This modern reel was composed by fiddler Brendan McGlinchey, though it is sometimes mistakenly credited to Charlie Lennon. According to a story recounted by Juergen Gier, McGlinchey composed the tune while attending a fleadh, tionól, or similar traditional music gathering. During the event, he stayed in the caravan of a man named Sweeney, with whom he shared not only accommodations but also a fondness for buttermilk—an amusing detail that may have inspired the tune’s name.