Medical practitioners and malt whisky

Greetings of the season.

For Christmas this year I thought that I might follow up on two previous posts that have proved to be quite popular on my other blog, which are about the detectable qualities of Scotch whiskies:

• Network analysis of scotch whiskies
• Single-malt scotch whiskies — a network

Medical practitioners have been known to partake of these tipples; and along the way some of them have pondered the question as to whether it it possible for people to reliably distinguish among the various whiskies, in even the most basic way. For example, two medical groups have done some experiments, and published them in the Christmas issue of the British Medical Journal:

• Stephen J Chadwick, Hugh A Dudley (1983) Can malt whisky be discriminated from blended whisky? The proof. A modification of Ronald Fisher's hypothetical tea tasting experiment. British Medical Journal 287:1912-1913.
• EJ Moran Campbell, Diana ME Campbell, Robin S Roberts (1994) Ability to distinguish whisky (uisge beatha) from brandy (cognac). British Medical Journal 309:1686-1688.

For those of you who think you know your whiskies, it turns out to be a lot harder to discriminate them than you think.

Here is the abstract of the first paper:

A modified version of Fisher's tea tasting experiment was performed to test the confident assertions of some members of an academic surgical unit that they could easily distinguish malt from blended whisky. Eight male volunteers from the unit, divided into regular and inexperienced whisky drinkers, were blindfolded and given a glass of each of six whiskies. The whiskies included three malts and three blends, and each subject tasted each whisky six times. They were asked whether the whisky was malt or blended, whether they could identify the distillery, and whether they liked it (ranked on a nine-point scale). Statistical analysis of the data suggested that within the [surgical] unit malt whisky could not be distinguished from blended whisky, and that experience did not alter powers of discrimination. These results suggest that, although "uisgebeatha" has unique properties, the inexpert drinker should choose his whisky to suit his taste and pocket and not his self image.

Here is the abstract of the second paper:

Objective: To assess the ability to distinguish between first rate malt whisky and brandy and between different brands of each. Design: Crossover with two sessions of 12 blindfold tastings of two whiskies and two brandies before and after supper, repeated not more than seven days later. Participants: four volunteers aged 50-68 years, all moderate drinkers of alcohol and members of a wine club. Results: Only one participant produced irrefutable statistical evidence of being able to distinguish between whisky and brandy, correctly identifying 50/51 (98%) samples. The participant who was best able to distinguish between whisky and brandy was also best able to identify correctly the brand of whisky (100%). Conclusion: The results show that some participants could distinguish neither between malt whisky and brandy nor between different brands of whisky and brandy. However, the success of one participant [a Scotsman] shows that "it can be done", and that his whisky specific ability is acquired not innate.

These experiments received comments from some of their medical colleagues, for those of you who might like to read them:

• James Howie (1983) Good motivation but indifferent methods. British Medical Journal 287:1913-1914.
• Douglas G Altman (1983) How blind were the volunteers? British Medical Journal 287:1914-1915.
• Stephen J Chadwick, Hugh A Dudley (1983) In defense of the whisky drinker on the Clapham omnibus. British Medical Journal 287:1915.
• Ken MacRae (1994) A spirited attempt. British Medical Journal 309:1688.

Of these, perhaps the most pertinent one is from both Howie and MacRae, who point out that some of the drinks chosen were rather similar. Obviously, this point alone obviates the need for an experiment at all — if it is known beforehand that whiskies are similar to each other (as shown in the two blog posts linked above), then why do we need an experiment to show it? Except for the fun of doing the tasting, of course!

Finally, Altman notes that "last Christmas I helped to perform a small experiment that demonstrated that white wine and red wine cannot always be distinguished (unpublishable results)." Christmas can have that effect on you.