When guests ordered the "sonic cake pop" at the experimental London restaurant House of Wolf recently, the nugget of chocolate-covered bittersweet toffee came with printed instructions. A small white card showed a phone number that, when called, led diners to the prompt: "dial 1 for sweet, 2 for bitter."
Those who pressed 1 heard a twinkling, high-pitched melody. Pressing 2 brought them a slow, sombre tune composed of low, brassy tones.
The dish is the latest example of a growing movement known as multisensory dining, spearheaded by Oxford University experimental psychology professor Charles Spence, whose résumé includes collaborations with some of the world's best and most cutting-edge chefs, including Ferran Adrià and Heston Blumenthal.
These chefs believe that flavour is made up of not only taste, but all of our senses: what we see, hear, touch and smell. They rely on Spence's research, which shows how every aspect of dining – from the colour and shape of a plate to the music playing in the background – affects our perception of flavour.
Spence said the House of Wolf cake pop, which he created along with artist Caroline Hobkinson, is an example of sensation transference, in which the brain uses cues from one sense – such as the music we hear – to inform another: taste.
He has proved that higher pitches emphasize sweeter flavours and lower tones underline bitterness. This happens for a number of reasons, according to Spence, such as learned experience (such as the ringing bells of an ice cream truck) and biology. The tongue curls upward for sweeter tastes and downward to expel bitter food. (Try making a sound with your tongue curled each way: curling your tongue upward should create a higher-pitched sound.)
"We cannot ever eat or drink without being influenced by the environment," Spence said. "Your brain can't do it. Your brain is always picking up all these other cues and using them to infer what your experience is – how sweet, how tasty, how much do I like it?"
Among his most surprising findings: Popcorn is saltier when eaten out of blue bowls as opposed to red, heavier cutlery generally means better flavour, and desserts taste sweeter on white plates than they do on black ones, which is another example of sensation transference.
Because we're accustomed to seeing desserts served on white plates and savoury dishes such as sushi on black plates, when we see a dessert on a white plate, "our brain is making a calculation," Spence said, and it will expect to pick out sweeter flavours. This was illustrated in an experiment conducted for Adrià at the now-defunct El Bulli's test kitchen in Spain (where chefs experimented with new techniques – Momofuku and Noma also have test kitchens). Diners rated strawberry mousse 10 per cent sweeter and 15 per cent more flavourful when served on white plates. The results have been recreated in a lab using different types of desserts.
Some of Spence's findings are culturally specific. For example, simply adding the scent (not the taste) of vanilla to a dish will make it seem sweeter to most North Americans or Europeans, he said. But in Japan, where vanilla is often used in savoury dishes, adding the scent will cause the dish to taste saltier.
Spence, who leads Oxford's Crossmodal Research Laboratory (it studies how senses work together), has won major international awards for his research, including the prestigious Experimental Psychology Society Prize and an Ig Nobel Prize for his work on how the sound of crunching potato chips affects the snack's flavour. He also serves as a consultant for major food companies such as Starbucks: He helped the company develop a soundtrack to complement its coffee.
Chefs such as Blumenthal, owner of The Fat Duck in Bray, west of London, have used Spence's research to manipulate the senses – often introducing technology in the process. Blumenthal's Sound of the Sea (oysters, razor clams and uni served on a "sand" of tapioca and fried panko, then topped with seafood foam) is served with an iPod tucked into a seashell so that diners can listen to the sound of crashing waves as they eat.
Spence, who helped to concoct the dish, has shown that diners find seafood flavours stronger and saltier when they hear the sound of the ocean, as opposed to, say, the clucking of chickens. In the future, he would like to see even more technology in dining rooms: musical plates and images projected onto tables.
At Paul Pairet's Ultraviolet in Shanghai, the 10-seat dining room is outfitted with 360-degree video-screen walls, speakers and scent diffusers so that courses can be paired with images, sounds and aromas. In Canada, drinks at Toronto's BarChef are served amid a haze of scented smoke or mist, while Marc Lepine of Atelier in Ottawa has handed out red-lensed eyeglasses to alter the colour of meals, and created a Michael Jackson-inspired chocolate truffle topped with pop rocks, which is delivered by a server wearing a single white glove as The Way You Make Me Feel blasts on the restaurant's speakers. But Lepine's experiments are not exactly based on science, he admitted. "We just like to do things that make people feel a little silly and childlike," he said.
It's tricks like these that cause some critics to dismiss multisensory dining as precious and gimmicky, and accuse the movement of being more about a chef's ego than the food itself. In a story in February's Vanity Fair magazine, titled "Tyranny – It's What's for Dinner," writer Corby Kummer described drawn-out, "deliberately disorienting" meals such as the ones at El Bulli as a bid "to shift the balance of power from diner to chef. They demanded unconditional surrender."
But Spence disagrees, arguing that his findings can be used by anyone. "Once you understand that sound affects flavour, you can try pairing different wines with different music," he said. "Or, if I know serving desserts on a white plate enhances the sweetness of a dessert, that's something I want to do today and thereafter."
Though Spence is aware that some see his ideas as radical or far-fetched, he is not overly concerned. "With these test kitchens, it's hard to say whether it's an experimental lab or a restaurant," he said. "The boundaries blur, and that's part of the fun."
Research conducted by experimental psychologist Charles Spence shows that everything about the dining experience – from the colour, texture or shape of your plate, to the sounds you hear while eating – affects flavour. See for yourself. Below are some tests, based on Spence's research, that you can recreate at your next dinner party.
White plate, black plate
Try serving the same dessert to your guests on both black plates and white ones. Spence conducted this test using strawberry mousse at El Bulli's test kitchen in Spain (though the test has been recreated using different types of desserts with similar results). The dessert on the white plate should taste sweeter.
Divide the same yogurt into different bowls of varying weights, then have your guests taste it out of each bowl. Ask them which one has the best flavour. When conducting this experiment, Spence found that respondents overwhelmingly graded the yogurt in the heavier bowl as having the best flavour. This, he said, is because we tend to associate heavier items with higher quality.
Cotton and gravel
Serve your guests a bowl of ice cream or sorbet while asking them to hold something soft, such as cotton, in their other hand. Ask them to describe the texture of the ice cream. Then, have your guests taste the same ice cream while holding something rough to the touch, such as gravel. Ask them again to describe the ice cream's texture. In Spence's tests, respondents typically described the texture of the ice cream as smoother and softer while holding the cotton, and rough or gritty while holding the gravel.