At the B----O American Brasserie in Baltimore, bartender and cocktail historian Brendan Dorr pulls out bottles of rum for a world-class tutorial and taste test.Rum has many uses in refreshing cocktails, but, as Dan discovers, some of the aged brands are best sipped neat.Also on this show, Brendan Dorr talks about — and offers us a taste of — the South American cousin of rum, cacha\u231\ua, the basis of Brazil's national drink, the Caipirinha.