Firstly and very importantly, the Guinness must be served on draft. Drinking from the bottle or a can does not allow for the full experience. Into an official Guinness tulip-shaped pint and at a 45-degree angle it must be filled up to the harp above the Guinness logo (about two thirds of the way full).
But scientists claim to have settled the score once and for all: Guinness tastes better in Ireland than anywhere else. It took 103 in 71 different pubs where factors such as pub ambience, Guinness appearance, flavour, and aftertaste were all considered.