Irish people swear Guinness tastes better in Ireland. So four scientists spent a year drinking 103 pints across 14 countries to check if that's actually true. Ireland won in a landslide. Pints there averaged 74 out of 100. Everywhere else averaged 57. The difference held up even after they adjusted for pub atmosphere, how the pint looked, mouthfeel, and which researcher was drinking. Real 2011 paper in the Journal of Food Science, titled "Does Guinness Travel Well?" So you can see why Zuck hauled a keg over from Dublin. Here's what makes it funnier. The draught Guinness already on tap in San Francisco gets brewed at St. James's Gate in Dublin, the exact brewery that fills the kegs for Temple Bar. One recipe, one source, barrels on a boat either way. The researchers figured the real culprit was the tubing. Irish pubs pour so much Guinness that beer never sits in the line between barrel and tap. At a slow bar in America, your stout has been aging in warm plastic hose for days before it reaches the glass. The barrel makes the trip fine and then gets wrecked in the last three feet. So the one thing that actually makes a pint taste like Dublin is a packed pub drinking fast enough to keep the lines fresh. Good luck fitting that in cargo.