They are flying because this story’s resident farmer/inventor/mad-man Yershmin (possibly the same guy who ran out the bar, or a different guy with the same name) decided to invent something new, something that wouldn’t be used on his farm. So, being good friends with Jeff, he decided to invent something really special for his friend…without telling him…He managed to implant a chip into some of Jeff’s beer bottles that either
a) Gave them a personality
b) Made them dance the Irish Jig
c) Made them fly on their own
Obviously the implant then made them fly, but is that the end of this new race of beer bottles’ talent?