The Multisensory Psychology of Wine Tasting

On Monday I spent the afternoon drinking wine, all in the name of science: I took part in the world’s largest multisensory experiment in the psychology of wine tasting.

The premise behind the research is simple: How do environmental factors like colour and sound affect your sense of taste? The answer’s a little more complex. Charles Spence, an experimental psychologist at Oxford University, has explored the multisensory experience of food and drink in a range of experiments that have seen participants sip whisky under different coloured lights, drink wine to Tchaikovsky and Mozart, and munch on cinder toffee to different soundtracks.

In his latest public experiment, around 3,000 people descended on London’s South Bank during the Streets of Spain festival to visit Spence’s “colour lab,” sponsored by winemaker Campo Viejo. Before going through the colour lab myself, I sat down with Spence—over a glass of wine, naturally—to find out more about the study.

He explained that participants held the same glass throughout the experiment, so they knew they were always drinking the same wine, but were asked to rate it under white, green, and red light, sometimes combined with one of two specially composed snippets of music. It’s basically a formal way of studying why that amazing rosé you happily slurped on a Spanish beach doesn’t taste as good when you bring it home. “Everyone has had that experience but there’s very little science around that phenomenon, and that’s what we've been looking at for the last two or three years,” said Spence.

His team will analyse all the data collected over the four-day experiment to see how closely they correspond to previous lab-based trials, and whether they glean any new information from the larger pool of subjects, such as gender differences. He said some people gave the wine the same rating in each condition and some made unexpected judgments—“but the majority are in line with our expectations, showing about a 10 to 20 percent change in their ratings of the wine in the glass.”

When I entered the colour lab with a small group, we were first all given a tasting strip, which looked like a tiny piece of paper and was laced with a chemical known as PTC (phenylthiocarbamide). We were told that some people wouldn’t be able to taste the chemical at all, but others would get a horribly bitter taste. If you taste it, you’re a genetic supertaster, which basically means you have more taste buds. The point was to see if supertasters were affected any differently by the multisensory experience, and you could tell from everyone’s focused expressions as they put the strip on their tongue that they were just dying to have those bragging rights.

I tasted nothing but paper at first but then got a shock of something like nail polish remover, and admittedly felt pretty smug at my apparent tasting proficiency. We were then given a black opaque glass of Rioja (Reserva 2008, if that means anything; I’m no wine buff) and sent into an empty white room with a scorecard and a glass of water for palate cleansing.

We all stood facing the white walls and took a sip, which we had to rate in terms of how fruity and intense it was, and how much we enjoyed it. The lights changed to green (generally considered sour) for one minute, then to red (sweet) accompanied by “sweet” music characterised by higher pitched tones, and finally to green accompanied by “sour” music.

Spence has done plenty of research to show that red makes things taste sweeter and green makes them more sour, but I asked him why that was the case. He said that in this experiment it was likely some kind of “non-verbal priming effect.” In the same way that if you’re told a wine tastes of cherry or chocolate or whatever you’re more likely to think you taste those ingredients, if you’re shown red you’re more likely to associate it with sweetness. “Most people, when they think of sweet, they think of red as the first colour to come to mind,” said Spence. This perhaps goes back to the colours of nature: when fruits are green, they’re unripe and sour, and when they’re red, they’re ripe and juicy. “Either we’ve learnt that or it’s innate—who knows which?” said Spence.

As for the music, Spence had two hypotheses. He suggested that babies’ facial expressions could give us a hint. “We’re all born sticking our tongue out and up to sweetness, to goodness, to calories, to growth, to mother’s milk; we all stick our tongue out and down to bitterness,” he said. When you have your tongue up you make higher pitched sounds, and when it’s down they’re lower—like “eurgh.”

Linguistic associations may also hold a clue, and Spence pointed out that scents and tastes are often described in terms of music. “So if someone’s describing a perfume or a wine, they might say it has high notes. Citrus, straw, lychee—those are all high notes; the tobacco, tar, dark chocolate are all low notes,” he said. We don’t know why that is, but Spence is working on it.

The music in this experiment was specially composed by some of Spence's colleagues in Germany. They started by getting composers to choose a note and instrument to match sweet, sour, bitter, and salty tastes in the lab, then played them to other people to see if they could decode the flavour behind the sound. Spence said they correctly identified sweet and bitter about 90 percent of the time, and sour about 70 percent. “We’re still struggling to get a good sound that has a salty taste,” he added.

When I tasted the wine in the different conditions, I definitely noticed some differences, though I did struggle a bit to rate the tastes on the various linear scales. Maybe it was my lack of wine drinking sophistication, or maybe it was just all too much for my super-tastebuds, but I found myself overall a bit confused. I felt like the music had a stronger effect on me than the colours, and I rated the red one with music the highest, but struggled to compare the others. I asked Spence beforehand if it was a problem that I’d spoken to him in advance and knew what I should be tasting. He admitted there were practical restraints to doing such a large experiment but pointed out that, in reality, wine critics and judges are often primed in advance as to what they should taste—notes of cherry, undertones of tobacco, and so on—so it was still worth investigating.

The aggregated results over the weekend will inform Spence and his team’s ongoing research, the applications of which are plentiful. He’s already worked with places such as Heston Blumenthal’s Michelin-starred restaurant the Fat Duck and cocktail makers at Colebrooke Row, to apply his multisensory findings to the real-life dining and drinking experience. He envisages it trickling down to consumer products in the near future, such as lighting and music suggestions on packaging, or sensory apps.

He's also turning his attention to the idea of space food, with an eye on the in-air meals on Virgin Galactic’s commercial space flights. As he said, “If you’re going to pay however many thousands of pounds to go up in space you probably want a pretty damn amazing meal.”