Netflix House of Guinness: The two theories that suggest Guinness is actually WelshThe most famous drink in Ireland is Guinness, but there are two theories that suggest the black stuff is actually Welsh, not IrishView 2 Images Ireland's national drink may actually be Welsh (Image: Hulton Archive)Netflix's new series about the Guinness empire is proving extremely popular on the streaming platform. ‌Theory number oneWelsh historian Deiniol ap Dafydd argues that Guinness cannot be certain where the first cask of porter originated. Mr ap Dafydd believes it wouldn't have made commercial sense for porter to be shipped all the way from London – especially considering the route to Holyhead passed through Eryri [Snowdonia]. As young Arthur Guinness grew older, he assumed his father's role, and the beverage was gaining significant popularity among influential dignitaries at the palace. In fact, Mr Guinness signed a nine thousand year lease on St James’s Gate Brewery in Dublin.