Savor Flavorby Cynthia Graber and Nicola Twilley, on Gastropodwww.gastropod.com

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MH: Fantasy flavors could be Juicy Fruit, Red Bull, root beer, blue raspberry these are delicious flavors that are consumer known but they just don't really exist in the world. Meaning you can't just go and squeeze a root beer flower.

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NT: That was Michelle Hagen. Shes a flavorist at Givaudan, which is the largest flavor and fragrance company in the world.

CG: Wonder what a flavorist is? Stay tuned. This episode well be getting the history and science of artificial flavors, from long-forgotten grapes that inspired that weird fake grape Jolly Rancher flavor to the designer microbes fermenting the flavors of the future.

NT: Its just another day at the office for Gastropod, the podcast where we bring you the best in food science and history. Im Nicola Twilley - CG: And Im Cynthia Graber. Before we get into flavor, we have a favor to ask of you all.

NT: Next month were doing an entire episode on cocktails! So we want your favorite cocktail stories. Delicious new creations, signature drinks, the ones that flopped..

CG: Oooh, do I have a cocktail recipe that flopped.

NT: Record us a voice memo on your phone and email it to us, or leave us a message at 310.876.2427.

CG: And now, in this episode, I ask Nicky the question youre all wondering. What in the world is the difference between a natural and an artificial flavor?

SKITTLES MUSIC

NT: To answer that questions, I kind of need to go back Im going to have you open a couple of packets of Skittles. The first is a normal package of original Skittles.

CG: Which I have right here.

POURING IN

NT: We are going to do two separate experiments that will help us get at the nature of flavor. Because I think a lot of people think flavor is sort of identical to taste. But taste is a sense. Sour sweet salty bitter. Theres debate about how many different tastes we can sense and how it works. But it's fundamentally different from flavor. Flavor is a lot more than just taste. And its a perception not a sense. Which means it happens in your brain.

CG: Okay, so lets start that off, first I tasted a purple Skittle. It has that fake sweet grape candy flavor I expect it to have.

NT: So now youve ground-truthed Skittles, now I want you to close your eyes, pick one at random from the regular batch.CG: Okay Im picking one at random.NT: And then when you put it in your mouth, Id like you use your other hand to hold your nose as firmly as you can.CG: This is going to be challenging to tape at the same time.NT: Your third hand, your fourth hand holding the recorder. Do exactly the same thing and then tell me what flavor your Skittle is.CG: Okay my nose is plugged. I can't even say that. Now I'm going stick to the Skittle in my mouth.NT: Don't unplug your nose until it's fully gone.(CHEWING)CG: I can't chew and breathe at the same time.(LAUGH)NT: It is tricky.CG: Okay I'm going to unplug my nose.NT: What flavor was that Skittle?CG: Well now that I unplugged my nose I actually have a different guess. Because there is little left in my mouth. I would have guessed maybe I don't know orange red it just was really sweet. And now that I unplugged my nose I think maybe if the green one.It was hard to tell. When I unplugged my nose I got more of a tart sense, with my nose plugged all I got was sweetness. I couldn't really tell.

NT: And that is the point of the experiment. Upwards of 70 percent of flavor consists of smell. By the way, if you listeners try this at home, it helps to be in the same room. Because I was in Brooklyn and Cynthia was in Somerville, I had no idea which flavor she had picked either.

CG: We will never know.

NT: Lost to history. But it doesnt matter. The point is, a lot of what you think of as flavor is actually something called retronasal olfaction. So normal olfaction, thats smelling through your nose. The retronasal kind happens through another passage at the back of your mouth. Youre not normally aware of doing this, but when youre chewing on food, little puffs of the aroma chemicals are going up a passage that runs from the back of your mouth all the way up to your nose.

CG: That is why when I had my nose plugged, those puffs of Skittle flavor werent going anywhere.

NT: Exactly, and all you got was the taste sweet. Its the same reason why food tastes blah when you have a cold. Okay, now on to experiment number 2.

CG: More Skittles!

NT: A special packet that I brought you all the way from England. Its called confused Skittles, and the deal is - they are all the wrong color.

CG: So the lemon one is not yellow, and orange is not orange, etc.

NT:. So why don't you help yourself to a confused Skittle.CG: Okay - should I do the purple one again?NT: Yeah do the purple one what are you expecting?CG: I'm expecting it to take just like the other one I tasted earlierNT: Right and let me knowCG: okay, so maybe I shouldnt have done purple. Because Im expecting it to taste like the one I tasted before and it's different.NT: No, tell me what flavor it isCG: I have no idea. it's definitely not grape or that fake grape flavor it's not the same thing that I just ate. But I don't know what it is.NT: See, and that is precisely the point of these confused Skittles. Is that without the cue of knowing that purple means grape youre kind of stuck for knowing exactly how to describe what it is that the flavor is.

CG: Listeners, you can replicate this at home with regular Skittles by closing your eyes and having a friend chose the Skittle youre going to eat.

NT: The point of it is to show that even though flavor is a little bit based on taste, and a lot based on smell, it also is shaped by all your senses including vision.

CG: But I have a question. Im convinced by this experiment that I cant tell the difference among artificial flavors if my eyes are closed. But I am not convinced this is true for real food as well. If I had a blindfold on and somebody handed me two glasses of juice, would I really not be able to tell the difference between orange juice and apple juice?

NT: Its actually harder than you think, when you cant see. Theres this famous experiment that I like that showed all these celebrity wine critics believed they were drinking red wine when they were actually drinking white wine with some food coloring added. It was how it looked. And all of them believed they could tell the difference between white and red wine on taste alone. That the color didnt make a difference. I mean, of course, theyre wine critics, this is what they do. But it turned out they couldnt.

CG: Fascinating. So it really is like chefs say, you start to eat with your eyes before you ever take a bite.

NT: Flavor is a truly multi-sensory perception. And you can put the Skittles away now.

CG: Thank you. Okay. Thats flavor. But what about flavors? I see flavors listed on ingredients in the grocery store. What are those?

NT: Obviously food has flavors. When you eat a strawberry, you are tasting or really, as we now know, mainly smelling the chemicals that make it strawberry flavored. As it happens, there are more than 350 different chemicals that make up that strawberry flavor.

CG: So I put the strawberry in my mouth, I start chewing, and those 350 chemicals, theyre going up into my nose for me to feel like it tastes like strawberry.

NT: Little puffs of methyl butanoate, ethyl pentanoate, and gamma decalactone.

CG: That is some impressive pronunciations. Clearly youve been practicing.

NT: Dont ask me to do all 347 please.

CG: But theres no flavoring on the label a strawberry box, obviously.

NT: Yes, and thats because for a flavor to have to be listed on a label, it has to have been added to the food its not just in it, like those chemicals are naturally in a strawberry.

CG: Okay, so what about those added flavors? I mean, I doubt that theyre adding 350 flavor chemicals to a strawberry Starburst.

NT: Or a Skittle for that matter. And this gets us to artificial flavor. For most of human history, honestly, if you wanted a strawberry flavor thing, you would have just had to use a strawberry. But that all changed in the 1800s. Two things happened that, on the surface, seem to have nothing to do with food. But to go back in time to invention of the very first artificial flavors, I sat down with Nadia Berenstein. Shes getting her PhD at the University of Pennsylvania in the history and sociology of science.

NB: My dissertation is about the history of synthetic flavors and of flavor science in the United States from about 1880 to 1970.

NT: So the first thing to know is that until the 19th century, there was no organic chemistry. People thought that was no way to recreate any of the basic, carbon-based chemicals of life in the lab. And then one German guy made urea.

CG: Its funny that a major change in science came about because someone created the main component of urine - usually its made in our kidneys.

NB: Yes. He says I can make urea without a kidney either of man or dog. I can synthesize it here in my laboratory from other chemicals. So that's part one of the story. Part two is coal. Industrialization. Organic chemistry is carbon chemistry. And coal processing, coal industrialization, produces all of these byproducts such as coal tar basically that are carbon-rich.And what these are are just raw materials for this burgeoning organic chemical industry that is proceeding by transforming all of these waste products these carbon-rich waste products into other kinds of valuable things. Such as dyes, drugs, perfumes, and artificial flavors.

CG: What do byproducts of coal have to do with artificial flavors? Okay, they have chemicals left over from processing coal and so. So what? Are you saying that coal by-products taste like strawberries?

NT: Weirdly enough, yes. Diluted, a lot of these by products carbon-based molecules called aldehydes and esters they smell fruity.

CG: But why did anyone get the idea to taste them - and then even put them in food?

NT: Yeah. I actually asked Nadia exactly that question.

NB: that's a great question. So chemists, alchemists, the whole history of working with materials chemically has always paid close attention to the smell and taste of substances. This is a way, especially before modern chemistry, this is one of the main ways that you know what something is, by the way that it smells or tastes. So the taste and odor and aroma of different chemicals has always been part of the chemical record, of chemical practice. What happens in the late 19th century is that somebody realizes that chemicals can have a commercial value for these properties, for the ways that they are sensed.

CG: When do they become part of food - what are the very first artificial flavors used in?

NT: Nadia told me no one knows exactly when the very first artificial flavored foods were sold, or even what they were, but the first time they ever get mentioned in the newspapers is in 1851. Theyre enough of an exciting novelty at that point to be included in the very first Worlds Fair, the Crystal Palace exhibition in London.

NB: It is this kind of giant Victorian enterprise of bringing together all of this stuff from all over the world. And this includes really valuable things like the Koh-i-Noor diamond and also just sort of miscellaneous manufactured items. Sailors valentines so like artwork that is made by sailors out of seashells. They've got model dinosaurs that you can sit in and have dinner. I mean basically the Crystal Palace exhibition has everything. And one of the things that it has are these exhibits by producers of synthetic perfumes. And this is where the first artificial fruit ethers enter the historical record.

NT: They were displayed in the chemicals section, in the form of little lozenges, like hard candy. They had pineapple, pear, apple, and grape flavor.

CG: I can imagine why this would have been astounding. In the mid 1800s in London, it would have been nearly impossible to get your hands on some pineapples. But how did it get from this novelty, a wonder of the world really, to getting into peoples everyday diets?

NT: That has to do with another big shift that is happening in the late 1800s. NB: In the middle of the 19th century, late 19th century, with just great advances in sugar refining, huge increases in the role of sugar in Western diets, there is kind of this mass consumer economy for sweetness. And artificial flavors artificial fruit ethers, like the ones that I described kind of come in to accompany sugar on its quest to encompass more and more of people's daily calories.

NT: So those early artificial fruit flavors were used in all kinds of sweet things: candy, soda, ice-cream, and cordials.

CG: What did people think of these new flavors? Were they suspicious or were they kind of wowed by them?

NT: Again, thats exactly what I asked Nadia.

NB: Well it is hard to know exactly. As always in the historical record the voices of just every-day people are notoriously absent. But what we do know is that they caught on relatively quickly. I look at the United States in particular so I know that they were used and sold in the United States starting in the 1860s and 1870s.

NT: Nadia actually showed me tables of formulas for mixing up different artificial flavors raspberry, melon, black cherry, even gooseberry. But whats interesting about this, for me, is youre not analyzing a raspberry or a gooseberry and trying to recreate their flavor. Youre just mixing different proportions of a basic set of about twenty chemicals. Youre working backwards in a way, just combining the chemicals you have and waiting until you can say, oh wait, this smells like a raspberry.

CG: But we already established that a berry, a strawberrys flavor is made up of 350 different chemicals.

NT: More even!

CG: So I imagine that theres no way that these first artificial flavors can be anything like the real thing.

NT: They werent. But they really couldnt be. People just didnt have the tools at that point to analyze all the flavor chemicals in a strawberry.

NB: In the late 19th century you already have people doing nutritional chemistry, you can identify proteins, fats, carbohydrates. In the 19-teens you have vitamins are first identified and discovered and there is a lot of research into vitamins and synthesizing vitamins.But flavor chemistry kind of lags behind. Studying precisely the chemicals that contribute to the odor, flavor, aroma of different foods. And theres a few different reasons for this. One is that it's really hard to do.The proportion of chemicals in food that contribute to, that produce flavor are really small tiny amounts. The other thing about flavor chemicals is that they tend to be very volatile. Theyre unstable, theyre reactive. And trying to isolate this small amount of these particular chemicals that are contributing to our perception of its flavor is a super rough task.

NT: And that actually brings me to something important that happened at the turn of the century. In 1906, this law was passed, the Pure Food Act. It was the first piece of food regulation in America, and it distinguished between artificial and natural flavors for the first time.

CG: Why did this get passed? What were people so concerned about at the time?

NT: Yeah, its an interesting phase in American history because America was just becoming majority urban. People were moving to cities, away from where their food was grown, and that gap between producer and consumer, that was starting to grow for the first time. There were all sorts of food scares and food scandals and fears about whether the bread or milk or meat you were buying in the city was what it said it was.

NB: So the 1906 pure food law. People usually remember this law as the thing that came out of Upton Sinclair's The Jungle. Right? It shut down these horrible meat-packing plants. It was this law that instituted food inspections. That was there to protect public health. But it also aimed to protect the general public, consumers, from fraud. And from these increasingly sophisticated chemicals that were being developed by industry to make food appear better than it was, so to speak.

NT: Chemicals like artificial flavors.

NB: So the 1906 law is the thing that kind of institutes in the regulatory landscape this distinction between genuine and imitation. The thing is, though, with most flavor additives being classed as imitation including vanillin synthetic vanillin, which many many manufacturers of vanillin protested was exactly the same molecule as that found in vanilla beans. If you included it in your vanilla extract you would have to disclose the fact that this is imitation vanilla, not the real thing.

CG: Vanilla and vanillin: thats an interesting one. Vanillin is the name for the main chemical component of vanilla. And it is used absolutely everywhere these days. Ninety-five percent of the time you think youre eating something that is vanilla flavored, its actually vanillin. And it does not come from a vanilla bean.

NT: Actual vanilla contains a ton of different flavor chemicals hundreds, like strawberries. But lets do a taste test and see if you can tell the difference.

CG: So I am standing in my kitchen, and I made three containers that have completely plain drinkable yoghurt. Theres nothing in it other than milk and cultures. In one I mixed in some artificial vanillin, in one I mixed in some vanilla extract, and in one I mixed in vanilla bean. And Im going to do it all blindfolded and see if I can taste the difference. I mixed the vanilla extract and the vanilla bean separately in case I could tell by the texture, the grittiness.

NT: I like this, science.

CG: So, lets see, Ill pick up this one here, try not to look at it. Its a little bitter because I put a lot of vanilla in, but its got a really rich vanilla scent, and I am going to guess that was the real deal.

NT: Okay.

CG: Im going to try the one in the middle. Im not getting as strong a smell. Which means the first one I think was the vanilla bean. I taste the alcohol, and it tastes pretty flat. I have to say my real vanilla extract is pretty old, but Im going to guess the second one is the artifical one. So now Im going to go for the last one. Between two and three, let me see - no actually, now that Ive tasted number three -

NT: Yeah?

CG: And went back and tasted number two again, I think number two has kind of a rounder more rich flavor to it -

NT: And three is like what?

CG: I think three just has that straight vanilla kind of vanilla ice cream flavor. Lets see if I was right. Ooooh! I was!

NT: Woo-hoo! I think thats true. In my experience at least you really can tell the difference between vanilla that has been extracted from seed pod versus vanillin. Its one note, literally.

CG: It really is. Now that I know and I was tasting back and forth, the one with the vanilla bean has the richest smell to it. But the two with the vanilla extract, the one that has the real vanilla extract, its just a more complex flavor to it. Theres more to it, more depth to it.

NT: They are different, but both of them have one identical molecule in common: vanillin. Vanillin is the same, whether it comes from a vanilla bean or not. Its the other stuff in the bean that make the difference.

And this distinction became crucially important after the 1906 law. Because the people who made these artificial flavors had to show that the flavor molecules in their products were the same as you would find in the real thing. And that led to some interesting discoveries. Like grape. Remember back to that grape-skittle flavor?

CG: The one that tasted really sweet and fake and like grape jelly.

NT: Thats the one. That flavor comes from a chemical called methyl anthrinalte. Back at the end of the 1800s, people had isolated this chemical from orange blossom, bizarrely enough, and realised it reminded them of grapes. And they figured out how to make it cheaply from coal tar, and then it became the go-to grape flavor. Its still the one we use today. But it didnt come from grapes, and they had no idea whether you could find this chemical in real grapes. Which was a problem.

NB: In the early 1920s chemists at the USDA trying to enforce the Pure Food Law, recognizing that a lot of artificial flavor manufacturers are selling this chemical in compounds that are grapes flavored, try to come up with methods for detecting it in food.So to do this they analyze things that they know are adulterated and they also analyze genuine grapes juice. And they find that in grapes juice from genuine grapes, there is quite a bit of methyl anthrinilate. So this chemical that a synthetic chemical that is used in these artificial grapes flavors ends up being discovered, confirmed to be in actual grapes.I love this story in particular because the grapes that people were eating at the beginning of the 20th century included a lot of these Vitis labrusca varieties.

NT: Vitis labrusca are the native American variety of grapes. Concord is the most famous, but also Catawba, Delaware, Isabella, and so on. And, in an era before widespread refrigeration, most Americans who had eaten grapes would have eaten these native grapes. NB: The grapes that we usually find in grocery stores now the red and green seedless from California and Chile these are not varietals that have this chemical in them. So in a certain sense when you have a grape Jolly Rancher you are tasting this spectral grape of the past. This sort of spectral grapes orchid. All of these American varieties of grapes that we are no longer familiar with but which the chemical continues to be associated with our idea of grapes flavor.

CG: So not only is fake grape kind of not fake, but its even more American than what we think of now as grapes. But I have to say, the grapes shes talking about include Concord grapes. Some of us who grew up with Manischevitz have never forgotten them.

NT: For when only the most authentic grape will do. But this story gave me an excuse to ask Nadia about one of my favorite urban myths, which is that fake banana tastes so weird and not like bananas because it actually tastes more like a kind of banana that you cant taste anymore. The Gros Michel banana, to be specific. That was the only kind you could buy. But then it went extinct in the 50s from a nasty fungal disease. And now we eat the Cavendish variety.

NT: You know like a lot of urban myths, there is a kernel of truth. I think. I haven't had a Gros Michel banana but according to what I have read about it it does have more of this amyl acetate, isoamyl acetate kind of candy-like flavor, kind of like banana circus peanuts, I think is the candy that has this fake banana flavor, the thing that we think of as fake banana flavor.

NT: Hmm. So I guess a maybe on that myth. Fake banana candy might actually taste like extinct real bananas after all!

CG: That makes me wish I could go back in time and try those bananas. But you know the situation with flavor today is far different from fifty, a hundred years ago. The big difference is that, today, flavors are added to all sorts of foods. Especially processed foods. Howd we get from adding flavors to candy to - I dont know - adding them to all sorts of different foods.

NT: Im in CVS, some HoHos. Sugar is the first ingredient. Soy flour, mono and diglycerides. Natural and artificial flavor.

CG: Fage total all-natural Greek yoghurt. And the ingredients are, cherries, cane sugar, water, corn starch, cherry juice concentrate, lemon juice concentrate, natural flavor, xanthan gum.

NT: Some Red Bull. This is the yellow edition tropical - it even says artificially flavored on the front. Ingredients: carbonated water, sucrose, glucose, citric acid, taurine, sodium citrate, caffeine, blah blah blah, and natural and artificial flavors.

CG: Naked 100% Juice Smoothie Green Machine. A blend of five juices with added ingredients. Apple juice, mango puree, pineapple juice, banana puree, kiwi, spirulina, natural flavors.

NT: Honey Bunches of Oats, with real strawberries. Natural flavor.

CG: 365 Cheese Puffs. Natural butter flavor.

NT: I know I promised to explain the difference between natural and artificial flavors. We will get to that in just a few minutes. But first, lets talk about why there are so many added flavors in our foods in the first place. Its tied to major changes in how and where food was made. And Nadia says it all starts in the 1930s.

NB: In the 30s when you have the increasing sophistication of food processing and food manufacturing. When you're making more and more foods in factories, so spiced meats, baked goods, sodas, candies, all kinds of you know, the beginning of frozen foods, right suddenly flavor becomes a problem. They need to make sure that each item that comes out of their factory taste the same. That it tastes the same around the country, that it tastes the same all year long. And they find that all kinds of crazy things start happening to the flavors of foods once they are being manufactured in factories. Flavors change. A lot of things develop these off flavors that are kind of mysterious.And so what food manufacturers need is a way of controlling the flavor in their foods, right. And so flavor becomes this technical and scientific problem.You really can't have a national or a global food system that is based on processed foods without flavor chemicals, without flavor chemistry. It is just a cornerstone of it. Without this flavor additives the whole system falls apart.

NT: Artificial flavors start off as a way to get us to eat more sugar. Then they become a way to make us eat more factory food.

CG: And now its time for you to explain the difference between natural and artificial flavors. From what I understand, Nicky, natural flavor in, say, strawberry yoghurt, doesnt mean that the flavor comes from strawberries. So what is the difference between natural and artificial?

NT: Well, in 1906, like we said, if your flavor chemical was the same chemical that naturally occurred in a strawberry then it was not imitation. It was real. But as the century went on, the FDA decided that needed an update. The latest version was originally drafted in the 70s. And it spells out the difference between natural and artificial flavor in the most delightful government speak. A natural flavor or natural flavoring has to come from a spice, fruit or fruit juice, vegetable or vegetable juice, edible yeast, herb, bark, bud, root, leaf or similar plant material, meat, seafood, poultry, eggs, dairy products, or fermentation products thereof, whose significant function in food is flavoring rather than nutritional.

CG: Good job.

NT: And artificial is something that doesnt come from any of those.

CG: So, like I said, the natural flavor in a strawberry yoghurt, it could be from a type of grass.

NT: Or a piece of wood. Thats one of the most common sources of vanillin wood pulp.

CG: Speaking of vanillin - we cant ignore everyones favorite source of vanillin: beaver butt. I mean, I know it isnt beaver butt exactly, its a chemical produced in a beavers anal gland. Thats a source of vanillin, too, as I understand it.

NT: It certainly is, and it would qualify as a natural flavor. Apparently beaver butts smell really nice.

CG: You ever smell one?

NT: Not me, thank god, but thats what naturalists have said. But its actually super unlikely that your vanilla flavor is being made from beaver butt secretions because milking beavers anal glands is slow work, and the resulting flavor would be wildly expensive.

CG: Hence the wood pulp.

NT: And actually a lot of vanillin is made from guiacol, which is a petrochemical. But, just to be totally clear, the vanillin from wood pulp, the vanillin from guiacol, and the vanillin from a beavers butt is exactly the same chemical. Exactly the same. Its just how you label it natural or artificial.

CG: So why would a food manufacturer choose one over the other, fake vanillin over natural vanillin?

NT: Yeah, so I decided it was time to actually talk to a flavorist. And I called Michelle Hagen, who is a senior flavorist at Givaudan.

CG: You heard her at the start of the episode, she was talking about root beer flowers.

NT: And she told me that the biggest factor in deciding between natural and artificial flavor is cost.So, for example, Michelle said that theres one particular chemical that flavorists add to graham crackers to get that signature grahamy flavor. Its $25 a pound when you extract it from plants. And its only $6 a pound made using the wonders of organic, carbon chemistry.

MH: Yeah, cost is the main driver for us. The only other thing is maybe purity. So a synthetic material is more pure. Because you do get some impurities when you have a naturally derived material.

CG: Then why bother using natural flavors at all? Are they more environmentally sustainable, or are they beneficial in any way?

NT: Well, Michelle says sometimes those impurities make the end result more interesting. So she kind of likes the challenge of working with naturals. Whether or not it is more environmentally sustainable varies by the chemical and how much processing you have to do to purify it from whatever youre starting with. But the real reason to work with naturals is because consumers want it.

MH: So I create mostly for the US beverage market, and I would say 99% of the time our customers, and their customers, which are the consumers, demand natural flavors. I haven't made an N&A flavor in four years.

NT: N&A, by the way, is industry shorthand for artificial flavors, because they have to be labeled natural and artificial flavors on the packet, n&a.

CG: OK, thats the difference between using natural and artificial flavors according to the legal definition. But theres another way of thinking about natural. Like a natural flavor is a flavor that is more like nature, right, its more true to life. And things have come a long way since the early 1900s. There are way more advanced scientific technologies to tease apart what chemicals are in any particular natural object. So are the flavors Michelle creates more complex than those one-note Skittles or that original pineapple flavored hard candy at the Crystal Palace? Is anyone getting closer to a real pineapple flavor made in a lab?

MH: I would say for an average flavor you are looking at 40 to 70 different ingredients.So for pineapples, for example, they are one of my favorite flavors to create. Theyre very complex. And they have nuances that are fruity, creamy, jammy, there is a floral nuance in pineapples. There is a greenness to pineapples. And there is even a woody aspect that kind of denotes that pulpiness. So they are really complex.So when we set out to create a pineapple flavor we have many challenges to hurdle. Is the flavor natural or artificial. Is it a liquid or a powder. We have to consider stability, solubility, cost. And then you go into the application, right? So is it in yogurt, is it in chewing gum, does that base have fat, does that base have protein?So we have to skew these pineapple profiles to taste delicious in every circumstance I mentioned.

NT: Wow so every pineapple is sort of a specific project depending on all of those factors. I mean you must've created thousands of pineapples then?

MH: Yeah I have hundreds. Within the company I know there are thousands, maybe even 10,000.

NT: So, yeah, to answer your question, Cynthia, science has definitely advanced and pineapple flavor tastes a lot more pineappley than it used to. But whats interesting about that is that we still arent making an exact, true to life, one to one copy of a real pineapples flavor. Our technology is amazing, we can find hundreds of aroma chemicals in fruit, but our noses are still better. So if you make a pineapple just based on what the machine says is in the pineapple, you wont capture everything that our palate expects. And thats where the art of the flavorist comes in.

Nadia actually described this essay in a 1950s Givaudan catalog. It was written by a flavor chemist just after the new technology was introduced, the tools to finally break down a food into its individual flavor components. Whats funny is that flavorists immediately realized they couldnt rely on the machine read out alone. So they built a special sniffer so that they could use their noses to sample the smells right alongside the machine. Apparently they used to get terrible nosebleeds from sniffing so much.

CG: Hazard of the job.

NT: But, even though this essay is 60 years old now, this description really captures how a flavorist has to use science *and* art, their own noses, to create, say, a strawberry flavor.

NB: What a flavor chemist does, in addition to working with this chemical analysis, he does this sensory analysis of the strawberry. So there is a bunch of different notes he says kind of working like a perfumer. So theres a fruity note, theres a note that he calls green butter. There is one that is sweet, one that is balsamic, one that he calls rose honey, fresh hay, and then this sour and citrus note. So basically you combine what you know about what is actually in strawberries and what you know about chemicals that have these sensory properties to create this sort of ideal version of the strawberry that is ineffably strawberry-like, that might be tweaked to suit the particular needs of your client.

NT: Michelle told me she still works the same way today. The machine is like a guide and a fact-checker, but her nose is the boss.

CG: But some things have changed in the flavor world. In fact we are at the beginning of a major shift right now - theres some brand new biology that is changing how we make flavors altogether.

NT: Its tied to what Michelle was telling us about not using artificial flavors in her work any more, just because consumers dont want them. Companies are trying to get what they call a clean label that means it doesnt use words like artificial or long chemical names that people cant pronounce. Because people think that those things are unhealthy. Whereas the word natural even if its the exact same chemical youre talking about, well that just sounds a lot better.

CG: And heres where yeast comes in. You may think that yeast is just useful for brewing beer or turning milk into delicious cheese.

NT: Which it is, as we discussed a couple of episodes ago.

CG: Of course. But yeast can do all sorts of other things, too. Scientists have figured out how to tweak yeast by introducing chunks of DNA, and those chunks are copied from animals or plants. And these new designer yeasts make all kinds of useful products. They make medicines like insulin and rennet to curdle our cheeses. You may have also heard of research into using algae to produce fuel for our cars. These are engineered microbes, too.

NT: Youre actually pretty much guaranteed to have eaten cheese made using rennet from this engineered yeast. The stat I have is that in 2008, ninety percent of cheeses in the US and the UK were made using rennet that had been produced by a genetically modified yeast.

CG: This whole field of redesigning organisms usually microbes like yeast to produce new outputs, its generally called synthetic biology. Now scientists are tweaking yeasts for a new product: flavor.

NT: We talked to Christina Agapakis, shes a synthetic biologist who just joined Gingko Bioworks. Theyre one of a handful of companies that are building these designer yeasts to produce flavor and fragrance chemicals. Heres how the process works.

CG: So lets say somebody asked you to design a microbe that was capable of producing a coconut flavor. How would that work can you take us through the steps?

CA: Sure. So I guess we would first start I looking at how coconuts makes labor. So when you look at the biology of coconuts and the enzymes that exist in coconuts that create all those different molecules that create the coconut flavor, what we would do is look at those genes that code for those enzymes. Try to understand them. And then make them in our foundry. And put them into a yeast and see how they work in the yeast. How can we kind of try to shape the yeast metabolism to be a little bit more like coconut metabolism. So we have the same enzymes that are producing the molecules and the great flavor of coconut inside of the yeast that we can then ferment and brew coconut flavor.It's basically as the microbe ferments as the yeast grows and is fermenting the sugars what they're doing is, they'll make alcohol or whatever the kind of typical byproduct of the fermentation. But as another byproduct you have the molecule that you want to be making. Whether it's the rose oil or vanilla extract or any kind of as theyre fermenting as theyre growing you're producing that molecule. so really it is like it's like brewing beer. And in a way flavored beer.

NT: Flavored beer is my least favorite kind of beer. But seriously this is a big step forward for science. Scientists have known how to transfer single genes from a plant or animal into another one, but this is different.

CA: What makes the ability to create flavors is the ability to do it with more genes. To understand how those genes work together. To be able to fit them all together in a more complex system. So to make a flavor you might need five or ten different enzymes that are creating a whole pathway and are really shifting the metabolism of the yeast. Whereas to make insulin its a single gene that makes a protein. And so that's a much simpler process biologically and one that simpler to do this kind of engineering approach.

NT: At Gingko, the first of these cultured flavors and fragrance chemicals that theyve announced is a rose oil for perfumers. They have other ones in the pipeline for the food industry. Meanwhile, theres Evolva, a Swiss company, theyve already put a yeast-fermented vanillin on the market. And a group in Austria just announced they have managed to engineer yeast to produce the key flavor chemical in grapefruit.

CG: But why are they all bothering to making these cultured flavors if we already have natural and synthetic ways to make, say, vanillin?

NT: I was curious about that too. So I a visited Gingko Bioworks they cal it their Foundry where they build the yeasts that are going to make the flavor. I talked to Patrick Boyle. Hes one of the founders there and his job title is Organism Designer.

PB: So what were interested in doing is, can we design a fermentation process so we can culture those ingredients instead and eliminate some of the harsh chemical steps, as well as kind of relieve some of the supply issues that come from using really rare plant to extract things from. And youd be surprised how much of that is involved with flavor. You know, you can kind of look at the kind of history of the spice trade and looking at how resource intensive that can be and how constraining that can be. Part of what we're interested in here is can cultured ingredients be a way to prevent us from really expanding unsustainable farming practices. So many many more exotic plants that flavors and fragrances are extracted from are hard to grow and hard to grow without using a lot of water.

CG: Christina also told us that because they can get the yeasts to produce a number of flavor enzymes, they can create a richer, more nuanced taste. Its got some of those impurities Michelle mentioned. Itll be closer to the real thing.

NT: More of the wide varieties of flavors you tasted in that real vanilla, versus the one-note vanillin. And in a weird way, it might actually democratize some of the worlds most expensive, rare flavors. Like saffron, for example. Having a yeast make saffron is a lot cheaper than collecting the stamens of thousands of tiny crocus flowers.

CG: I can only imagine. But lets say cultured vanillin becomes wildly popular. What does that mean for vanilla farmers in Madagascar and Mexico?

PB: The vanilla bean producers have been around for a very long time, and artificial vanilla has been on the market for a very long time. So I think it's clear that both industries can co-exist. If we could grow more vanilla bean we certainly would.

NT: So there are some sustainability benefits, maybe price benefits too. But the real attraction for companies looking to use these cultured flavors is that they are considered natural not artificial, for the purposes of labeling.

CG: Really? Even though they are made from genetically modified yeasts?

NT: Yes. The thing is theres no yeast left by the end of the process. They just do their job, make the flavor, and die. Like in brewing. Or like in all the genetically modified yeasts that make rennet that makes our cheese.

CG: I know Christina made the process sound simple - figure out which DNA the yeast need and insert the right bits. But of course science is not nearly that straightforward. She said this process takes a long time.

NT: Yeah. Gingko have been working on their first one, this rose oil, for more than a year at this point. Patrick told me the main issue is just yeast variations that dont work. That dont produce the flavor. Patrick and Christina test hundreds at a time, each with tiny differences in the DNA.

CA: The main kind of exciting thing that we can do at the foundry is really be able to test many different variants. So we wouldn't have just one and hope for the best. We would be able to test like okay if we little bit more of this gene and a little bit less of this gene, a little bit more of this enzyme, what's the final smell going to be like what's that flavor in the end.

NT: OK, so this episode is all about artificial flavors. And weve discovered that the line between artificial and natural flavors is actually kind of blurry. At least the way the FDA defines it. You can get natural strawberry flavor that is made using super intense harsh chemicals in a big industrial factory from ingredients that have never been anywhere near a strawberry in their lives. And these brand new designer yeast flavors are natural too. So I went looking for something that is a truly artificial flavor. In the industry, theyre called fantasy flavors.

MH: It's the reason I get out of bed. I love fantasy flavors. Okay, lets say apple. Everyone has an opinion on what a crisp apple should taste like, so it is carved in our brains since we crunched into an apple from our third grade lunch. But a fantasy flavor is sort of undiscovered and it has no boundaries. You can do anything you want, call it anything you want.So if you think about bellbottoms in the 70s if you translate that into a fantasy flavor think of Juicy Fruit. That is kind of fantasy flavor. You essentially have an orange flavor with this very large upfront isoamyl acetate, ethyl butyrate note.

NT: Isoamyl acetate, for those of you who dont have a chemical dictionary to hand, is that fake banana flavor we encountered earlier. And cast your mind back to the 350 flavors in a strawberry ethyl butyrate is one of them. Michelles point is that Juicy Fruit is a fantasy flavor. It takes something that people are familiar with orange and then adds these other notes you wouldnt expect to find in an orange to transform it into something new. Another example is Red Bull.

MH: So its something that is kind of familiar, like black cherry, and then you add this very large medicinal guarana flavor and then you have got Red Bull.So one way of looking at it is something that is kind of known, you put a spin on it, you add a zinger. You kind of move it into an uncultivated space. In our world we call that the white space. Doing something that no one has ever done before.

NT: That expression white space. I love it. Theres an infinite number of fantasy flavors still waiting to be created. Its expanding flavor-space in our minds.

CG: Theres all the fantasy flavors, sure, but there are also extinct flavors too. All those plants weve lost, the original ancestors of the grains and fruits and vegetables that we eat today.

NT: Yeah, and Christina, at Gingko - she thinks that might actually be possible using this new science.

CA: The science behind trying to understand extinct flavors. There's the kind of Jurrasic Park fantasy, you can find may be embedded in amber you'll find some plant tissue and then you can extract the DNA. That's possible perhaps. But maybe not from actually the Jurassic. But maybe a few thousand years ago.But there's also ways that we can use evolutionary biology, collaborate with evolutionary biologists to think about looking at plants that exist now, close relatives of things that may have gone extinct. You could reconstruct a lot of the biology and the genetics of the lost plants and try to work from there. That's what I'm thinking about, but I dont know if it's possible. And that can happen in the future that something am excited about.

NT: Its amazing, when you start thinking as well when our ancient ancient ancestors were figuring out farming, what they would have tasted when they sort of first began domesticating those foods. Because so many things are unrecognizable now. And yeah, we have the wild relatives but sort of getting back to you know you could imagine a bread course that gave you the taste of wheat over time.

CA: Wow.

NT: I'm having fun with this.

CG: I can imagine, how was it pronounced, teosinte - the original relative of corn you know what it was like when they first started breeding and creating big corn kernels to water so much what reading now but that tasted like.

CA: I love that, I'm taking notes.

NT: We will come to the first ancient wheat tasting.

CG: As weve learned over the course of this episode, artificial flavors started off as a vehicle for this new explosion of sugar. They almost helped smuggle more sugar into our diets. And then the flavors became crucial in our new industrialized food system. Processed foods shipped long distances needed those flavors added back in.

NT: And those flavors could have been either natural or artificial. In fact, in a lot of ways, artificial versus natural doesnt really matter. Theyre the same chemical, made in the same factories, just from different source materials. The bigger story is that over the past 100, 150 years, the flavors that are naturally in our fruit, veggies, meat have become blander. Meanwhile, our diets, at least in rich countries, have overall become more flavorful but a lot of that flavor is coming from added flavors. The story of inventing artificial flavors and how weve used them, its kind of this parallel track to the story of where our food system went wrong. At the same time we were robbing our apples of any flavor hello, Red Delicious apples we were making Doritos Locos Explosion Flavor crazy bomb.

CG: But today there are new uses for these flavors. Like helping insect or pea protein - both of those seem to be pretty sustainable sources of protein that some people dont like the taste of them necessary, so these flavors could help them become more tasty and easy to integrate into our daily diets.

NT: So its less that artificial flavor is bad and natural flavor is good, or even that all added flavor is necessarily bad or good. Its all in about we use it. And whats fascinating is that when you look at the flavor business, it can tell us a lot about our relationship with food. Thats why Nadia is studying this, really.

NB: When you are creating a synthetic strawberry flavor, a synthetic peach flavor, in a certain way of thinking about it, youre replicating the sensory qualities of the natural world. Youre looking out there and you are saying that this is what these things are like. And we are going to figure out a way to reproduce this chemically. On the other hand what youre doing is youre replicating people's desires, people's appetites. Which are not necessarily always completely coherent with what is actually possible naturally. So I think that the really skilled flavor chemists and flavorists have this sense of all of the effective qualities that we expect from actual foods and flavors.That we are not just looking for a strawberry that resembles a strawberry or a cherry that resembles a cherry. Theyre looking for something that replicates our desires, our memories, the field of association we have when we think of refreshment or summer or sweetness or nature itself. You're producing a synthetic version of our expectations of what it means to consume nature.

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CG: Thats it for the world of artificial flavor. Come back in two weeks and youll hear me visit the first American escargot farm. Thats snails. Actually, thats gastropods.

NT: The actual kind, not the podcast kind.

CG: To help us explore the weird and wonderful world of artificial flavors we had a lot of help. We couldnt have done it without Christina Agapakis and Patrick Boyle of Gingko Bioworks.

NT: Side note, Christina recently launched an online magazine called Method which is all about how scientists actually do science as opposed to the way it gets written up and smoothed out once the results of an experiment are in. I think you all would find it pretty interesting.Its a perspective thats missing from the mainstream media. Links on our website. Thanks also to Nadia Berenstein, and to Michelle Hagen of Givaudan. We have links to their work and more about what they do online too. Check them out.

CG: There are lots of goodies in our episode notes this week. Including one of my favorites, a history of Manischevitz wine and the Concord grape.

NT: As always, you should get in touch and tell us what you thought. But please also get in touch with your cocktail stories. And, if you or your company wants to sponsor an episode, well, then we really want hear from you.

CG: You can always reach us at contact at gastropod dot com. You can follow us on Twitter at gastropodcast, find us on Facebook, and give us lots of stars on iTunes.

NT: Yes please! And thats it from us. Til next time.

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