Just back from BCN, I stayed in a small town near the airport called Sant Boi de Llobregat. Most bars offer only Estrella Damm and other variants. Until that is I found a small off licence and bar called Tot Begut, well stocked with international and Spanish craft beers. They had 5 taps and probably 100 bottles. Non beer drinkers a well catered for with some excellent wines.
Beer on tap included Punk IPA, Fyne Hurricane Jack, unfiltered Pilsner Urquell and a cracking Russian Imperial Stout by Calavera a local brewery. San Boi is on bus line 77 from the airport and train L8 from Pl Espanya. Well worth a visit