Beyond the tongue

Making sense of taste


Pinning flavour down is like trying to grab a fish underwater. Just when you think you have it, your prey wriggles free. Imagine you’re having a drink with your mates. At first you think your beer tastes a certain way, then someone mentions something and it alters your perception entirely. The beer hasn’t changed but it doesn’t taste the same. Familiar?

Perhaps you’ve noticed it at home, too. You sip your beer and taste what it has to offer. Then you pick up the can and read the tasting notes on the back. With your next mouthful a flavour that wasn’t there before swims to the surface and you ask yourself, is it there for real or are you imagining things?

Here’s the thing: the mechanism for figuring out what a beer (or anything else) tastes of goes far beyond sticking it in your mouth. Psychologists are beginning to understand the role played by all sorts of seemingly unrelated factors. The colour of the packaging, the shape of the glass, the sounds in the room around you, all of these things impact our experience of food and drink. It turns out taste is super weird.

Messy science

Professor Charles Spence is the mac daddy of flavour weirdness. He runs the Crossmodal Research Laboratory at Oxford University’s experimental psychology department. “I’ve always been interested in the senses, and in applying sensory science to the real world, but it took me quite a long time to get into flavour,” he says. “It’s actually the perfect place to be, given that [eating and drinking] is one of the most multi-sensory things that we do, and it’s something that everyone’s got an interest in at some level.”

He is talking to me from a mountaintop in the Colombian cloud forest, where he is on sabbatical with his Colombian wife. They have a small farm there, and he is doing lots of writing. He warns me that our Zoom call may be cut short at any moment. “If it rains or is windy here in mountains, then electricity and internet sometimes disappear.” I mention that it all sounds a bit Indiana Jones to which he replies it’s even more than I think. “Last month we discovered an Indian sacrifice rock in our garden!”

Spence first became interested in the links between taste and other senses when, as an undergraduate, he read about experiments run by Danish psychologist Kristian Holt-Hansen in the 1960s and 70s. I can see why. Even for the time this was some trippy shit.

In one, Holt-Hansen had people taste Carlsberg beers and twiddle oscillators until the tone they produced ‘matched’ the flavour of the beer.

“With higher alcohol people chose a higher-pitched sound,” Spence says. Oddly enough, people’s choices did seem to converge around a certain point, which Holt-Hansen called the ‘pitch of harmony’.

Freaky resonance

But it gets weirder. Next Holt-Hansen played this ‘pitch of harmony’ back to people while they were drinking beer. “They had all sorts of weird experiences,” says Spence. You can still hear the excitement in his voice as he recalls reading it for the first time. People said they felt like they were floating on air, or that it made their hands tremble so much they were afraid of dropping their glass. “People said ‘my head was spinning and exploding’, or ‘my arm was levitating’. It makes you think you just can’t believe what people say. Were they on drugs or something? This can’t be real research!”

Despite the suspect results, the experiments suggested Holt-Hansen was onto something, and that the area was suitable for further study. “Half a century later there is a whole science emerging around this,” says Spence.

For instance, we now know that loud music in bars makes us drink faster, and drink more. What isn’t clear is why this happens. It might simply be that the loud music hampers conversation, so there’s not much left to do but drink. Or there could be something deeper at work. It could be that the noise itself alters the way we experience our drinks. For instance we know it becomes harder to discriminate the alcohol content of our drinks as background noise increases. And psychologists reckon noise may even change the way we experience the flavour of our drinks.

Sniffin’ sticks

In 2011 researchers found that background noise affected people’s ability to tell one aroma from another. They asked people to pick the odd one out from a trio of “sniffin’ sticks” — think smelly felt-tip pens — while listening to various kinds of background noise through headphones. Their results showed the sound of someone talking interfered most with people’s ability to differentiate between smells. General background hubbub made the task a little harder, but not as much.

In another study, from 2014, researchers asked people to rate how much they liked six different food-related odours while listening to either music or white noise. People found the smells significantly less pleasant when they were listening to white noise compared to when they were listening to music.

We still don’t know for sure what causes these effects. Early results from studies using brain scans suggest that noise loud enough to capture our attention may interfere with the brain’s ability to process smells. Another possible explanation is sensation transference. This is the theory that our feelings about a particular background noise may carry over to influence our perception or enjoyment of food and drink. So if we drink beer while listening to music we like, we’re more likely to enjoy the beer, and vice versa. There have been several studies which proved this transference effect in other areas, so it is reasonable to suggest it might also be true with food and drink.

If we drink beer while listening to music we like, we’re more likely to enjoy the beer, and vice versa

One of the most famous applications of all this was the Sound of the Sea dish that Spence created with chef Heston Blumenthal at his restaurant The Fat Duck. Waiters delivered this seafood dish to the table along with an iPod hidden inside a conch shell. Diners listened to seaside sounds on the headphones as they ate. The idea was that the sounds would evoke ‘sensorial memories of the seaside, which cross the threshold of consciousness and combine to strengthen the experience and heighten perception.’ Or, in simpler terms, it would make the fish taste fishier.

“The surprising thing about the Sound of the Sea was that it worked,” says Spence. “Playing seaside sounds made the seafood taste better. Everyone else afterwards said: ‘Well it’s obvious, you’re matching the congruency of the environment to the food. What else was going to happen?’ But when you tell them about music changing tastes, that’s much harder to make sense of. Why would that be true? These things are not related.”

Beer in a chipped teacup?

It’s not just sound that can change how we taste things. Vision plays a big role too. The beer trade has long known that if you match a beer to its branded glassware it can increase sales by as much as one-third. But why?

Spence says we associate particular drinking vessels with particular drinks. In other words, when the glass and its contents match, according to our past experience, we judge that pairing as being congruent. If they don’t match, it’s incongruent. “Serving coffee in a tea cup is a bit incongruent, but not as much as serving it in a beer glass, and so on.” Research shows that we think drinks taste better when they are served in a congruent glass, and vice versa.

The basis for why we think some pairings of drink and vessel work together may run deeper than we realise. “Who knows how these different glasses came to be the ones that we associate with different drinks,” says Spence. “I suspect there is something… a kind of rightness… There’s more than just your prior experience that makes something congruent.”

For example the shape of the glass may play a role. “There’s some sort of fundamental link [whereby] we associate round things with sweet tastes and angular shapes with bitter,” Spence explains. This may be why we associate Coca Cola, for example, with the classic curvy Coke glass.

An Australian study from 2017 found that people thought a craft beer tasted fruitier when it was served from a beer glass with rounded sides compared to the same beer served in a glass with straight sides. They also found the beer more ‘intense’ from the round-sided glass. (Research on wine drinkers from 2003 reached much the same conclusions but relating specifically to aroma rather than taste.)

Bottle vs can

These effects can even extend to a drink’s packaging: “We’ve done a few studies with Andrew Barnett of Barney’s beer,” Spence tells me. “We did one showing British consumers rate beer as tasting better from a glass bottle than the same brew packaged in a can. And that worked even when you only held the bottle or can and then poured it into a glass. You were rating the taste of the drink from the glass, and the glass was the same for everybody, but your knowledge that it had been in a heavy bottle made it taste better.”

This could be, in part, be down to the difference in weight. Humans are suckers for heavy stuff, we think it seems more ‘premium’. “When you hold something heavier — if we add a little weight to a bottom of a can of Coke or a box of chocolates or anything else — it makes things taste better,” says Spence.

Humans are suckers for heavy stuff, we think it seems more ‘premium’

A beer’s colour can also influence how we taste it. Spence has run studies where volunteers were served two beers, one pale and one dark. These were actually the same beer with one half of the brew taken out and coloured using a flavourless dye. The look of the beers had a significant effect on people’s expectations. People thought the dark beer would be more bitter, fuller bodied, higher in alcohol, and more expensive than the pale one.

A similar study a couple of years later moved on from expectations to taste. This time volunteers who usually preferred pale beers judged the dark beer as tasting sweeter. The study also found that people tasting a beer under blind conditions thought it had more body compared to tasting the same beer under sighted conditions. (This was the same for pale and dark beers.)

Primed for flavour

Spence says that priming — i.e. setting expectations based on subtle environmental cues — can “probably get you most of the way” to explaining why these effects manifest themselves.

If you were holding a tasting, for example, and wanted to draw people’s attention to the beer’s bitterness, you could have them feel rough textures before and during tasting, as opposed to smooth ones. And if you wanted to bring the fruit character forward in their minds you could serve it to them in a rounded glass. It would even be enough to have them look at rounded shapes shortly before tasting.

“You can’t use this to turn water into fruity beer,” Spence warns me. “It has to have those properties to begin with. But you can accentuate the properties it has. That’s maybe easier when people are tasting something they’re a bit less familiar with, and maybe easier when they’ve got a complex tasting experience such that they can’t really take it all in at once, but in those situations you can ramp up a property of the beer by 10 percent to 15 percent by priming and drawing their attention to it.”

If you want to try this for yourself there are ‘sonic seasoning’ playlists online that you can listen to while drinking a beer. Personally I might be more inclined to focus on the glassware part of all this. It might just be the justification I need for adding a few more beer glasses to my already large collection.

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