Everything I Thought I Knew About Flavor Was Wrong

0:00 Thank you to AnyDesk for supporting PBS.

0:03 (chips crunching) You're hearing the crunch as I eat these delicious chips.

0:11 But here's what I'm hearing

0:12 through my headphones when I take a bite.

0:15 (gloppy liquid sloshing) This is the grossest experience of my life.

0:20 (gloppy liquid sloshing) Oh, that was the worst chip I've ever eaten.

0:25 Nothing was wrong with it

0:26 except that I heard it make a gross sound

0:29 and that totally messed up its flavor.

0:31 But how can a sense like hearing

0:33 mess with how we perceive flavor?

0:35 Maybe you and I have been thinking about flavor all wrong

0:38 because it turns out it's way more complex

0:41 than just how something tastes and smells.

0:43 So what does flavor really mean?

0:45 How many senses does it actually involve,

0:48 and why is it so tied

0:50 to things like memories from childhood?

0:53 Today we're visiting a flavor manufacturer to meet one

0:55 of the world's top flavorists,

0:57 and I'm gonna fool my brain into smelling

1:00 and tasting things that aren't even there.

1:02 This is the science of flavor.

1:05 (light playful music) We're at a flavor laboratory in Austin, Texas

1:13 to ask, what is flavor anyway?

1:17 I mean, there's smell, there's taste,

1:20 like, there's crunchiness.

1:22 It's like the feel of things like your memory

1:24 and like, I don't know.

1:25 So this is like the pro sports

1:27 of flavor right here.

1:28 Yeah.

1:29 You're like in the NFL.

1:30 There's less of us than pilots.

1:32 Let's test you and see how good your nose is.

1:36 We're gonna test some raw materials

1:38 and they're for our characterizes, for our flavors.

1:42 We have different notes that happen within a flavor,

1:46 but these are the ones

1:47 that are really going to drive it home what it is.

1:49 So this is like the core fingerprints

1:51 of the flavor.

1:51 This is like-- The identity.

1:53 Quintessential.

1:54 Okay.

1:55 First one.

1:59 Wait.

1:59 Oh, this one I know.

2:01 Okay.

2:02 This tastes like, like baking almond extract.

2:04 This is actually kind of a trick

2:07 because it can be used in almonds and cherries.

2:10 It's very, yeah-- As soon as she said that,

2:12 it's like maraschino cherries.

2:13 I saw that mind explosion.

2:13 It has like that artificial cherry notes.

2:16 Those red cherries that go on top of ice cream.

2:18 Yeah, the maraschino cherries.

2:19 That's amazing.

2:20 How many people on Earth have your flavor certification?

2:25 I am certified through the Society of Flavor Chemists.

2:27 There's about 500 of us.

2:29 You have to not only gain employment with a flavor house,

2:34 but they have to have a certified flavorist

2:36 who agrees to train you.

2:38 You're just like studying

2:39 flavors all the time.

2:40 All the time for seven years.

2:42 Just smelling everything you can get your hands on.

2:45 Yes.

2:46 So you're now like a walking, talking

2:48 encyclopedia of flavor.

2:51 I hope so.

2:52 Okay.

2:52 You ready?

2:53 I think so.

2:54 Famous last words.

2:56 Okay.

2:56 (waves lapping) This is very banana-y.

3:00 I'm getting a lot of, this is a tropical,

3:03 but I feel like there's a trick.

3:04 It can't just be banana, right?

3:05 It is banana.

3:06 It is just banana?

3:06 It is just banana.

3:07 Okay.

3:08 And it's interesting that you said tropical

3:10 because it can go in tropical stuff too.

3:12 It's not just bananas.

3:14 Even if it's not literally banana-flavored.

3:16 It can be a secondary player for something else

3:18 and maybe not the primary.

3:20 And so it's just different amounts of paint

3:22 that you're using for your picture.

3:24 Okay, we're moving to savory.

3:25 (liquid simmering) This is a funky one.

3:29 Cooked vegetables, like soup base,

3:31 like carrots and celery and stuff.

3:33 But kind of porky.

3:34 I get the pork in there now that you say it.

3:36 It's a tonkatsu ramen.

3:38 How do you make something porky?

3:39 Like what?

3:40 What does porky even mean chemically?

3:42 There's more paints.

3:44 And that's what this particular flavorist did

3:46 was build that realism that goes with it

3:50 to give you that illusion

3:53 that you're having tonkatsu ramen.

3:56 (light playful music)- It's garlic, onion.

3:59 It's like french onion soup.

4:01 It's a brown note.

4:02 You're learning.

4:03 If this doesn't work out, you know.

4:05 (laughs) And last one.

4:09 Ooh, roast beef.

4:10 It is beef.

4:12 After experiencing some truly mind-blowing flavors

4:14 in the lab, I have to ask Lauren, what is a flavor anyway?

4:18 Basically, a flavor is aroma materials in a solvent

4:22 that imparts aroma in taste with no nutritional value.

4:27 But a lot of emotional value.

4:29 There you go.

4:30 When we taste something,

4:31 we're experiencing the molecules it's made of,

4:34 those aroma materials.

4:37 If the innate properties of molecules

4:39 were all there was to a flavor,

4:41 Lauren's job would be way easier.

4:43 But these molecules have to be perceived

4:45 by our weird, messy bodies.

4:49 And that makes things way more complicated.

4:51 You might not expect it,

4:53 but eating these chips

4:54 is gonna activate nearly every sensory system in my body.

4:58 Let's start with taste perception, also known as gustation.

5:03 (chip crunching) The little bumps on our tongue called papillae,

5:08 each contain a bunch of taste buds.

5:10 Each taste bud is home to a cluster of receptor cells,

5:13 and each receptor cell responds to a different taste.

5:16 We have receptors for sweet, salty, sour, bitter, umami,

5:21 and possibly even fat as well.

5:23 All these receptor types

5:24 are found in taste buds all over the tongue.

5:26 They are not arranged in distinct little regions

5:29 like that ubiquitous tongue taste map suggests.

5:33 I repeat, this map is a myth, it has been debunked.

5:37 Experts are literally begging us

5:39 to stop talking about the tongue taste map.

5:42 Please stop talking about the tongue taste map.

5:44 As I eat this chip,

5:45 I'm tasting some saltiness, savoriness, a little acidity.

5:49 Each of those receptors in my tongue is getting triggered

5:51 by a different chemical component in my food.

5:53 The salt receptors are responding to dissolved sodium ions,

5:56 the umami receptors to an amino acid called L-glutamate,

6:00 and the sour receptors to dissolved hydrogen ions,

6:03 basically the pH of the chip.

6:05 But just how good am I at tasting stuff like chips?

6:09 Well, there's actually a test for that.

6:11 This is our next test to see if Joe's a super taster.

6:15 I really want to be a super taster.

6:16 You've been itching to know your whole life

6:18 if you're a super taster and now is the moment.

6:21 I'm not gonna be disappointed if I'm not, okay?

6:22 The paper strip contains a bitter tasting chemical,

6:25 but different people have more or fewer receptors

6:27 in their tongue for that bitter chemical.

6:29 The strength of my reaction will tell me

6:31 if I'm a non-taster with no receptors for that chemical,

6:34 an average taster, or a super taster.

6:37 Okay, here it goes.

6:39 Ready?

6:41 Hmm-mm (mumbles).

6:42 Is it super offensive?

6:44 It's not good.

6:45 This is a great way to talk.

6:46 I would say you're a moderate taster.

6:47 You can detect that it's there,

6:48 but you're not pulling it off of your tongue.

6:51 If you were a super taster, it'd be like overpowering?

6:53 So whenever I think about tasting this,

6:55 I get goosebumps because I hate it so much.

6:59 The fact that you can put it back on your tongue

7:01 is alarming.

7:02 Okay.

7:02 So I'm not a super taster.

7:04 I don't think you're a super taster,

7:05 but you can taste well.

7:07 Okay, but I'm not a non-taster.

7:09 You're not a non-taster.

7:10 Super tasters tongues also have denser taste receptors than non-tasters.

7:14 In fact, individual variation in receptor density

7:17 is way higher for taste than for any other sense.

7:20 These little bumps on our tongue

7:22 have the power to make us experience the exact same food

7:25 completely differently from another person.

7:27 Whoa!

7:28 Does that mean that like my nacho cheese chip

7:32 is different from your nacho cheese chip?

7:34 (train steam hissing) Now let's move on to smell perception,

7:37 also known as olfaction.

7:39 Now, who you think would win in a flavor fight?

7:42 Olfaction or gustation?

7:44 Well, let's do a little experiment.

7:45 I'm gonna try to tell the difference

7:47 between foods with similar textures

7:49 while blindfolded and holding my nose.

7:52 My olfaction will be completely cut off,

7:54 but my gustation will work just fine.

7:56 Which one should I go for first?

7:58 This one?

7:59 I think I'll do this one first.

8:00 (chip crunching) Crunchy.

8:02 Literally just clunks, I have no taste.

8:05 Okay.

8:08 All I have is sweet.

8:10 There's nothing else happening.

8:12 Is this the third one?

8:16 This is also just crunchy and sweet.

8:18 Those are different?

8:19 'Cause they're just sweet and crunchy.

8:21 I don't know what this was.

8:23 This had no flavor at all.

8:24 (blows raspberry) These two, they're just sweet.

8:28 I think this is apple and this is pear.

8:31 I'm gonna reveal.

8:33 What?

8:34 This was apple?

8:35 This was pear?

8:36 I would totally have guessed otherwise.

8:40 I was wrong.

8:41 So that test shows us olfaction

8:42 is the real hero of flavor perception.

8:45 It's the dominant sense over gustation.

8:48 So there are actually two types of olfaction.

8:50 If I sniff this chip

8:52 and perceive that distinct cheesiness,

8:54 that's orthonasal olfaction, the scent particles are traveling up my nose.

8:59 But if I eat this chip and perceive its cheesiness,

9:02 that's retronasal olfaction.

9:04 The scent particles are traveling up

9:06 the back of my throat into my nose.

9:08 Retronasal olfaction is what's responsible

9:11 for most of flavor perception.

9:13 The destination of those scent particles

9:14 is the olfactory epithelium,

9:16 a patch of millions of olfactory receptor neurons

9:20 embedded in your nasal cavity.

9:22 One end of those receptors is exposed to air,

9:25 no other neurons in our body do this.

9:28 A scent molecule needs to be the right shape

9:30 to fit its corresponding receptor.

9:32 But that means we need so many different receptor types

9:35 to smell all the smells out there.

9:37 We actually have more genes for olfactory receptors

9:39 than any other type of gene in our genome.

9:42 We have about 350 receptor types that work in combination

9:46 to allow us to detect roughly 10,000 or so smells.

9:50 But about 1/2 of our olfactory receptor genes

9:53 are no longer functional,

9:54 meaning that our ancestors

9:56 could likely discern a much broader bouquet of scents.

9:59 Kinda makes you wonder,

10:00 what would Homo heidelbergensis have thought about these?

10:04 Probably would've loved them.

10:05 Once our olfactory receptor neurons fire,

10:07 they send signals to the olfactory bulb of the brain,

10:10 which is right about here-ish,

10:13 which then transmits them directly

10:14 to the olfactory cortex for processing,

10:16 which is right about, you know what?

10:20 Bring up the diagram.

10:21 After the olfactory cortex,

10:22 smell information goes to the amygdala,

10:24 a key brain region for processing emotions

10:26 and the hippocampus, which is critical for processing memories.

10:30 This is a super different signaling pathway

10:32 than any of our other senses.

10:34 Taste, vision, hearing, and touch signals,

10:37 they all take completely different paths

10:38 before heading to memory processing.

10:40 Because flavor signals pass through those emotion

10:43 and memory centers of our brain

10:45 is precisely why flavor evokes such strong emotions

10:49 and memories compared to other senses.

10:52 Taste and smell are crucial to flavor, obviously,

10:55 but we can't ignore hearing,

10:57 which until recently was the forgotten sense

10:59 in flavor research.

11:00 These days, flavor scientists have come up with an equation

11:03 for the perfect bacon crunch in a BLT.

11:06 They've defined the ideal frequency ranges

11:09 for crispy and crunchy food noises.

11:11 It's these, by the way.

11:13 Scientists have even studied

11:14 how sounds impact our overall perception of flavor.

11:18 Like what happens if you hear a squish

11:21 while you're expecting a crunch.

11:22 But hearings influence on flavor

11:24 can be even more subtle than that.

11:26 In one study, participants rated chips

11:28 as being more stale if a lower frequency crunch

11:32 was played in their headphones while they ate it.

11:34 There are other flavor senses too.

11:37 There's also somatosensory perception,

11:39 which gives us a lot of information

11:41 about what we're putting in our mouths.

11:43 We're talking touch receptors that detect texture,

11:46 mouth feel, even fizziness.

11:48 Thermoreceptors that let us know

11:50 how hot or cold something is,

11:52 and pain receptors that can tell you how spicy a chip is.

11:56 The somatosensory system interacts

11:58 with our other senses to impact how we perceive flavor.

12:02 Sweet things feel more viscous.

12:04 Warm food tastes more flavorful.

12:07 Spiciness decreases our sensitivity to other flavors.

12:11 Finally, we also have to talk about vision.

12:14 It impacts our anticipation of food.

12:17 And this is important because that triggers

12:19 our autonomic nervous system,

12:21 which turns on our salivary glands to get ready to eat,

12:25 but it also impacts our perception of flavor

12:28 and scientists are having way too much fun

12:30 figuring that out.

12:31 They have served wrong-colored foods at dinner parties

12:34 and then watched all the guests all start to feel ill,

12:37 even though the food was totally fine.

12:39 They trick sommeliers into thinking white wines are reds

12:42 just by adding food coloring

12:44 and they mess with the lighting to turn food weird colors.

12:49 Oops, sorry.

12:50 And beyond our senses,

12:51 I mean, things like language and culture

12:53 can even influence flavor.

12:54 If you tell someone a certain smell is coming from cheese,

12:59 they'll have a different reaction to it

13:00 than if you say that smell is coming from sweaty feet,

13:03 even when it's the same smell molecules coming from each.

13:07 Studies of cultural impact

13:08 on flavor perception are fascinating.

13:11 In one example, American study participants

13:13 experience heightened almond olfaction

13:16 when holding a sugar solution in their mouth

13:19 while Japanese participants experience heightened almond olfaction

13:22 when holding an umami MSG solution in their mouth.

13:25 Researchers think it's because

13:27 we have different cultural associations

13:29 about whether something like almond

13:31 should be sweet or savory.

13:32 So yeah, master flavorists have their work cut out for them.

13:37 They have to juggle our senses,

13:39 our very unpredictable interactions,

13:41 and their cultural and linguistic contexts

13:45 all to create a delicious perception in our brain.

13:49 Let's see how this all comes together in the lab.

13:52 When you're actually making a flavor,

13:55 what does it mean to make a well-balanced flavor

13:58 that's a good experience for somebody?

14:00 A well-balanced flavor has to have a front,

14:03 a middle, and an end.

14:04 It's a story that has a great beginning,

14:07 gets your attention, has really great middle notes,

14:10 and finishes off with like a bang basically.

14:12 And that's what we're gonna do here.

14:14 So these are like the individual components.

14:17 Yes.

14:17 And then at the end of this,

14:18 you can tell me what you think the flavor we built is.

14:21 Okay, so this is the first one.

14:24 This is an ester.

14:26 Yeah, it's like a sharp, like it's a chemical fruitiness.

14:29 Different chemical classes have different weights,

14:32 different makeups that allow it to come across in different times.

14:36 So an ester is gonna come in the beginning.

14:38 This is a lactone.

14:40 So this is heavier.

14:42 It is, is earthier.

14:44 Yeah, it's like lower.

14:45 It's like a base note.

14:47 A lactone usually is creamy, fruity.

14:50 Creamy, I get that, yeah.

14:52 And then those two together,

14:53 that's yeah, you can tell, like, one,

14:54 yeah, it's hitting in different parts of my skull.

14:56 This is so fun!

14:57 Okay, hit me with the next one.

14:59 This is an alcohol.

15:01 So this is gonna be one of our front guys as well.

15:04 Oh yeah, very alcoholic.

15:06 Woo!

15:07 It's not quite what mowing the lawn smells like,

15:09 but it's definitely that like wet,

15:11 like, crushed up like leaves grassy kind of thing.

15:15 So the green will add some unripened notes.

15:17 Unripened, I like that.

15:18 I'm glad you're here to give the good words.

15:21 No, you're doing a really great job.

15:22 Okay, so this one is a ketone.

15:26 Ooh, I'm getting candy.

15:27 And it gives like a perception of cooked.

15:28 It's like cooked sugar.

15:30 Yeah, it's perfect.

15:31 Obviously we're making a fruit, right?

15:32 It's telling you, okay, you have those unripe notes

15:36 because fruits can be unripe

15:37 and you have a little bit of those cooked notes

15:39 because as they age, they do create sugars.

15:42 The weirdest game of carbs I've ever played right here.

15:45 [Lauren] So this is another ketone.

15:46 This is actually one of my favorites.

15:48 This one's very sharp, like pointy.

15:50 [Lauren] It's seedy.

15:51 It's like those strawberries

15:52 you get in the pack that are not quite ready to eat.

15:54 Yes, so put that with your group and smell that.

15:57 Isn't it crazy how it's getting more-- Wow!

15:59 And more complex as it's going?

16:01 Yes!

16:01 And we're not even done yet.

16:02 You can feel them, like.

16:04 [Lauren] But they're all working together.

16:05 They're basically singing kumbaya right now.

16:07 Yeah, they are.

16:08 We have a great choir coming in, okay.

16:10 [Lauren] Okay, so sniff lightly, this is an acid,

16:12 so it's another one of our front guys.

16:15 Okay.

16:15 Yeah, that's a little, that's a little funky.

16:17 Very sharp, cheesy, like, there's some aging going on here.

16:20 Like, if I was in fruitville,

16:22 I'd be like, this is not, that one's going back.

16:24 [Lauren] On its own, yes.

16:25 I mean, it's weird, once you put it with the other ones,

16:27 yeah, it like fills out this flavor-- And it brightens it, it lifts it.

16:32 And now that strawberry just became like somehow riper.

16:36 Yes.

16:36 Like fuller in this.

16:38 More realistic.

16:39 What the heck is going on?

16:41 Brains are weird.

16:42 [Lauren] Okay, last one.

16:44 This is a sulfur.

16:45 What does it smell like?

16:46 Rotting is what it smells like.

16:47 It just smells like-- It smells like canned corn.

16:50 Oh my God, it does.

16:51 (both laughing) I get these all together.

16:55 (light tropical music) Oh, this is wild.

16:58 I'm holding a strawberry,

16:59 like, every piece of the strawberry.

17:01 You don't wanna get any one of them too strong.

17:03 There's like ripeness and like almost like fermented

17:07 like vinegary notes in there.

17:08 It's like the whole life of a fruit going on here.

17:11 And the leafy green.

17:13 Yeah.

17:14 The juiciness of it.

17:15 All right, new YouTube feature needed: Smell o vision.

17:18 This is like-- It's witchcraft.

17:21 You're like Willy Wonka.

17:22 Oh, thank you.

17:23 Yeah, this is amazing.

17:24 This has just been such a mind-blowing experience.

17:26 You can tell my brain's kind of melting.

17:28 You're in the matrix right now.

17:30 (laughs) You are tasting these flavors,

17:33 even if it's not that actual strawberry,

17:36 it is the flavor of a strawberry

17:38 and the way that your mind connects it

17:40 to make it real to you.

17:42 It's important to know

17:43 that it is a valid thing to be tasting.

17:46 And even though it is concocted by, you know,

17:49 flavors and everything, it is what a strawberry would be in nature,

17:55 just not from the direct strawberry.

17:57 The brain doesn't lie, people,

17:59 if it thinks strawberry, then it's strawberry.

18:02 There you go.

18:03 Not only are you creating a flavor that tastes good,

18:06 but you're also evoking a memory for somebody.

18:09 Because there's so many other things

18:10 that go into that experience, right?

18:12 We've all had like a meal that just tastes so perfect

18:15 because of like the people you're with.

18:17 Or where you are.

18:18 Yes.

18:18 It could could have been your grandmother's last time

18:20 to create a lasagna for you.

18:22 Or ice cream cone that, you know,

18:25 you and your best friend had whenever you were five.

18:27 People are tasting it, they're seeing it.

18:31 They can pick up like those notes that we talked about,

18:34 but then it triggers something

18:35 and it makes it even more special to them

18:38 that they're having that with the flavor itself.

18:41 If I can bottle one feeling,

18:45 probably just happiness because the flavor should make you feel happy

18:48 whenever you're enjoying it.

18:50 We try to make the world taste better.

18:52 I thought consulting a flavorist

18:54 might reveal some singular truth

18:57 about the definition of flavor,

18:59 but instead I'm kind of wondering

19:01 whether flavor's even real.

19:03 I mean, even experts don't agree on exactly what it is,

19:07 but it's as clear as the crunchiness of a delicious chip

19:11 that the way we perceive flavor

19:14 is a symphony of many senses,

19:17 way beyond just taste and smell

19:19 carefully orchestrated by our brain

19:22 and even etched into our memories.

19:24 It's a deliciously complicated lens

19:26 through which we experience the world.

19:28 And now I can eat chips again

19:31 without it being a science experiment.

19:33 Stay curious.

19:35 (chip crunching) And thank you to AnyDesk for supporting PBS.

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20:54 We need more shoots with food.

20:55 This is good.

20:57 It's snack time.

20:58 Hey, welcome to Joe Reviews Chips.

21:01 [Speaker] Keep the teleprompter still.