became that people were buying it more for the cards than the bubble gum.

GRABER: Chewing gum, bubblegum, whatever you want to call it, it became a multi million dollar industry, fortunes were made, kids around America were chewing and blowing bubbles —

BACKGROUND SINGERS: Choo’n gum, choo’n gum
Choo’n, choo’n, choo’n gum

TERESA BREWER: (singing) My mom gave me a nickel
To buy a pickle
I didn’t buy a pickle
I bought some choo’n gum

GRABER: And then Wrigley secured gum’s global domination. He talked to some people who were interested in the fact that not only did Americans love gum, but it might help if you didn’t always have a toothbrush around.

MATHEWS: Once he convinced the military to include it in the rations, that was it. Chewing gum became a worldwide phenomenon. Because those soldiers were taking that chewing gum, and not only chewing it in the field, but sharing it with kids everywhere they went.

GRABER: All of this demand meant that the sapodilla trees were getting overexploited. And manufacturers started to look elsewhere.

TWILLEY: Jennifer said that by the 1950s, chicle production was already starting to collapse, and by the 1970s it was almost non-existent.

MATHEWS: Because folks like William Wrigley are looking for synthetic sources of chewing gum that can be more reliably produced.

GRABER: So what were those synthetic sources they found? What is gum actually made of today?

TWILLEY: We figured the best person to answer that question is a chewing gum scientist. You heard that right. His name is Joan Mestres, and he’s worked in the gum world for decades.

JOAN MESTRES: You need gum base. You cannot have a chewing gum without the gum base.

TWILLEY: Next time you look at a packet of gum, at least in the US, you will see that the primary ingredient is indeed this mysterious all-important gum base. But I find personally that I am not really very enlightened by that phrase. What is actually gum base?

MESTRES: Well, gum base is a combination of different ingredients. It is made of rubber. So a polymer that gives you this chewy profile, this chewy characteristic. But then you have resin. Then you have wax. And then you have emulsifiers and a mineral filler that is usually calcium carbonate or talc powder.

MESTRES: So when you combine all these ingredients in a mixer, you mix them at high temperature and then you obtain the gum base.

GRABER: Okay, so rubber is one ingredient, like a food-grade version of a car tire. Then there’s the wax, you know, like a candle. And a resin is just something like those tree tars we tried, but it can also be synthetic, it’s basically something that’s sticky.

MESTRES: So you take a candle, you take a tire, you take a resin, (laugh) you put some calcium carbonate, then more or less, you have a gum base.

TWILLEY: Yum! As it turns out, some natural substances combine these ingredients already — chicle, straight from the tree, is actually made up of about 60 percent resin and 15 percent rubber.

GRABER: You can’t tweak the proportions of resin and rubber in natural chicle. But you can in today’s synthetic gum, by playing with the proportions of the more than 30 allowed gum base ingredients.

MESTRES: If we use more rubber in the formulation, you have something in your mouth that is more rubbery. Well, may sound silly, but itIs like this.

MESTRES: When you use more wax, in the formulation of a gum base, you have something that is more plastic.

MESTRES: So by combining these ingredients, we obtain different chewing profiles, and the different gums that you can find in the market. Some of them are harder, softer.

MESTRES: Some of them blow a very nice bubble. Some others do not blow a bubble at all.

TWILLEY: If you think about it, 30 something different possible ingredients and all their possible combinations adds up to a lot of potential variety in your final gum.

MESTRES: For instance, in Japan, they like soft gum. And I like as well.

MESTRES: In the States for instance, a harder chew is preferred.

MESTRES: And when I see these NBA with all the basketball players chewing gum. And usually sometimes it’s used to relieve stress or with other objectives. But in the States, chewing gums are harder than in other parts of the world.

GRABER: But as critical as the gum base is, it’s actually only about 30 percent of what you’re chewing — the rest is mostly sweetener. And then there’s obviously also some flavor.

TWILLEY: Flavor is the bane of gum manufacturers’ lives because after a few minutes of having a particular flavor in your mouth, your brain just tunes it out, you don’t perceive it anymore. But the flavor is still there.

MESTRES: Yes. There is a very, something very easy you can do. Maybe not that nice but easy to do.

MESTRES: You take this piece of gum out of your mouth. You leave it on the table for one hour. You drink water, you clean your mouth.

MESTRES: And when you put that, that, that piece of gum again, inside your mouth, you will feel that there is still a lot of, a lot of flavor there.

TWILLEY: And I am not going to try this at home.

GRABER: But there is a way around this problem. Gum designers can use fancy encapsulation techniques to put little bursts of flavor in the gum — and they can even make the gum change flavor mid chew.


WILLY WONKA: What you are witnessing, dear friends, is the most enormous miracle of the machine age. The creation of a confectionary giant.


WONKA: Finito!

VERRUCA: That’s all?

WONKA: That’s all? don’t you know what this is?

VIOLET: By gum, it’s gum!

WONKA: Wrong! It’s the most amazing, fabulous, sensational gum in the whole world!

VIOLET: What’s so fab about it?

WONKA: This little piece of gum is a three course dinner.

MESTRES: Well, this is a combination of solubilities.

TWILLEY: Joan knows Mr. Wonka’s secrets. And he spilled them all to us.

MESTRES: If you put a flavor, which is water soluble, you will have this flavor at the beginning immediately because your saliva will dissolve it quickly. And now you combine with other flavor, which is oil soluble, that you will be extracting it later.

MESTRES: And then you can use, as well, micro encapsulated flavors, flavors that come inside particles, inside encapsulated particles let’s say.

MESTRES: And these particles are released only when you break them. So only by your chewing action, is what is going to break these particles.

MESTRES: By combining different types of flavors, with different solubilities, with different technologies, you can obtain this effect of having one flavor more at the beginning and a different flavor more at the end of the chew.

GRABER: Cool technology — but most of us don’t bother with complicated multi flavor gums, there is one flavor that is the absolute winner.

MESTRES: Mint. Clearly. Mint is king. By far, the most-used flavoring chewing gum is mint.

TWILLEY: But not everyone loves mint. Or even gum.

ALISA WEINSTEIN: Most of the mints are terrible and they smell really artificial. So I hate the smell and the sound and the sight.

TWILLEY: That’s right, ladies and gentlemen, we have a gum hater in the house, ready to reveal gum’s dark side. After the break.


GRABER: I have known Alisa Weinstein since I was about three years old. And almost everyone who knows Alisa knows that she absolutely hates gum.

WEINSTEIN: the sound of people chewing, it has got to be the number one thing.

WEINSTEIN: The majority of people just kind of let their jaw fly off the hinges when they’re chewing gum. It’s like a flapping.

WEINSTEIN: And the gum is jostling around, you know, between their teeth and under their tongue and around their mouth. And I can hear that of course, because it makes a squishing sound every time someone makes contact with the gum.

GRABER: Alisa admits that her feelings about gum sounds are a little strong.

TWILLEY: But she is not alone in these anti-gum feelings. Jennifer told us that even among the chicle-chomping Aztecs, the chewing of gum was seen as a little uncouth.

MATHEWS: They had very strong feelings that only certain people should be able to chew gum, primarily young children and old women. Anybody else that chewed gum, they were ostracized.

MATHEWS: So it was well known at least by the Spanish. And we of course have to take these books with a grain of salt, because they’re written by colonizers about the colonized, but they talked about, you know, that sex workers were marked by the chewing of gum that sounded like they were clinking on castanets.

MATHWES: So they would walk along the streets, chomping on their gum, and that was a marker that they were sex workers.

GRABER: This disdain for gum carried on to its heyday in the U.S.

MATHEWS: As we move into the forties and fifties too. Chewing gum was considered, you know, a nasty habit. Emily Post wouldn’t even write about it in her etiquette book for decades. She refused to even address it because she thought it was so beneath even needing to be addressed.

LIZZIE POST: I don’t think she found it a very becoming habit.
POST: The sort of smacking and the popping and the extra salivation. I’m sorry I hope that doesn’t gross your audience out!

TWILLEY: This is the ghost of Emily Post. Not really — but it *is* her great-great-granddaughter, Lizzie Post, who is the co-presideTWILLEY: at the Emily Post Institute and who has written a bunch of books dispensing wisdom on all of today’s thorny etiquette questions. Including when NOT to chew gum.

POST: I mean, first of all, let’s just be real straight, never in a formal situation. You know, if you’re going to a mingling thing for a work event, you do not have gum in your mouth.

POST: If you are meeting your in-laws for the first time, you do not have gum in your mouth, like. You, you really don’t want to be doing this when you’re trying to make an impression on somebody.

POST: It’s not that gum chewing itself is bad. It’s just that it comes with some, some kind of grossness to it. And in etiquette we do try to avoid being gross. (laughs)

GRABER: Lizzie had a list of places you shouldn’t be chewing gum. Do not have it in your mouth when meeting with coworkers on zoom. And definitely spit it out before entering a place of worship.

POST: Yeah, I would definitely avoid places that are sacred first of all. So churches, mosques, synagogues, places where we’re trying to be reverent, you know, not, not a place for gum chewing.

POST: I know that, that museums and places where we are viewing antiques, things like that, often if you can keep it in your mouth and keep it quiet? You’re fine. But if you’re going to be that person, who’s tempted to stick your gum under the bench chair in the viewing room, no!

TWILLEY: OK, *this* is where the rubber hits the road. Literally. A little gross mouth smacking aside, this question of sticking gum on stuff — this is truly chewing gum’s dark side.

WEINSTEIN: Well, if you go outside of my apartment right now and walk down the stairs, there is a giant wad of blue gum that has been smashed into the sidewalk, right in front of my house.

GRABER: Alisa is traumatized by it — and she’s going to have to keep seeing it whenever she walks outside. It’s rubber, remember — it’s a material that repels water and so it won’t wash away in the rain. And so it really never goes away.

WEINSTEIN: That gum has, you know, it’s going to stay there forever. Little, those little bits of plastic are not going to, like, melt, like nicely into the earth, like your little egg carton.

WEINSTEIN: No. That gum is, is built to last.

MATHEWS: So, gum becomes a major nuisance on city streets, particularly in places like New York. And can end up costing major cities millions of dollars a year for cleanup.

TWILLEY: This issue is something that Alisa decided to investigate first hand. She took her fight to the streets.

WEINSTEIN: I got a fax. Like I think there were still using fax machines at that point. I got a fax about happenings around the Bay Area, that I could cover as a cub reporter, like junior reporter learning the trade at UC Berkeley.

WEINSTEIN: And the city of San Francisco was holding sort of a demonstration for companies that could clean gum off the sidewalks. They’d put out an RFP, a request for proposal for gum cleaning services.

GRABER: Yes, this was actually back in the day when people used fax machines. But in any case, Alisa could not refuse the siren call of the power washer.

WEINSTEIN: What I did was I went out with someone power washing the streets in San Francisco, and he actually let me wash gum off the street. He showed me how to hit the gum properly with the extremely powerful stream. And the gum would flatten, and then it would just blow up sort of like off the sidewalk.

TWILLEY: This experience turned out to be positively therapeutic for Alisa.

WEINSTEIN: I think it just felt incredibly powerful to be able to, to hold this very, very sophisticated, but simple machine and just blow pieces of gum off the street. It was great. It was absolutely great.

TWILLEY: To the point where she got a little carried away with her new found gum blasting power, and aimed the jet at one patch of pavement too hard for too long.

WEINSTEIN: And it just dug a hole. It drilled a hole in that blacktop, sent the black top, the debris all over my face and glasses.

GRABER: The point is, as Alisa demonstrated with power washing that could split asphalt, it’s that gum is really hard to get rid of. Cities and businesses pay folks with power washers or with special chemicals that can break up gum to clean it up. This problem is especially bad in hot and humid places because that’s when gum gets super sticky.

TWILLEY: For example, a hot and humid place like Singapore.

JONATHAN LEE: I think two things come to mind when we mention Singapore to anyone who doesn’t live in Singapore.

DEBBIE HA: If you talk to someone who’s actually visited the country on, on, on vacation or something, they would say, oh, it was really clean.

LEE: And most frequently chewing gum, the chewing gum ban that’s notorious throughout the world.

GRABER: Debbie Ha and Jonathan Lee are Gastropod listeners who were generous enough to share their gum thoughts and memories with us. Debbie was pretty young when Singapore banned the importing or selling of gum in 1992—

HA: So, this was told to me from my parents and also probably just from like the TV ads and stuff. But Singapore was going through a period of revitalization and modernization. So the history is that Singapore basically went from a third world country to a first world country within my mom’s lifetime.

HA: So they’re trying to modernize, they’re bringing in trains and elevators and trying to get people to move into, from like small thatched roof villages into high rise buildings.

TWILLEY: But curses curses people were sticking their chewing gum on the buttons of the shiny new elevators, and they were sticking it on the doors of the shiny new trains and everything was getting gummed up.

HA: So Singapore just said, you know, enough of this, we’ll just put in a blanket ban.

TWILLEY: And it worked. The trains and the elevators ran smoothly, and the streets were free of unsightly blobs.

GRABER: Jonathan told us this cleanliness became a source of pride in Singapore.

LEE: I will say, I have traveled quite a bit for work and I’ve been through most of the globe. I’d say. and I’m always appreciative of what we have here in Singapore and that our streets are really clean. It’s never been an issue.

LEE: But in general, I’d say if you ask most Singaporeans, where we are proud of how clean things are in very grateful, how clean things are here.

GRABER: Singapore did eventually decide that things like nicotine gum, gums you use for medical purposes, those are now kosher. And if you bring in gum from overseas to chew just your own little stash, nobody’s going to arrest you. But it is actually still illegal to import and sell normal gum there.

LEE: I reckon if you asked more Singaporeans as well, if you pick nine out of 10 from the streets, they’d be quite ambivalent about gum, they don’t quite miss. I don’t think they quite miss it all that much. To be honest. We don’t, we never talk about it at all.

LEE: I can count with one hand the number of times I’ve seen someone chew gum, in the past 10, 15 years.

TWILLEY: So the Singapore solution is one effective way to get rid of gum on the streets. Alisa of course is available for power washing anytime. And some companies are even trying to collect chewed gum wads and recycle them into things like sneaker soles and so on.

GRABER: But there could be a solution before the gum is a problem – gum companies could take ownership over the problem. I mean, couldn’t they just develop gum that actually breaks down, that biodegrades and washes away?

MESTRES: So they have been developing these alternative gum bases, but you cannot see any of them in the market. The reason is that the chew profile that you obtain for those gum bases is not acceptable by the consumer.

MESTRES: You obtain something that is not, is not really nice to chew when you try to formulate gum bases that are more easily degradable.

GRABER: Much to my personal dismay, the gum companies don’t have to pay for any of that cleanup, so really why would they bother?

TWILLEY: But actually, this problem is sort of gradually diminishing on its own, because Joan told us that gum chewing itself is on the decline.

MESTRES: So gum, nowadays, are losing share, when compared to other confections. These are not good times for, for chewing gum companies.

MESTRES: There are different factors. One of them, for instance, is that gum is considered somehow… I shouldn’t say this word, but dirty?

MESTRES: It is something that, it is not natural. Something that you throw it on the street and stays there for, let’s say forever or for years.

GRABER: Joan also says there hasn’t been a lot of innovation in the gum space, and people want candy that’s new and fun.

MESTRES: So that’s why gum is losing share. And this is bad for me, I would say. (Laughs)

TWILLEY: That said, gum is still being chewed. Bubbles are still being blown. Wads are still being stuck under school desks. It’s still got that nostalgic vibe of American rebellion.

MAN, FROM THE MOVIE “THEY LIVE”: I have come here to chew bubblegum and kick ass. And I’m all out of bubblegum.

GRABER: Even Lizzie Post likes a stick of gum on occasion.

POST: So I’m a, I’m a Big Red fan. I’m a Trident cinnamon fan. I like the cinnamon gums.

TWILLEY: Here’s the deal. Everyone can relax. You *are* allowed to enjoy gum, even in Singapore!. But there should really be rules. First of all for where and when you chew it.

POST: You’re just walking down the street, when you’re driving somewhere, you need to freshen your breath before you get there.

POST: You know, in your own personal time, when you’re not really interacting heavily with people.

GRABER:. But really the most important thing to consider is what to do with it when you’re done chewing.

POST: It is going to be a finger moment. I think the probably least gross thing you could do is by saving the wrapper and immediately spitting directly into the wrapper rather than your fingers and then into a wrapper as like two separate moves.

POST: So I think that would probably be the most elegant way to get your gum out of your mouth.

TWILLEY: Out of your mouth, and, crucially, straight into a bin.

POST: No one else should ever have to interact with your gum. So when your gum lands on the sidewalk, when it lands under a desk, when it lands, across the room, if you’re doing that bubble blowing thing. None of these are appropriate places for it to end up.

POST: It ends up in a receptacle. That’s the only appropriate place for gum.

Does your chewing gum lose its flavor on the bedpost overnight?
If your mother says don’t chew it, do you swallow it in spite?
Can you catch it on your tonsils, can you heave it left & right?
Does your chewing gum lose its flavor on the bedpost overnight?

GRABER: Thanks this episode to Jennifer Matthews, Theis Jensen, Joan Mestres, Alisa Weinstein, Debbie Ha, and Jonathan Lee.

TWILLEY: We’ve got a link to Jennifer’s book, Theis’s paper, Joan’s gum technology blog, and Alisa’s original gum thesis all at Alisa was the original inspiration for making this episode, and we cannot thank her enough.

GRABER: Thanks also to superstar producer Claudia Geib for her help with this episode. We’ll be back in two weeks — but we wanted to leave you with one last bit of gum, the true villain as far as Alisa is concerned!

WEINSTEIN: The gum lobby has really seized on breath and that etiquette as, like, superseding any other type of, of etiquette. Like if you have bad breath, that’s it. You’re — remember the Big Red commercial?

GRABER: That Big Red freshness lasts right through it,

WEINSTEIN: Your fresh breath goes on and on. While you chew it. Say goodbye a little longer,

GRABER: Make it last a little longer,

WEINSTEIN: Give your breath long lasting freshness!

TOGETHER: With Big Red!