'Shaken, Not Stirred'

James Bond preferred his vodka martinis "shaken, not stirred", but is there any difference? Yes - according to a psychologist and chemist who like their science with a twist.

'Shaken, not stirred' - apparently there is a difference.
To celebrate the centenary of the birth of Ian Fleming, creator of the world's most famous secret agent, Professor Charles Spence and Dr Andrea Sella will be unveiling the secrets of 007's favourite drink and a range of other cocktails, at a lecture at the Cheltenham Science Festival next month.

Prof Spence is a psychologist who has worked with molecular gastronomist Heston Blumenthal to unravel the secrets of how we interpret taste, while his fellow Bond addict is a chemist at University College London.

To these aficionados, the creation and presentation of a cocktail is a true science: "molecular mixologists" can create alcoholic alchemy, from Bond's dry martini to daiquiris and beyond.

Take the all-important issue of shaking rather than stirring the martini. In 1999, a group of students at the University of Western Ontario in Canada led by Colleen Trevithick (and overseen by her father John, a professor of biochemistry) decided to test Bond's preference in a series of experiments on gin and vodka martinis.

They studied the martinis' ability to deactivate hydrogen peroxide - a substance used to bleach hair or disinfect scrapes, and a potent source of the free radicals linked to ageing and disease.

While the detailed chemistry is not fully understood, martinis were much more effective than their basic ingredients - such as gin or vermouth - at deactivating hydrogen peroxide, and about twice as effective when shaken.

The martini must contain an antioxidant that deals with the peroxide, and which works better after shaking. (The olives that are normally added might also have an effect, but were left out as being "too difficult to model".)

In their analysis of the results in the British Medical Journal, the team concluded, reasonably enough, that Bond's excellent state of health "may be due, at least in part, to compliant bartenders".

And Dr Sella believes that shaken martinis are not only healthier, but also taste better. This is due to what experts call "mouthfeel" - the shaken martini has more microscopic shards of ice, making its texture more pleasing.

He plans to test this hypothesis at the Cheltenham Festival, where he is not expecting a shortage of volunteers.

So Fleming's creation obviously has impeccable judgment - but some of the scientific subtleties of cocktails did escape him. When Bond creates a martini called "The Vesper", named for his lover, Vesper Lynd, he orders: "Shake it very well until it's ice cold."

In fact, says Dr Sella, cocktails are actually colder than ice, thanks to the same phenomenon that occurs when salt is used to keep ice off roads. Salt does not actually "melt" the ice, but creates a solution with a lower freezing point.

The same effect occurs with sugar, of which there is plenty in cocktails - in the case of "The Vesper", it comes chiefly from the addition of a French apéritif, Lillet.

Dr Sella will demonstrate the colder-than-ice effect at the festival, but molecular gastronomists are already exploiting it as they experiment with taste and temperature. At elBulli in Spain, the legendary chef Ferrán Adrià has come up with the Hot and Cold Gin Fizz - a chilled gin-and-lime liquid topped with a hot foam of the same.

Martinis pack quite an alcoholic punch - but how quickly would they have an effect on 007? Alcohol is alcohol, but it is taken up at different rates, depending on many factors.

Drinks that are creamy or sugary will creep up on you more slowly, hence the idea that a glass of milk will line your stomach. But the absence of bubbles in a martini would slow the uptake of alcohol: the fizz of champagne speeds up the absorption of ethanol into the bloodstream.

Bubbles have other interesting properties: drinks such as Coke and champagne contain a great deal of carbon dioxide, but fizz slowly, and always from the same place on the glass, where the bubbles form around imperfections on the surface.

The best example of this "nucleation" effect, says Dr Sella, is the eruption that occurs when mints called Mentos are popped into Diet Coke.

Each sweet has thousands of tiny pores all over its surface, which function as nucleation sites for bubbles.

Dr Sella plans to see if a sparkling cocktail such as Kir Royal fizzes more than a drink such as Pimms that has other objects added to it, such as pieces of fruit and ice. He will measure the carbon dioxide released by putting a balloon over the container.

The effect of cocktails is not just chemical, but also psychological. Prof Spence explains that our perception of cocktails is affected by the shape of the glass - people do not enjoy drinks as much if they are served in a container they feel is inappropriate.

Also, to maximise the strength of your martini, make sure it's poured into a flat glass. "Researchers have shown that people drink up to 88 per cent more when consuming drinks in short, wide glasses than in tall, narrow glasses that hold the same volume," he says.

"Surprisingly, even experienced bartenders fall prey to this vertical-horizontal illusion. One study showed that veteran bartenders pour 26 per cent more alcohol into tumblers than highball glasses when measuring out a shot of spirits."

The appearance of a drink can also affect how happy we are with it: our brains make a pleasant association between the colours of ripening fruit and increased sugar content.

"Such colours, particularly bright reds, are especially powerful visual cues," says Prof Spence. "When incorporated into a drink, they can dramatically change the perceived flavour, as well as increasing the perceived sweetness by as much as 12 per cent."

French researchers tested this by using an odourless dye to colour white wine red. The wine tasters who tried the result used typical red wine descriptors, suggesting that its colour played a significant role in how they thought of it. "In cocktails, I'll look at how the very same colour can lead different people to think of, and therefore taste, very different flavours," says Prof Spence.

He also points out that studies suggest that music can affect how quickly we get through drinks: upbeat muzak in the background leads to more cocktails being downed.

Even the link with Bond will affect the way we perceive a martini. Punters are likely to pay more for a cocktail if it has a more elaborate name or - in this case - reputation.

Studies at Oxford University suggest that words can influence the perception of smells: as you might expect, a brie?like smell is more popular when labelled "cheese" rather than "body odour".
And there are differences in the extent to which people use their senses to rate drinks. About a quarter of the population are "supertasters" - those born sensitive to bitter flavours who ignore visual tricks such as dyeing white wine red.

Despite his excellent taste in shaking rather than stirring his martini, Bond is probably not among their number: they would be likely to taste the vermouth and olives as bitter and unpleasant.

Instead, like most of the population, his perception would more likely be dominated by his eyes. This neatly ties into other aspects of the Bond legend, points out Prof Spence - in particular his liking for the best-looking women.

[Via Telegraph]