Erin and the DA have a drink of the usual 'Finnerty's' single malt scotch whisky [sic]. Without the 'e', it's the Scottish spelling, with the 'e' it's Irish.
But, Finnerty is a purely Irish name, an ancient one, meaning 'fair snow'. The name originated in the Roscommon area of the Province of Connacht well before the Norman incursion of 1169.
No whiskey, or whisky, distilled and bottled in Scotland would have such an Irish name.