The Science Behind Why We Crave Loud and Crunchy Foods

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A number of years ago, food giant Unilever polled consumers asking how the company might improve their popular line of Magnum ice cream bars. The problem, respondents said, was that the chocolate coating of the bars tended to fall off too quickly, creating blotches of sticky goo on carpeting. Unilever reacted by changing the recipe to make the chocolate less prone to spills.

When they tested the new and improved product, they expected a warm reception. Instead, they got more complaints than before. While the updated bar didn’t make a mess, it also didn’t make the distinctive crackle that its fans had grown accustomed to. Deprived of hearing the coating collapse and crumble, the experience of eating the ice cream was fundamentally changed. And not for the better.

Smell and taste researcher Alan Hirsch, M.D. refers to it as the “music of mastication,” an auditory accompaniment to the sensory stimulus of eating. “For non-gustatory, non-olfactory stimulation, people prefer crunchiness,” he tells Mental Floss. Humans love crunchy, noisy snacks, that loud rattling that travels to our inner ear via air and bone conduction and helps us identify what it is we’re consuming. Depending on the snack, the noise can reach 63 decibels. (Normal conversations are around 60 dB; rustling leaves, 20 dB.)

When we hear it, we eat more. When we don’t—as in the case of Magnum bars, or a soggy, muted potato chip—we resort to other senses, looking at our food with doubt or sniffing it for signs of expiration. Psychologically, our lust for crispy sustenance is baked in. But why is it so satisfying to create a cacophony of crunch? And if we love it so much, why do some of us actually grow agitated and even aggressive when we hear someone loudly chomping away? It turns out there’s a lot more to eating with our ears than you might have heard.

 
 

The science of crunch has long intrigued Charles Spence, Ph.D., a gastrophysicist and professor of experimental psychology and head of the Crossmodal Research Laboratory at the University of Oxford. Food companies have enlisted him and consulted his research across the spectrum of ingestion, from packaging to shapes to the sound chips make rustling around in grocery carts.

“We’re not born liking noisy foods,” he tells Mental Floss. “Noise doesn’t give a benefit in terms of nutrition. But we don’t like soggy crisps even if they taste the same. Missing the sound is important.”

In 2003, Spence decided to investigate the sonic appeal of chips in a formal setting. To keep a semblance of control, he selected Pringles, which are baked uniformly—a single Pringle doesn't offer any significant difference in size, thickness, or crunch from another. He asked 20 research subjects to bite into 180 Pringles (about two cans) while seated in a soundproof booth in front of a microphone. The sound of their crunching was looped back into a pair of headphones.

After consuming the cans, they were asked if they perceived any difference in freshness or crispness from one Pringle to another. What they didn’t know was that Spence had been playing with the feedback in their headphones, raising or lowering the volume of their noisy crunching [PDF]. At loud volumes, the chips were reported to be fresher; chips ingested while listening at low volume were thought to have been sitting out longer and seemed softer. The duplicitous sounds resulted in a radical difference in chip perception. It may have been a small study, but in the virtually non-existent field of sonic chip research, it was groundbreaking.

A view inside a potato chip bag
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For Spence, the results speak to what he considers the inherent appeal of crunchy foods. “Noisy foods correlate with freshness,” he says. “The fresher the produce, like apples, celery, or lettuce, the more vitamins and nutrients it’s retained. It’s telling us what’s in the food.”

Naturally, this signal becomes slightly misguided when it reinforces the quality of a potato chip, a processed slab of empty calories. But Spence has a theory on this, too: “The brain likes fat in food, but it’s not so good at detecting it through our mouths. Noisy foods are certainly fattier on average.”

Fatty or fresh, raising decibels while eating may also have roots in less appetizing behaviors. For our ancestors who ate insects, the crunch of a hard-bodied cricket symbolized nourishment. In a primal way, violently mincing food with our teeth could also be a way to vent and dilute aggression. “There are some psychoanalytic theories related to crunchiness and aggressive behavior,” Hirsch says. “When you bite into ice or potato chips, you’re sublimating that in a healthy way.”

 
 

All of these factors explain why crunch appeals to us. But is it actually affecting what we taste?

Yes—but maybe not the way you’d think. “Sound affects the experience of food,” Spence says. “The noise draws attention to the mouth in the way something silent does not. If you’re eating pâté, your attention can drift elsewhere, to a television or to a dining companion. But a crunch will draw your attention to what you’re eating, making you concentrate on it. Noisy foods make you think about them.”

That crunch can also influence how much food we consume. Because noisy foods tend to be fatty, Spence says, they’ll retain their flavor longer. And because the noise reinforces our idea of what we’re eating, it affords us a sense of security that allows us to keep consuming without having to look at our snack—not so important in a brightly-lit room, but crucial if we’re in a dark movie theater. “It becomes more important when you can’t see what you’re eating,” Spence says.

Thanks to this hard-wired feedback, the snack industry has made it a priority to emphasize the sounds of their foods in both development and marketing. In the 1980s, Frito-Lay funded extensive work at a Dallas plant that involved $40,000 chewing simulators. There, they discovered the ideal breaking point for a chip was four pounds per square inch (PSI), just a fraction of what we might need to tear into a steak (150 to 200 PSI). The quality and consistency of the potatoes themselves is also key, according to Herbert Stone, Ph.D., a food scientist who has worked with companies on product development. “Too thick, too hard, and people don’t like them,” Stone tells Mental Floss. “Too thin and they just crumble.”

The right potato sliced at the right thickness with the right oil at the right temperature results in a solid chip—one resilient enough to make for a satisfying break when it hits your molars, but vanishing so quickly that your brain and body haven’t even processed the calories you’ve just taken in. “If they pick it up and put it in the mouth and the crunch is not what they expect, they might put it down,” Stone says. “It’s about expectation.”

A shopper examines a bag of potato chips
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Walk down the snack aisle in your local supermarket or glance at commercials and you’ll find no shortage of claims about products being the boldest, crunchiest chip available. For years, Frito-Lay marketed Cheetos as “the cheese that goes crunch!” Even cereals try to capitalize on the fervor, making mascots—Snap, Crackle, and Pop—out of the sound their Rice Krispies make when submerged in milk. One ad for a brand of crisps drew attention for “cracking” the viewer’s television screen.

For most consumers, the promise of sonic flavor will draw their attention. But for a small number of people diagnosed with a condition dubbed misophonia, the sound of a co-worker or partner crunching on chips isn’t at all pleasurable. It’s insufferable.

 
 

According to Connecticut audiologist Natan Bauman, M.D., the average noise level of someone masticating a potato chip is between 25 to 35 decibels. (Other sources peg it as closer to 63 dB when you're chewing on a chip with your mouth open, or 55 dB with your lips closed.) When you hear your own chewing, the sound is being conducted both via the air and your own bones, giving it a distinctively unique sound. (Like talking, hearing yourself chewing on a recording might be troubling.)

For someone suffering from misophonia, or the literal hatred of specific sounds, it's not their own chomping that's the problem. It's everyone else's.

When we chew, Bauman says, the auditory cortical and limbic system areas of our brain are lighting up, getting information about freshness and texture. But people with misophonia aren’t struggling with their own sounds. Instead, they're affected by others typing, clicking pens, or, more often, chewing. The sound of someone snacking is routed from the cochlea, or cavity in the inner ear, and becomes an electric signal that winds up in the brain’s amygdala, which processes fear and pleasure. That's true for everyone, but in misophonics, it lands with a thud. They’ve likely developed a trigger, or negative association, with the sounds stemming from an incident in childhood.

“If you are scolded by a parent and they happen to be eating, or smacking, it becomes negative reinforcement,” Bauman says. Chewing, lip smacking, and even breathing become intolerable for sufferers, who often feel agitated and nervous, with corresponding increases in heart rate. Some fly into a rage.

Misophonics don’t necessarily recoil at all of these sounds all of the time: It may depend on who’s doing the snacking. Often, it’s a co-worker, spouse, or family member munching away that prompts a response. Fearing they’ll damage that relationship, sufferers tend to vent online. The misophonia subreddit is home to threads with titles like “And the popcorn eater sits RIGHT next to me on the plane” and “Chips can go f-ck themselves.” (The entire content of the latter: “F-ck chips, man. That is all.”)

Bauman says misophonia can be treated using cognitive therapy. An earpiece can provide white noise to reduce trigger sounds while sufferers try to retrain their brain to tolerate the noises. But even the sight of a bag of chips can be enough to send them scrambling.

People with misophonia might also want to exercise caution when traveling. Although some Asian cultures minimize crunchy snacks because loud snacking is considered impolite, other parts of the world can produce noisier mealtimes. “In parts of Asia, you show appreciation for food by slurping,” Spence says. Slurping is even associated with a more intense flavor experience, particularly when it’s in the setting of a comparatively quiet dining establishment.

Western culture favors noisier restaurants, and there’s a good reason for that. Supposedly Hard Rock Café has mastered the art of playing loud and fast music, resulting in patrons who talked less, ate faster, and left more quickly, allowing operators to turn over tables more times in an evening.

Spence believes sound will continue to be important to gastronomy, to chefs, and to food companies looking to sell consumers on a complete experience. Snack shelves are now full of air-puffed offerings like 3-D Doritos and Pop Chips that create pillows of taste. With less volume, you’ll snack more and crunch for longer periods.

A woman snacks on a chip
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But the sound of the chip is just one part of the equation. The way a bag feels when you pick it up at the store, the aroma that wafts out when you first open the bag, the concentration of flavor from the granules of seasoning on your fingers—it’s all very carefully conducted to appeal to our preferences.

“When we hear the rattle of crisps, it may encourage people to start salivating, like Pavlov’s dogs,” Spence says, referring to the Russian scientist who trained his canines to salivate when he made a certain sound. We’re conditioned to anticipate the flavor and enjoyment of chips as soon as we pick up a package. Even hearing or saying the words crispy and crunchy can prime us for the experience.

When we’re deprived of that auditory cue, we can get annoyed. After news reports emerged that Pepsi CEO Indra Nooyi had mentioned her company might consider a quieter version of Doritos for women—an idea PepsiCo later denied they would label in a gender-specific fashion—women Doritos enthusiasts rallied around the Texas state capitol, condemning the perceived gender discrimination. To protest the possible dilution of their favorite snack, they made a spectacle of crunching Doritos as loudly as they could.

See Which Ingredients Cooks From Around the World Love Most

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iStock

Food is incredibly regionally specific, and cuisines have been refined over millennia based on what ingredients have been available and what local cooks have come up with. Even though global trade has made the same spices and other flavor staples available virtually anywhere in the world, Mexican food still tastes radically different from Chinese food, and Italian food from Irish food. We know this intuitively—few of us pick up a bottle of soy sauce thinking we’ll use it in a traditional Italian pasta dish—but it’s still fascinating to see a breakdown of just which ingredients certain cuisines have cornered the market on, as you can in these charts.

Nathan Yau of FlowingData visualized the most-used ingredients in 20 different cuisines, using data on ingredients from Yummly to figure out what distinct flavors and ingredients country-specific cuisines gravitate towards.

Across the world, salt is king. It’s the most-used ingredient in 75 percent of the cuisines Yau looked at, and the only cuisine in which it doesn’t appear in the top five most-used ingredients is Korean food—but, like in other Asian cuisines, Korean recipes use soy sauce more than any other ingredient, and that in itself is very salty.

Because so many cuisines rely heavily on the same ingredients, like soy sauce and salt, Yau also calculated the ingredients most specific to each cuisine: the ones disproportionately used in one country’s traditional cuisine. This is where you start to get a picture of the kind of ingredients we associate heavily with particular regionally specific dishes. Mexican food relies on tortillas; Greek food, feta cheese; Korean, kimchi; Thai, lemongrass; Russian, beets; and Cajun, andouille sausage. Some ingredients may come as a bit of a surprise, though. Southern cooking in the U.S. uses vanilla extract more than other cuisines do, and the French love shallots. Cajun cooks are big fans of celery ribs, and somehow, though numerous cuisines use onions heavily, Brazilian cooks use them slightly more than anyone else.

The data relies on Yummly recipes, so the results are limited to what the recipe recommendation site has available. It's possible that home cooks working in each cuisine do something slightly different that might move the data in another direction. But, since Yummly currently has more than 2 million recipes available, it seems like a relatively large snapshot of cooking options.

Explore the interactive graphic and learn more at FlowingData.

15 Behind-the-Scenes Secrets of The Great British Baking Show

Netflix
Netflix

by Sarah Dobbs

If you’re an American fan of The Great British Bake Off you probably know it better as The Great British Baking Show (though its most devoted fans simply call it GBBO, which saves a lot of time). While its ninth season just kicked off on England’s Channel 4, American audiences are only now just getting caught up on season eight via Netflix. And with new hosts Noel Fielding and Sandi Toksvig taking over for Mel Giedroyc and Sue Perkins, plus Prue Leith taking over for Mary Berry as host, the latest incarnation of the show looks a lot different.

A bona fide global sensation, the baking competition has the power to cause otherwise rational human beings to immediately run to their nearest supermarket in search of obscure ingredients like psyllium or Amarula cream liqueur. It’s a charming, retro, warming hug of a TV show. But how much do you know about what goes on behind the scenes? Without destroying any of your illusions, here are some secrets about how the producers whip up one of the world's most beloved cooking shows.

1. THE REASON WHY IT HAS TWO DIFFERENT NAMES IS SIMPLE.

A scene from The Great British Bake Off
Netflix

If you’ve ever wondered why the series is called The Great British Bake Off in England and The Great British Baking Show in America, the answer is simple: Pillsbury. The Pillsbury Bake Off, which kicked off in 1949, is probably America’s most famous baking contest. And the company didn’t want there to be any confusion among viewers, hence The Great British Baking Show.

2. THE OVENS ALL HAVE TO BE TESTED EVERY DAY.

It’s difficult enough to make a cake that Paul Hollywood won’t declare either under- or over-baked without having to worry about whether your oven is working properly. So for every day of filming, every oven has to be tested. And because this is a baking show, they’re tested with cakes. Yes, every day every oven has a Victoria sponge cake cooked in it, to make sure everything’s working exactly as it should be.

3. EVERY TIME SOMEONE OPENS AN OVEN DOOR, THERE'S A CAMERA WATCHING THEM.

To make sure they catch all the drama, GBBO producers insist that every time a bake is put into or taken out of an oven, the moment must be caught on camera. So whenever a baker wants to put their goodies into an oven, or check if they’re ready to come out, they need to grab someone to make sure the moment gets captured on film. (Which must be a hassle for the first couple of weeks, when there are more than 10 bakers all trying their best to produce a perfect bake at once.)

4. THE CONTESTANTS HAVE TO WEAR THE SAME CLOTHES ALL WEEKEND.

It’s a minor thing, but have you ever noticed that the bakers wear the same clothes for an entire episode, even though it’s shot over two days? For continuity purposes, the contestants are asked to wear the same outfits for the entire weekend. If you’re the kind of baker who ends up with flour all over your shirt whenever you bake up a loaf of bread, the second day of filming could be a bit of a nightmare.

"Luckily they change the aprons so we don't look like a Jackson Pollock painting by the end of it," 2013 champion Frances Quinn told Cosmopolitan. "I think layers [is the answer], but even then you still have to wear what you had on, on top. Difficult."

5. THE CONTESTANTS DON’T HAVE A LOT OF DOWNTIME.

Having any time to spare is not something that season seven contestant Jane Beedle remembers happening regularly for the contestants. "Maybe once or twice, and when they did we would just sit and have a cup of tea and chat with the people around us,” she told the Mirror. "They don't like it if you have nothing to do, so they try and make the challenges as difficult as possible to keep you busy."

6. THE TEMPERATURE IN THE TENT CAN MAKE OR BREAK A BAKE.

Sue Perkins, Mary Berry, Paul Hollywood, and Frances Quinn in 'The Great British Bake Off'
BBC

Forget setting the oven to the correct temperature—the temperature inside the tent is just as important to a bake. "It's completely alien to your own kitchen at home,” Quinn told Cosmopolitan. “The temperature fluctuates—you'd be making a meringue and it would start raining, or we'd try and make pastry and it would be 27 degrees outside. The technical challenges and lack of time and lack of fridge and work space are the enemy on that show."

7. THE ILLUSTRATIONS ARE CREATED BY TOM HOVEY, AFTER THE EPISODE HAS FILMED.

You know those fun illustrations of the confections that pop up when each baker explains what they’re going to make that day? Those are all drawn by illustrator Tom Hovey. He was working as a video editor on the first season of GBBO when the producers realized they needed an extra visual element—so he offered his illustration skills. And while we see the illustrations on screen before the bakers attempt to make them a reality, Hovey told the BBC he draws them “a pack of photos of the finished bakes from the set after each episode has been filmed … I sketch out all the bakes quickly in pencil to get the details, form and shape I am after. I then work these up by hand drawing them all in ink, then they’re scanned and colored digitally, and then I add the titles and ingredient arrows. It's a fairly well streamlined process now.”

Even if a bake goes horribly wrong, Hovey said his “illustrations are a representation of what the bakers hope to create. Even if the bakers don't produce what they’ve intended to I have a degree of artistic license to make them look good.”

8. THE CONTESTANTS DON’T INTERACT WITH THE JUDGES VERY MUCH.

“They very much tried to keep it unbiased,” Quinn said about how the bakers don’t spend much time interacting with the judges. “We saw a lot more of Mel and Sue. Mary and Paul would purely come in to do what we called the royal tour—where they'd come in and find out what you were making, and then they'd come back in for judging. You're not in the same hotel having sleepovers! You form more of a relationship after the show when you see them at things like BBC Good Food or whatever—but they need to keep their distance [on the show]. They're there as judges."

9. MAKING SURE THAT THE TECHNICAL CHALLENGE IS ACTUALLY POSSIBLE IS ONE PERSON'S JOB.

Sandi Toksvig in 'The Great British Bake Off'
Netflix

Another vital behind-the-scenes role is that of the food researcher. It’s down to them to make sure that the elaborate concoction the judges have decided the bakers have to whip up is actually possible, given the ingredients, instructions, and time the bakers will be allowed.

The tent presents its own challenges, too, because it could be hot or cold, depending on the weather, and it tends to have quite a wobbly floor, which can make delicate decorating work trickier than it might otherwise seem. “The tent is just mocked up, so the floor is really bumpy and bouncy because you’d got so many camera guys running around,” Quinn told the Irish Examiner.

10. THE SHOW GOT INTO SOME TROUBLE FOR ITS PARTNERSHIP WITH SMEG.

Part of GBBO’s homey charm has to do with the setup of the tent where the bakers do their cooking, and few appliances spell “retro” as well as a colorful Smeg refrigerator. A viewer fed up with what they described as “blatant product promotion” wrote to the Radio Times to complain, and an investigation was launched into the series’ agreement with Smeg. As BBC guidelines state that a series may "not accept free or reduced cost products" in return for "on-air or online credits, links or off-air marketing,” the broadcaster ended up having to write the company a check for all the times their product got some screen time.

11. THERE ARE NEVER ANY LEFTOVERS.

The judges only take a mouthful of every bake, which seems to leave an awful lot of leftover pastries, cakes, and ridiculously complicated bread sculptures. But don’t worry—none of it goes to waste. “The crew eats all the leftovers," Beedle told The Mirror. "We get some brought to us in the green room so we can taste each other's bakes, but it's only slithers."

12. HUNDREDS OF SEASON FIVE VIEWERS WROTE IN TO COMPLAIN ABOUT “SABOTAGE.”

Midway through season five, contestant Iain Watters had a bit of an issue with his Baked Alaska. Realizing that his ice cream had not yet set, he threw the entire dish into the trash rather than serve the judges a subpar dessert and was sent home as a result. Footage from the episode made is seem as if fellow contestant Diana Beard had removed his ice cream from the freezer. Beard left the show at just about the same time due to health issues, but some viewers (811, to be exact) smelled sabotage—and wrote in to the show’s producers to complain. Media watchdog group Ofcom looked into the matter, but said that they had assessed viewers’ complaints and “they do not raise issues warranting further investigation under Ofcom’s rules.”

Paul Hollywood took to Twitter to clear up what became known as “bingate,” tweeting: “Ice cream being left out of fridge last night for 40 seconds did not destroy Iain’s chances in the bake off, what did was his decision BIN.”

13. MARY BERRY WATCHED BREAKING BAD BACKSTAGE.

Although it looks pretty nonstop on screen, there’s quite a bit of downtime during the show’s filming days. Especially for the show’s judges and hosts. Former judge Mary Berry had one unique way of passing the time: binge-watching Breaking Bad. “It’s shocking,” Berry told The Telegraph. “Then you get into it and you think: ‘Have I seen episode four or five?’ You get hooked. It’s better than motor racing, which [my husband] Paul watches—though I’d prefer Downton Abbey.” She’d apparently rope former hosts Mel and Sue into watching it with her on occasion. What better way to relax during a long day of baking than by watching Walter White, umm, baking?

14. THE APPLICATION FORM IS NO JOKE.

Fancy your chances in the Bake Off tent? If you’ve been inspired by the show and reckon you could nab a couple of Star Baker titles, brace yourself: The application form is a whopping eight pages long, and it’s full of probing questions. As well as giving details of your hobbies, lifestyle, and level of experience with various types of baked goods, it also asks applicants to describe their baking style, and answer a couple of existential-sounding questions.

"It's a long application form. I think it's designed to put some people off, essentially," fourth season contestant Beca Lyne-Pirkis said. "It asks you about everything you have done, good and bad. It's designed to get information about your character, stories, mishaps and successes."

Still fancy applying? Though submissions are not open at the moment, you can keep your eyes open for when the next batch of contestants are being accepted here.

15. THE AUDITION PROCESS IS EVEN MORE GRUELING.

If you happen to make it through the application process, the audition process is even more difficult. “Every person who makes it into the marquee has passed a rigorous series of tests,” GBBO creator and executive producer Anna Beattie told The Telegraph. In addition to the application form, The Telegraph reported that there is “a 45-minute telephone call with a researcher, bringing two bakes to an audition in London, a screen test and an interview with a producer. If they get through that, there is a second audition baking two recipes … in front of the cameras, and an interview with the show psychologist to make sure they can cope with being filmed for up to 16 hours a day.”

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