Is Féidir Linn: Obama was right

Image: WhiteHouse

Barack Obama visited Ireland this week and while visiting his ancestral home in Moneygall, he announced that the Guinness really does taste better in Ireland than anywhere else in the world.

"The first time I had Guinness," Obama said, "is when I came to the Shannon airport. We were flying into Afghanistan and so stopped in Shannon. It was the middle of the night. And I tried one of these and I realized it tastes so much better here than it does in the States."

"What I realized was, is that you guys are -- You’re keeping all the best stuff here!”

And maybe he's right.

According to a recent piece of research published in the Journal of Food Science, Guinness does not travel well. 

Like all great funny stories to come out of a pub, it started with an Irishman, Englishman, Dutchman and German walking into a bar. The four spent a year of their spare time (probably quite happily) testing the stout across 14 different countries.

During what the authors light-heartedly describe as "extensive pretesting", a number of factors were considered as to what makes the perfect pint. Ultimately this included such measurements as the height of the head on the pint, temperature and flavour.

Additionally, in order to capture the entire experience, such factors as pub temperature, bartenders sex and nationality, level of experience and technique were also considered. It was certainly a thorough approach. 

Even the presence of females in the drinking company was considered.  The authors found that the presence of women did not “inflict any unplanned blinding of the testers, who were all dedicated to the measurements”.

For the statistically minded amongst us (come on, admit it), the research paper also involved one of the most appropriate uses of a statistical test I've seen.

From the factors considered, the authors were able to score each pint using a specially designed Guinness Overall Enjoyment Score (GOES) which, of course, needed to be compared from country to country.

To do this, the authors used what is known as Student's t-test: a relatively simple way of establishing whether there are significant differences between two groups of data, in this case, between pints in Ireland and pints consumed outside Ireland.

Student: Willaim Sealy Gossett

This is particularly apt, given that the t-test was developed at the Guinness brewery in Dublin by one William Sealy Gossett. In 1908, Gossett developed the test to monitor and improve the average annual yield of barley. Due to the competitive advantage the test could provide, Guinness were reluctant to let Gossett publish the work under his own name so he used the pseudonym Student.

The results of this t-test are clear. Pints consumed in Ireland had a mean GOES score of 74, compared to a score of 57 in pubs outside Ireland. While Ireland may not necessarily keep the best stuff to themselves, the science is clear, it tastes better over here.

[Is Féidir Linn: (Irish) Yes we can!]

An edited version of this article appears on the Guardian's Notes and Theories Blog. You can read it here. 

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