Wellll...."Tastes" may be the wrong word to use here. Let me explain a bit.

Fans of Guinness, of which I am one, are an odd lot, almost to the point of obnoxiousness. Those who've had a pint of it in Ireland even more-so. These folks will claim, with little thought to the accuracy of the statement, that a pint of Guinness in Ireland tastes different from the pints had here in the States(and presumably other places other than Ireland).

"Sure, this is tasty", one might say at a bar will slowly working on a pint. "But you never have had a true Guinness until you've had one in Ireland."

As I've noted before, these people should be mocked. A round trip ticket to Dublin will cost me roughly $900. I like beer, but I have yet to come across one worth nearly a grand.

But, is there something to their claim? Does Guinness in Ireland taste different from one served in the States?

The answer is possibly yes, but it may have to do more with mouth-feel than with actual flavor. Guinness, for those of you who are not fans, do not only have Carbon Dioxide added to the taps. Guinness promotes using a gas mixture containing both Carbon Dioxide and Nitrogen, a process called nitrogenization. This is used as a gas to the taps with a mixture of nitrogen and carbon dioxide. The ratio may vary from beer to beer, bar to bar, or even from country to country. We here in the States typically run a mixture of Guinness around 70% nitrogen to 30% CO2. In Ireland, that ratio goes up to 80/20.

So, that difference in taste? It may be nothing more than a change in how the texture of the beer is perceived on the palate.