This is a transcript of the Gastropod episode, Move Over Gin, We’ve Got Tonic Fever, first released on February 11, 2020. It is provided as a courtesy and may contain errors.

KIM WALKER: But you can try a little bit. It’s a lovely bright orange color, actually. You can’t really see it—but you see on here? Beautiful bright orange.

NICOLA TWILLEY: Yeah, looks like chili oil.

WALKER: Yeah, in a way, yes. Would you like to try some?

TWILLEY: Oh, that’s bitter. Mmm. It’s like, dried out the inside of my mouth where it landed.

CYNTHIA GRABER: Nicky, that doesn’t sound pleasant at all. What are you tasting?

TWILLEY: The things I do for Gastropod. But actually, I was expecting this to taste nice. It’s the basis of tonic water—I was tasting the tonic without the water added.

GRABER: Sounds lovely in theory—though I do happen to prefer mine with a healthy splash of gin.

TWILLEY: It was 9 in the morning Cynthia. But no judgement.

GRABER: Good thing you got an early start, because we need to get to the bottom of this bitter concoction. And we, of course, are Gastropod, the podcast that looks at food through the lens of science and history, I’m Cynthia Graber—

TWILLEY: And I’m Nicola Twilley. And this episode is all about tonic water, the fizzy, usually pleasantly bitter mixer that is joined at the hip to gin. We are currently in the midst of a ginaissance—The New Yorker said so!

GRABER: Okay, but we are also having a tonic—I’m not even going to try—a renaissance in tonic water, too.

TWILLEY: So we found some tonic water obsessives to talk to.

WALKER: Yes. So you spotted that this is my, um, mine and Mark’s eBay addiction of looking for cinchona and quinine related artifacts from the Victorian era. So we’ve got a range of tonic water bottles.

GRABER: Kim Walker and Mark Nesbitt wrote a new book called Just the Tonic: A Natural History of Tonic Water. But—what is tonic water?

TWILLEY: And how did it meet its one true love, gin?

GRABER: And is there any truth to the story that the gin and tonic was invented to combat malaria?

TWILLEY: This episode, we go deep into the South American cloud forest—or actually, a greenhouse in Southeast London—to tell the story of tonic.

GRABER: Cheers!

WALKER: So tonic water that you buy off the supermarket shelves is a fizzy sparkling water, which is flavored usually with a natural quinine. That is still extracted from the cinchona tree and sweetened with sugar or sweeteners and sometimes also has other fruity flavors. But the basic for tonic water is quinine and soda water.

TWILLEY: This is Kim Walker, like we said, she’s the co-author of the new book, Just the Tonic, and she’s working on a PhD about cinchona at Kew Royal Botanic Gardens and the University of London.

GRABER: Before we go any further with the cinchona tree and quinine and tonic water, we need to have a language moment. I’m American, I pronounce the word quinine.

TWILLEY: Kim is British like me, and we say quinine.

GRABER: And we are all going to continue throughout this episode with our different pronunciations. Just so you know.

TWILLEY: On my most recent trip home, I went to visit Kim and her co-author, Mark Nesbitt, at Kew. Mark is head of Kew’s Economic Botany Collection, so that’s where I found them.

MARK NESBITT: We’re sitting in the Economic Botany Collection, which is a collection of about 100,000 useful plants. You know, raw materials, lumps of rubber, lumps of wood, lumps of bark, such as the bark of the cinchona tree. And Kew has around about a thousand specimens of cinchona bark, mostly dating to the 19th century.

GRABER: Okay, tonic water has quinine in it, and quinine comes from bark of the cinchona tree. So what is the cinchona tree?

NESBITT: Well, the cinchona tree is in the coffee family. The plant family Rubiaceae, it doesn’t just contain coffee, there’s other really important plants as well. And it grows in a very particular habitat on the eastern slopes of the Andes. It’s this cloud forest. So quite high, quite wet, incredibly biodiverse landscapes.

TWILLEY: Even amidst all this biodiversity, the cinchona tree stands out.

WALKER: So in 1847, French pharmacist Auguste De Landre saw a cinchona tree for the first time. And he wrote “That magnificent tree. For so long I’d seen it in my dreams. And now it was before me. I lingered in ecstasy, contemplating the silvery bark, those wide leaves with shimmering green and the flowers, such sweet perfume somewhat reminiscent of lilac.” So you get lots of people describing the tree at the time as being particularly beautiful out of all of the trees in the forest, that it towered above the others, and it had these beautiful glossy leaves.

TWILLEY: Fortunately, Kew Gardens has a few cinchona trees, because after a description like that, I really wanted to see one.

WALKER: So we’re at the temperate house at Kew. And this is one of the largest existing Victorian glass houses in the world. Recently renovated. And inside is plants that are from the temperate area. And cinchona is from a tropical place in the South America. But because it grows so high up in the mountains in a cooler temperature, it’s here in the temperate house.

TWILLEY: I have to admit, I was a little disappointed at first, because the cinchona tree was tiny. It was shorter than me!

WALKER: Well, yeah, because these ones aren’t very old in the temperate house, because it’s only just been replanted in the last couple of years because of the renovation project. But in the wild they can tower above the other trees.

GRABER: But what’s particularly glorious about the trees, and what captivated European visitors to the Andean cloud forests, was the cinchona flowers. Luckily, this tree happened to be in flower.

WALKER: So, for example, this one started flowering last February and hasn’t stopped since, but it hadn’t flowered before that for a year or so. And I know of other trees in Britain that haven’t ever flowered. So it is hard to predict. But luckily we’ve got this one in flower today. And until then I hadn’t smelt the flowers and they are just so lovely. So I’m glad it happened while I was doing my PhD.

TWILLEY: They’re gorgeous. They’re also fuzzy. They’re delightful. Cinchona flowers are these tiny fuzzy pink star-shaped flowers—Kim said they look like what she imagines a fairy would curl up to sleep in. And they smell like lilacs.

WALKER: I mean it was very popular as a perfume in the 19th century. You can still buy it in France. It’s called Eau de Quinine.

GRABER: But as entrancing as the cinchona flowers are, it’s not what Europeans really fell hard for. That was the bark of the cinchona tree.

NESBITT: What’s special about the cinchona tree’s bark is that it is pretty rich in quinine alkaloids.

GRABER: Alkaloids are a type of chemical found in plants like nicotine and morphine and cocaine, and this particular class of chemicals also affects us humans.

NESBITT: Why are they there in the bark? Of course, they’re not put there for our benefit. They are put there to protect the plant.

TWILLEY: Quinine, like most alkaloids, is extremely bitter, and toxic at high doses. The way it works to protect the cinchona tree is that if an insect starts to eat its bark, that bitterness is really off putting.

NESBITT: And that’s the first line of defense for a tree is its bark. And then if it keeps on munching away it’s going to be poisoned. Just like humans can be if they consume too much quinine.

GRABER: But in a strange and certainly useful twist, while a lot of quinine might be poisonous, a little quinine is actually a good thing.

TWILLEY: At least if you have malaria.

WALKER: And what cinchona does is it attacks the parasite in your blood and it kills the parasite.

TWILLEY: Quinine has been used to treat and prevent malaria by attacking this parasite for hundreds of years now. We still don’t know quite how it works, but it works.

GRABER: If you aren’t familiar with malaria, it’s a disease that you’re most likely to get if you travel to tropical countries. The malaria parasite is transmitted by one particular type of mosquito. And the parasite lives in your blood and can cause fever, vomiting, kidney failure, even death.

WALKER: When you think of malaria today, you think about, oh, I need to take my anti-malarials because I’m going to a tropical country like Southeast Asia or Africa somewhere. But malaria was all over the world. It was in Britain for sure. And it was even up to the Arctic Circle. So wherever people were, there was malaria.

TWILLEY: Malaria is one of the oldest human infectious diseases and one of the deadliest too—researchers think it’s killed more people than any other infectious disease throughout history.

WALKER: And there’s lots of historical research about how much it had an impact. In particular, if you look at things like the voting in of popes and about how they would have to keep re-voting people in, because they’d die off with malaria very commonly. And then you’ve got some historic figures that have died from malaria that have possibly changed the course of history. So Oliver Cromwell is said to have died of malaria.

GRABER: And malaria is still a big deal today—in 2018, according to the World Health Organization, there were 219,000,000 cases of malaria, and nearly half a million people died. But the biggest effect is how devastating these recurring malarial fevers are to people’s daily lives in Africa. The disease costs tens of billions of dollars each year in lost productivity.

TWILLEY: In richer parts of the world, we’ve mostly eliminated malaria these days—for starters, if you can afford to treat it, and then people don’t have it, your local mosquitoes won’t be carrying it.

GRABER: Also rich countries can afford to put up screen doors to keep mosquitoes out, and they’ve also focused on spraying pesticides, and getting rid of small pools of standing water that mosquitoes love. This is why malaria isn’t as much of an issue in the American south as it used to be.

TWILLEY: But for most of history, malaria was everywhere and there wasn’t a treatment. People took herbal remedies to try to cool their fevers, and they prayed and they wore charms, and nothing actually worked to treat the disease.

GRABER: Until Europeans stumbled upon the South American cinchona tree and its nearly magical, malaria-curing bark.

NESBITT: There’s a long controversy as to whether the antimalarial properties of cinchona were known before the Spanish arrived in Latin America.

TWILLEY: The reason there’s a controversy about this is that malaria was not a big feature of life in South America before the conquistadors arrived. There was a very mild version of the disease in the region, but malaria was not a serious problem in South America until the Spanish colonized it.

NESBITT: Bringing enslaved people with them from West Africa who, of course, had the malaria parasites in their blood. And quinine isn’t very good at treating other fevers. It’s really only effective against malarial fevers. So why would it have been discovered before malaria arrived in South America?

GRABER: Indigenous healers knew the forest and the plants intimately, but if the cinchona bark doesn’t actually treat fevers, and fevers were at the time the hallmark symptom of malaria, there was no obvious reason for the locals and the Europeans to take cinchona bark to cure malaria.

TWILLEY: On the other hand, cinchona bark is bitter, as I experienced, and bitter things were often thought to be medicinal. Also quinine does seem to have a muscle relaxing effect—it’s even prescribed to treat muscle cramps in some countries, not the US.

GRABER: Nobody knows exactly how it does that, and based on existing scientific research quinine doesn’t seem to be super effective at combating muscle cramps and tremors, but you can imagine a scenario where Europeans were shivering from malarial fevers, and maybe indigenous healers suggested something that would calm their shivering muscles down.

TWILLEY: But really, Kim says it’s not at all clear how the connection was made between malaria and cinchona.

WALKER: It also equally might have just been an accident. It might have been that somebody was taking it for something else and then found that they’re also being treated for that. We don’t really know.

GRABER: But however they figured it out, it wasn’t too long before the Spanish colonists started to use cinchona regularly and enthusiastically against malaria.

NESBITT: So if you look at the historical record, the first absolutely certain reference to cinchona is 1633, in a book. And it’s described in terms that make it absolutely clear that we are referring to cinchona here, we are referring to its antimalarial properties.

TWILLEY: In the 1600s, cinchona bark made its way back to Europe, where malaria was still a problem. But people were slow to adopt this new cure. Partly because it was expensive. And partly because they didn’t trust it.

WALKER: One of the earliest names that it was given was Jesuit’s Bark, because the Jesuits were settled in South America and they had outposts and they were very good physicians. And so they were used to using this bark and they’re the ones that brought it first back to be imported into Europe. So it got naturally named Jesuit’s Bark. Which of course, being Catholic as well, that led to some issues with its adoption into Britain because there was some suspicion about possibly a Catholic scam.

GRABER: But eventually the bark did catch on, because it just worked so well, and everyone was desperate for a cure.

TWILLEY: And in the absence of a good origin story about how the miraculous properties of the bark were discovered, people did what they always do, and made stuff up. There were stories about learning the cure from watching mountain lions eat the bark, or jaguars.

NESBITT: So many about trees falling into ponds and people drinking the water and being cured of malaria.

GRABER: But the most popular legend is the one that gave the bark its name.

NESBITT: So the cinchona tree was named first, the Latin name for the genus, was given by the great Swedish botanist Linnaeus. And the origin of that name cinchona, cinchona, CIN, actually lies in a Spanish name, the Countess of Chinchon.

TWILLEY: Doña Francisca, the Countess of Chinchon, was the beautiful wife of the Viceroy of Peru. And the story goes that she was dying of malaria, and she was saved by the bark, and then she went back to Spain and spread the word.

NESBITT: But in fact, the diaries of her husband have been discovered. They didn’t mention her having malaria. Didn’t mention cinchona bark being used to cure her. So it’s pretty much certainly a legend.

GRABER: Yeah, no. But her name lives on in cinchona bark. And a lot of Europeans survived malaria once the bark really caught on in Europe, and then they took this wonder drug and traveled around colonizing the world.

NESBITT: So empire and quinine are very intimately related, in I think ways that we’re appreciating are really complex. So I mean, first thing, it’s an enabler. It’s a way you can move into very malarial zones such as West Africa.

TWILLEY: On early, pre-cinchona European expeditions to Africa, basically everyone died, often from malaria. On one expedition to what’s now Mozambique, 152 men set off and only 20 came home. Another, to Niger, lost 40 out of 49 people.

NESBITT: It was really William Baikie, Captain Baikie, and his expedition of 1854 I think, who, having absorbed the lessons from these earlier disasters, made his men take quinine every day and returned I think without a single death from malaria.

GRABER: This expedition along the Niger River was the first to show that cinchona bark wasn’t just great at curing malaria, but it was also great at preventing it. This is how many travelers take drugs against malaria today—as prophylaxis, not as a cure.

TWILLEY: And it was a transformational discovery. Cinchona basically paved the way for the Scramble for Africa, when European countries raced to grab chunks of the continent for their own empires.

GRABER: And this is also around the time that Europeans start to think, you know, it’s kind of a pain to climb into the cloud forests of the Andes and deal with the locals to get all the cinchona bark we need. We should take the trees out of South America and plant them in plantations where we can have more control over the supply.

NESBITT: So as early as the 1820s, Humboldt, the great German traveler, noted deforestation and cinchona trees being cut down. There have been suggestions that these comments by Western explorers were simply a way of belittling indigenous management and kind of making the case for appropriating the plant. I’m sure there’s an element of truth in that. But nonetheless, quite observant scientists such as Humboldt do tell us that the tree was very threatened.

TWILLEY: Yep, it’s the old “we should take this because the natives can’t be trusted to manage it properly” argument. The British Museum is built on that.

GRABER: And Kew Royal Botanic Gardens actually played a big role in the cinchona theft.

WALKER: In 1859, the India office sent out a guy called Clements Markham to coordinate a collection project. And he went to Peru and another guy called Richard Spruce went to Ecuador and they took Kew horticulturists with them. Both to be able to take cuttings and plant them in cases that could successfully transfer over to India. So it was using Kew’s horticultural expertise to be able to successfully take plants. Remember, going from South America to India would have taken months on a ship. So you do need people that have this expertise.

TWILLEY: As regular listeners will remember from our episodes about stealing tea from China and about David Fairchild’s adventures collecting plants from around the world, stealing plants is not always easy.

WALKER: Clements Markham kept some diaries of his journeys throughout South America. And he does complain about the risks and the tribulations he faces, such as like snakes and having to crawl up on his hands and knees across mountains.

GRABER: And of course Clements had to contend with the natives, and not all of them supported his efforts.

WALKER: He does have local help with some bark collectors. But yeah, you’re right. People were aware that if anybody got their hands on them and could take the tree out of South America, it was going to effectively destroy trade. So he does make quite a swift exit because he hears that—somebody hears that if somebody’s out to get cinchona trees and seeds and he threatens if he catches anyone, they’ll chop off his feet. So Markham actually gets in there and gets out very quickly because there is this risk involved.

TWILLEY: Tree theft successfully accomplished, the British went on to establish plantations of cinchona trees in their colony, India. And the Dutch went and stole their own trees and planted them in their colony, Java—which is Indonesia today.

GRABER: These plantations were successful. By the 1880s, British and Dutch plantations totally dominated the already huge market for the bark. And the South American trade was wiped out.

TWILLEY: In the wild, in South America, explorers had often harvested cinchona bark by cutting down the entire tree. But there was a more sustainable way.

WALKER: One of the traditional methods of harvesting in the Andes was taking off strips and leaving strips on and the tree could recover. And this was taken up in the plantations in British India, where they would—called something like mossing the bark, where you would take off strips, leaving alternate ones—and put moss over the top and tie it up and then the bark would grow back.

TWILLEY: Back in the collections, Kim showed me one of these bark strips that had been harvested in the 1800s. It’s got this nice kind of reddish, mahogany sort of color to it.

WALKER: Yeah. And you can see it’s covered in lichens, which is a feature in the 19th century for recognising if you’d got good quality bark or not.

GRABER: So by the mid 1800s, Europe had reliable sources of cinchona bark. But it’s a long way from a dried out reddish strip of tree bark to tonic water.

MID-ROLL
WALKER: The way that people would have taken initially from the sixteen hundreds on is to grind the bark to small pieces so that of course you can take it easier. And then to usually either to decoct it, which is to boil in water. Or more popularly was to put it into alcohol. And alcohol helps dissolve it a bit, makes it more palatable, of course, and makes it more—well, we know now that it can help absorb it better in the body.

TWILLEY: At the time, mixing meds and booze was the done thing.

WALKER: And wine in itself and other alcohols were considered medicinal in their own right. So you would have categories of things like, what you would take wines for, what you might want brandy for. Some of these I think are still existing today. So when you have a cold people always go “Take a whiskey!” and I think this is one of those things that comes from this period of time.

GRABER: Today, as we’ve said, tonic water means sparkling water, sugar, and quinine. But at the time, hundreds of years ago, quinine in alcohol was only one example of a tonic—tonic was an entire category. It referred to healing substances, mostly plants, steeped in alcohol.

WALKER: So tonic was something that is quite an old term but is about strengthening the body’s own healing abilities and like toning the organs and the systems to be able to come to better health. So in the days pre-NHS, there was a large industry, as there still is today, of people self-treating over the counter and having things that are panaceas that can treat all sorts of things and just make you healthier. So with this idea about tonic and strengthening the body, you often find other additional ingredients that were also believed to strengthen things. So that beef and iron, when you’re ill, you know, people would have things that have got—high in fat and protein. So having beef added to the wine made it sound even more medicinal for you.

TWILLEY: So you could get beef and booze tonics. You could get tonics that contained malt, and chocolate and coffee, even cocaine—anything that could help pick you up, all mixed in with a good slug of fortified wine or spirits.

WALKER: Tonic wines were a nice way to take things because not only does it dissolve things well, but it also makes it pleasant to take.

NESBITT: I think it’s very clear that with things like tonic wine, there’s a fine line between medicine and pleasure. There were I think warnings in the pharmaceutical press about people perhaps starting to consume a little bit too much tonic wine, being drawn too much into its pleasurable aspects.

GRABER: The legacy of these medicinal tonic wines are still around today, and, frankly, are still delicious. There’s all sorts of versions of amaro and vermouth. You might have heard of Campari—that has herbs and fruits steeped in it, it’s a tonic.

TWILLEY: If you’re a Scottish hooligan, you will likely have enjoyed a bottle or five of Buckfast Tonic Wine—that’s a traditional medicinal tonic wine with caffeine that is made by Benedictine monks. It was originally sold with the slogan “Three small glasses a day, for good health and lively blood.” But it’s now become a drink for rowdy youth up north.

GRABER: And at the time that quinine was becoming super popular in Europe because it combated the scourge of malaria, you would of course have taken your quinine in wine, as a tonic.

WALKER: So if you had fevers or something, you went to your apothecary or doctor and was given some cinchona bark, then, they might put it in wine for you, but you might also do it yourself. But the adverts for quinine wines definitely start to become much more popular towards the end of the 18th century and really popular during the 19th century. With the popularization of the press and journals that advertised all these tonics and pills and potions that you could buy. So one of the most common ways that you would find quinine taken is the delectable sounding orange quinine wine, which actually isn’t an orange wine. It’s orange spirits with quinine, which sounds really delicious, to be honest.

TWILLEY: And of course, in the spirit of tonic wines, which were basically cure-alls, quinine wines were advertised as being good for much more than just a spot of malaria.

WALKER: Like we said before, quinine was bitter. And when you taste something bitter on your tongue, it starts with saliva going, it starts your stomach and digestive system juices flowing, which helps you digest food better. So if you’ve got things like indigestion or constipation then you would want bitter things. So they were aimed quite a lot at digestive remedies. But also things like nerve tonics and you see things like quinine pills for the male tonic or for women’s nervous irritability and things like that.

NESBITT: Amongst the many things you can treat with quinine was said to be baldness. And there are lots and lots of 19th century advertisements for hair conditioners containing quinine. And you can still buy quinine-containing shampoo on the internet. Very popular in Russia and a number of other countries.

GRABER: The effect on quinine on hair loss has not been scientifically studied, we are not recommending it here.

TWILLEY: So tonic wines were a thing, and some of them contained quinine. That’s the quinine-alcohol connection sorted. But how did quinine meet sparkling water, and become what we think of as tonic water.

GRABER: The first key innovation that led to quinine water, or tonic water, was actually the invention of a way to carbonate water in the late 1700s. We have an entire episode on that topic called Getting Fizzy With It, I do recommend checking it out if you haven’t heard it.

TWILLEY: It contains the astonishing story of marble cathedral stones being turned into seltzer, plus one of the best La Croix-inspired songs you will ever hear.

GRABER: By the 1820s, people started mixing this lovely new sparkling soda water with wine and fortified wines to make a refreshing drink. And someone around that time got the idea to mix sparkling water with quinine, particularly as the anti-alcohol temperance movement got going in the 1830s.

NESBITT: So there’s an early occurrence of tonic water in 1835 in I think The Bristol Mercury. But it fizzles out. We don’t find advertisements for it much more. And the really critical date is 1858, when Erasmus Bond publishes his patent for tonic water.

TWILLEY: Not much is known about Erasmus Bond, even though he is really the inventor of tonic water as we know it. He sold his fizzy quinine water under the name Pitt’s Patent Tonic Water—it was a medicinal drink and he exhibited at the international exhibition of 1862 with a doctor’s note saying how fabulous and health-giving it was.

NESBITT: The interesting thing about it, of course, is it’s not presented as antimalarial. And there are advertisements for it shortly after production starts that make it very clear, it’s those wider tonic properties that it’s being promoted for.

WALKER: What’s important about Erasmus Bond’s patent as well is that he gives it the name tonic water at that point. Before that it was known as quinine soda water or quinine water.

GRABER: This new tonic water was invented in London, and Erasmus Bond had a manufacturing plant set up in Islington, but the drink wasn’t hugely popular in the UK.

WALKER: You do occasionally find adverts for tonic waters here, but it does take off really is in the tropics. So particularly India, but also references to Hong Kong.

TWILLEY: Doctors and travel advisory books had firm thoughts on what Europeans needed to drink to stay healthy in the heat. Alcohol obviously had its own medicinal properties, but experts were united in advising that cooling drinks were essential.

WALKER: One thing is quite common is that sparkling waters are good for the Europeans in tropical countries. And so you start fairly quickly, by the 1860s, very early 1860s, to start seeing adverts for tonic waters in newspapers in India and Hong Kong. They are again for digestion and for acclimatization. But also you start getting this, also, it has quinine in and therefore there’s the association with malaria. So they start saying potentially that these are protective for malaria. And so they definitely start taking off at this point.

GRABER: So by the 1860s, Brits were drinking tonic water in the colonies, even if they were not drinking it in the UK itself. But it wasn’t yet mixed with gin.

WALKER: And then within 10 years of the first tonic water, you get the very first reference to the gin and tonic cocktail, in 1868 in India. It is a bit more of a complex story about how the gin and tonic came to be invented. The reference in 1868 comes from a sporting magazine and it’s talking about a party after a race where people are just about to go home from a party and they’re shouting for cigars, and gin and tonics, and brandy and sodas.

TWILLEY: To quote, “Loud cries of gin and tonic, brandy and soda, cheroots etc. told us the party was breaking up for the night, and we wended our way home.”

GRABER: Should I know what a cheroot is? Is that a drink I’ve been missing out on?

TWILLEY: Hah, you are clearly not a member of the Anglo-Indian elite. A cheroot is a thin cigar, kind of like a Swisher Sweet but not flavored.

GRABER: Swisher Sweet? I had to look that one up—clearly I am not up on how to smoke. Either in the past or today.

TWILLEY: But our point here is the gin and tonic. They’re calling for a gin and tonic with their cheroots as if this drink is an old friend.

WALKER: So it’s not, not just invented gin and tonic tonight in 1868, but it’s obviously been around. And we don’t know who particularly invented it.

GRABER: Whoever had the brilliant idea to add tonic water to gin, they were piggybacking off a long tradition of gin drinks.

WALKER: One of the most popular ways or a couple of the most popular ways of taking gin around this time, one is in gin slings, which is gin and soda water. The other is gin and bitters, which is gin with something kind of like bitter flavoring, like gentian or angelica. And it just seems very natural that the two would merge. And actually with tonic water being available as a bitter soda water, it just seems the perfect pairing.

TWILLEY: One of the enduring myths of the gin and tonic’s invention in Anglo India is that it was invented as a medicinal drink—that this is how the colonial elite took their daily dose of quinine to prevent malaria.

GRABER: But Kim and Mark say that there’s a number of reasons that can’t possibly be true. First of all, the British army wasn’t taking their quinine in gin.

WALKER: It was just as likely to be as whatever’s handy. So rum, brandy and arrack, which is a local sugar cane, distilled alcohol in India.

TWILLEY: And the other thing is that, as delightful as a gin and tonic certainly can be, it isn’t actually effective as a prophylaxis.

NESBITT: In fact, the dose of quinine within your standard gin and tonic is too low to give you significant protection against malaria.

WALKER: But I think these mythologies have just come about because nobody really knows. And you’ve got all these strands of when did you take your quinine? How often would you take your quinine? It was taken in alcohol. And just naturally this myth has arisen.

GRABER: By this point, in the late 1800s, gin was already hugely popular in England. There were even pubs called gin palaces that had no seating and could serve thousands of gin drinkers every day.

TWILLEY: London was awash in gin—people drank 14 gallons per person per year, on average.

GRABER: But Londoners weren’t drinking it with tonic water.

NESBITT: We do have a marvelous complaining letter from The Sporting Times of 1881 saying why in the name of all that is mysterious is tonic water not procurable in England, the land that boasts almost every form of mineral water. Just come back from India. Can’t find it anywhere. I want to put it in my brandies and gins. I want to put it into a gin and tonic. So clearly by 1881, so fifteen years after gin and tonic first appears, it’s not reached Britain.

TWILLEY: Turns out, the arrival of the gin and tonic in the UK is even more of a mystery than its invention in India. This is the problem with trying to untangle the history of alcohol. People aren’t writing stuff down and especially where alcohol is involved, stuff gets forgotten.

NESBITT: We’ve done a lot of work on digitised newspapers on this. And we really first pick up the gin and tonic in a big way in the 1920s. Lots of references to its consumption in hot weather, warm weather. Tonics and warm weather go, just like in India, together. And those references are mostly in drink driving cases where the driver’s consumed one, two, three or four gin and tonics. It’s quite easy to consume gin and tonics in large quantities, they are very refreshing. And then they’re being caught by the police. Now, the tricky thing about that evidence is, does it pick up, actually, a crackdown on drink driving or you know the widespread appearance of motor cars?

GRABER: Unclear, but what is clear is that at some point between 1881 and the 1920s, gin and tonics had arrived in England, and had really caught on.

TWILLEY: The arrival of the gin and tonic in the US is much better documented—

NESBITT: In particular because it followed on the push from tonic water manufacturers.

GRABER: Prohibition ended in the US in 1933 and the tonic water manufacturers were ready. Schweppes’ first advertising campaign in the US in 1933 for their Indian Tonic Water was specifically for gin and tonics. Canada Dry launched theirs at that point, too.

NESBITT: That pre-war arrival of the 1930s was stymied by what happened in the Second World War, when supplies of quinine that by then were being grown in plantations in the Far East dried up and quinine was then reserved for medical use.

TWILLEY: Tonic water was actually rationed in the UK during the war. After victory was declared, Schweppes took out a big illuminated billboard in Piccadilly Circus announcing that gin and tonics could flow again, hurrah! And they launched a major advertising campaign in the US too.

NESBITT: Really pushed tonic water. And they pushed it as a sophisticated drink, initially catching on in cities like Washington but then spreading far into the United States. And it was very clear in that case that tonic water led and gin followed.

GRABER: But the gin and tonic fell into a decline. By the 1970s, it was considered boring, it was seen as a middle and upper class drink that your parents might have at the golf club if they belonged to one. Not too sexy.

TWILLEY: That all changed with the rise of craft spirits. Tonic might have led the way in the 1950s, but gin was the inspiration for today’s renaissance. First there was Bombay Sapphire in the late 80s, that was the first new hot premium gin—

GRABER: But the gin explosion really started up after the turn of the millennium, basically in the past two decades. In the UK and from state to state in the US, governments got rid of laws that prohibited small scale distilling. And so people could make craft gin. And they did. An amazing variety of gins.

WALKER: And now we have so many. If you go to a gin shop, you’ll see hundreds and hundreds of different flavors and different brands.

TWILLEY: Do I get to say ginaissance again?

GRABER: Only if you really want to.

TWILLEY: It’s real. In the UK gin sales rose by more than 40 percent last year alone.

WALKER: And following on from the artisanal gin came the artisanal tonic waters, particularly started off by Fever Tree in 2005. And since then we’ve even had more tonic waters and tonic syrups have now reached the market.

NESBITT: The value of a tonic water trade in the UK alone is what, around about 40 percent now? A little bit higher, of the gin market. That’s a lot of money being spent each year. I do think it’s quite exciting. It’s opened opportunities. I mean setting up a gin distillery—a lot people have done it. It is quite complicated. Making your own tonic water. Experimenting, for example, using raw cinchona. You can do all kinds of cool things with a very small budget.

GRABER: You can find all sorts of artisanal tonics at the market these days. All the tonic waters of course have quinine—they have to be tonic water—but they also have elderflower, hibiscus, cardamom, ginger, rosemary, all sorts of delicious herbs and berries and flowers.

TWILLEY: My current favorite tonic is made using only native herbs and plants grown along the California coast—I love it.

GRABER: As Mark says, it doesn’t take much money to get into the tonic water market. It’s not hard to buy cinchona bark, and then you can steep it to make quinine and then add citrus and any other sorts of herbs or plants.

TWILLEY: When I visited, Kim had made some of her own tonic extract that I got to try—it looked like pencil shavings of bark in alcohol. It was reddish colored and it was really bitter.

WALKER: Yes, so that’s just an alcoholic extract. And you would—I would take that and maybe put teaspoon in some soda water. But it lacks the sugar to balance out the sweetness. But I prefer it without the sugar.

GRABER: But Kim wouldn’t give up her secrets about how to make it, and she doesn’t recommend doing it at home. Because tonic water has a legal maximum safe amount of quinine in it—

WALKER: But using kitchen equipment, you get like five or ten times that amount, not just quinine, but other alkaloids. And therefore, it’s very easy to overdose on it.

TWILLEY: Kim did give us a good website for information on how to make tonic water safely, if you do want to do that, so we’ve got that link on the episode page at gastropod.com.

GRABER: As I said, every single bottle of tonic water, homemade or store bought, contains quinine from cinchona bark. Where does that cinchona come from today?

WALKER: So the bark for this comes from the 19th century established plantations which still exist today. So there’s a few plantations still around. Fever Tree gets theirs from the Democratic Republic of Congo and Kew’s tonic water maker sources theirs from the Javanese plantations.

TWILLEY: Mark said there’s actually more cinchona bark available than there is demand. At least in the plantations. Not so much in the cloud forests of the Andes.

WALKER: So botanists from Kew and from Copenhagen have done some expeditions to South America to try and record the cinchona that’s there. But they’ve noted that it is very difficult to find now because of climate change, because of deforestation and competition in the same area from things like coca farms for producing cocaine. So it is very difficult to find, because of this original overharvesting and also because of different pressures nowadays.

GRABER: And so the trove of centuries-old cinchona bark that Kew has is actually incredibly valuable and important.

NESBITT: Huge wild populations of cinchona have disappeared. And there are really key scientific questions about why plants produce alkaloids? What’s the relationship between soil, the microbiome in the soil, the environment, the species. And these lead to these different combinations of amazing chemicals.

TWILLEY: The cinchona bark that Kew botanists collected back in the 1800s is actually the key to answering a lot of those questions, given that there are so few trees left in the wild.

GRABER: Mark and Kim are collaborating with scientists in Copenhagen, they’re studying the chemistry and DNA of the Kew bark samples.

NESBITT: The quantity of quinine in our 150 year old bark specimens is very similar to what was recorded by 19th century scientists. So it’s a really exciting opportunity here to take the insights from DNA, which tells you what species it is, perhaps even where it grows, to look at the chemistry. And to partly follow in the footsteps of those Victorian explorers and understand quite a momentous moment in the history of medicine, history of science.

TWILLEY: That’s exciting research, but Mark says it’s also really important to preserve whatever is left of the wild cinchona population, so we don’t lose it altogether.

NESBITT: There is actually a really urgent need to understand the current status of cinchona trees. to look at what’s happening to the populations. To think about ways of working with local people, with anyone who’s using these populations today, to preserve them into the future.

GRABER: But probably not for tonic water, or for medicine. Quinine is still used as a malaria drug, but only when the disease is resistant to other drugs. The side effects can be really bad, particularly for your heart and kidneys. Quinine can mess up your heart rhythm and cause kidney failure and in extreme cases lead to death.

TWILLEY: These days malaria is treated and prevented mostly by chloroquine, which is a synthetic chemical developed in the 30s as a substitute for quinine.

GRABER: But of course you can find plenty of quinine around—it may not be in your medicine cabinet, but it is in your liquor cabinet.

TWILLEY: It’s in tonic water, of course, but it’s also a key ingredient in Aperol—the base of a million refreshing spritzes. And Fernet-Branca, which is another aperitif.

GRABER: And not only can you try quinine in a variety of beverages, but you can also make a variety of beverages with tonic water. It’s not just for gin.

WALKER: Throughout the research we found historical ways that people were using quinine—not necessarily tonic water so we have been a bit cheeky about the cocktail recipes—but how quinine and how cinchona bark could have been used and what alcohols it had been put in. And so we went on a period of experimentation, which is possibly one of the most enjoyable parts of the book, of using tonic water and mixing it with other alcohols. And you know what? It works so well with many things. So some people might have heard of rum tonics and whiskey tonics. I think it’s time for these to be re-embraced.

TWILLEY: If you’ve been lucky enough to enjoy a portônica—port wine and tonic—which is basically the national pre-dinner drink of Portugal—then you will already know that tonic goes wonderfully well with much more than just gin.

WALKER: But one of my personal favorites is getting chilled red wine or chilled white wine in a chilled glass because you just don’t want to use ice and then mixing it 50/50 with tonic water. It makes—a bit like, you know, like a sangria or some places mix Coca-Cola with wine, tonic water with wine, white or red, is a really refreshing lovely drink.

GRABER: I think I need to go make a drink, right now. And for that I can thank Kim Walker and Mark Nesbitt, they’re the authors of the gorgeous new book Just the Tonic. It’s particularly fun if you enjoy old botanical images and advertisements. And buying it supports Kew Gardens!

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