Professor Charles Spence, a professor of experimental psychology at Oxford University, has made a series of remarkable discoveries about how the human senses interact and affect one another. It’s a journey that’s led him to test the limits of gastronomy, through working with such star chefs as Heston Blumenthal, whose world-famous dish ‘Sound of the Sea’, developed out of their collaborative research. The dish arrives with a pair of headphones that pipe in the sound of the sea as the diner eats – because it turns out the sounds enhance the taste. In 2008, Professor Spence won the Ig Nobel Prize for Nutrition for his work on the ‘sonic crisp’ – the discovery that the perception of a chip’s freshness or staleness is affected by changing the sound the crisp makes when it’s bitten. Professor Spence is also a consultant to a number of multinational food and beverage companies.
What are you working on at the moment?
All sorts of stuff. For example, we are doing a lot of research on the plating of food, looking at how the arrangements of plating food affects willingness to pay. Sonic seasoning, which is using music to match and accentuate certain taste flavour, texture in food and drink, is another major focus for our research.
Let’s get straight into the concept of music and wine pairing. How much of the effect comes from an intrinsic quality in the music, and how much from the cultural baggage we bring to it? e.g. is it the music that does the work, or the music’s association with attributes like grandeur, history, etc
Those are two distinct ways to match or pair and they both have their value. There is a large body of research out there talking about sensation transfer. This is the idea that what one feels about one thing influences, how you evaluate something else that is happening at the same time.
In our work, we focus on the kind of correspondences between sensory attributes, between sweetness, bitterness, sourness, salty, umami, particular aromas, and the pitch of sounds, say.
Normally, we bring people into the lab in Oxford or test them online and have them taste or smell – or imagine tasting or smelling– something familiar and we give them a virtual keyboard where they can change the pitch of a sound, and the instrument making it. We ask them to taste or imagine a smell and then play the keyboard until they find the sound that matches. It seems strange to people and they often say, ‘I don’t know what I’m supposed to do’, but we find they are consistent in the matches they make.
Can you give an example?
We find that bitter tasting foods – black coffee, dark beers, dark chocolate – will be matched with a low-pitched sound by the majority of people.
There is emotional component or emotional mediation to some of these matches, meaning that you match flavours and sounds based, in part, on their emotional appeal – liked with liked, disliked sounds with disliked tastes/flavours. But that is certainly not the whole story. For example, we have looked at the matching of low-pitched sounds to dark chocolate. We have taken two different groups of individuals: one group, known as super tasters, are less likely to like dark chocolate because they’re more sensitive to the bitterness, and [one normal group]. We ensure everyone is tasting the same chocolate, but their rating differs. One group likes the dark chocolate more than others – but both match a low pitched sound to the chocolate.
Do you think there might be a biological reason why we associate certain sounds and flavours?
I suspect there are a number of explanations. Many of these surprising connections probably reflect the environment. Our brain picks-up on the regularities of the environment. Most fruits will go from green, sour, and unripe with low nutrient content through to redder, riper, and sweeter with more energy. When your brain learns that red things turn out to be sweeter, you’ve got a connection between red and sweet that’s useful to you. If you look at new-born babies, they will all stick their tongues up and out to ingest or lick a sweet taste. They will stick their tongue out and down to eject what might be poison. Rat, human and chimpanzee babies all do this. The pitch of the gurgle a baby makes is going to be systematically different if the tongue is up or down. This means that there is likely a correlation out there [because the baby’s gurgle will automatically be deeper when their tongue is down, meaning they could come to associate a lower sound with bitterness].
How can this research be applied by a restaurant or wine bar?
There’s a café in Vietnam that only plays sweet music and which has reduced the sugar content in their cakes and pastries and drinks, so whatever you order from the menu, the cream tart or apple sponge, they can give you a slightly less unhealthy product that tastes as good as always.
Restaurants have been getting louder, partly because of the hard surfaces, and when you see the measurements from restaurants around the world, they are coming in at over 100 decibels of noise. It’s not just damaging the hearing of serving stuff but also likely to suppress your ability to taste the food.
Is it better not to have music at all, especially if the music is enhancing one particular attribute (e.g. sweetness) when they might be wanting something bone dry or savoury?
We have been working with hotels and hotel chains to think about the music to play in the restaurant. There is already research out there that if you play French music, people are more likely to order French wine. If you play classical music, people are likely to pay more. There are ways of setting a sound track for a restaurant that are designed to nudge customers towards wines that have a bigger return, regardless of what food they order.
Can you train yourself out of being affected by environmental influences? For example, is it possible for wine judges to learn to taste without being affected by the environment they’re tasting in?
We have been wondering if wine experts would be less influenced by sonic seasoning, say. Can they learn to focus on the flavour experience and ignore everything else? That turns out not to be the case. We tested more than 150 winemakers at the International Cool Climate Wine Conference in Brighton, we found they too were influenced by the music playing in the background. One of my students is the captain of the University of Oxford blind tasting team and at the same time she is doing a PhD on music and wine, so I think you can have an interest in acquiring wine knowledge expert and at the same time acknowledge these other influences.
Assuming the background is constant, as it is in wine competitions, can people taste objectively?
The experts turn out to be not able to do many of the things they claim. We took three or four people who have written books on Champagne, who all claim that the proportion of white to red grapes will change the expression of Champagnes, yet who under blind tasting conditions couldn’t correctly identify the difference at all. And yet my student is going through the wine exams and she spends every day of the week training, so there has to be something there.
We can identify the foods that we eat, so doesn’t it make sense we can identify wine as well?
We do have the physiological capacity to detect sweet, sour and umami and discriminate between a billion different odours, so we are better than most machines could ever hope to achieve. As soon as you start putting things together, you have multiple tastes and aromas, and that’s where things start to break down. The taste buds don’t operate independently. If you had salt to your tonic water it becomes sweeter. A fruity aroma may add perceived sweetness to a drink.
One of the disconnects I see is in writing about wine. You sometimes get a wine expert giving a 1,000 word description of a wine, whereas when you give people odour mixtures in a laboratory – with no more than six different aromas, each one of which the experts can identify in isolation – as soon as they’re mixed together, the expert can pick out no more than two or three. Perhaps the odour mixtures that the scientists test with are somehow importantly different from what assaults the senses on tasting a well-structured wine. It’s a case of more research needed.
What has been the taste discovery that has surprised you the most?
It was when we played the sounds of the sea and made seafood taste better. This was in 2006 at a conference in Oxford with Heston Blumenthal. We never thought it would work, but it was the first time that showed that ambient sounds can change what you taste. Now, ten years later, people say of course, it’s obvious. The thing that was also surprising at the time is sonic seasoning where music can change the taste.
You’re appearing at the MUST conference in June. Will you take the occasion to test some theories on the audience?
I hope so. I tend to be a bit last minute in the planning, but given the chance, I always will when I can.
Professor Charles Spence is a keynote speaker at the MUST – Fermenting Ideas summit, which takes place from 20 to 22 June 2018 in Portugal.
