Comment · Tue, March 12, 2013
St. Patrick's Day delivery to a single Irish bar in Minneapolis
What they were answering
TheMacMan · 3 points
The packaged product is but I don't know about the kegs which are always kept cold even during shipping.
u/MisterYouAreSoDumb
http://beeradvocate.com/articles/662
According to Fergal Murray, one of their brewmasters, all their batches are pasteurized.
Even more interesting:
Every keg of Guinness Draught imported to the US comes from St. Jamess Gate in Dublin (though Guinness Extra Stout is made in Canada).
And then for Guinness brewed for other markets:
And then theres Guinness Essence, a key ingredient in the beer brewed outside of Jamess Gate. Basically Guinness without the alcohol, Guinness Essence is shipped from Dublin to Guinness breweries and contractors around the world, where its added to a base beer brewed locally. The entire process is conducted according to strict guidelines; according to Murray, it lends a touch of Dublin to every batch, regardless of place of origin.
So it seems that US kegs of Guinness are actually brewed in St. James Gate, and are pasteurized. The bottles and cans I assume are from other breweries, which add this special "essence" in at time of brewing.
EDIT: After some more reading, the kegs in Ireland started pasteurizing as well over 10 years ago. So there is absolutely no difference in US kegs and Ireland kegs. Just time to ship and the cleanliness of the bar you drink at.