At last Simpsons fans know how Duff beer became Duff beer. In his new book Springfield Confidential, longtime writer, producer and prior showrunner of The Simpsons Mike Reiss dispenses plenty of inside information on the longest-running network television show in America. Some of that intel includes the back stories on a number of character names — and product names. There’s been a myth circulating that Duff Beer, Homer Simpson’s favorite cold one, is named after Guns N’ Roses bassist Duff McKagan, based on McKagan’s own statements on the matter in his memoir It’s So Easy: And Other Lies.