For many, this circular mark might go completely unnoticed. As a recent social media post that sparked a lot of conversation put it, “Most people will go their whole lives without ever knowing what the circular indent on the side of the milk jug is for.”
There are some interesting theories out there. One Facebook user, Cory Anderson, thought “the milk is going bad when it pops out.” Another social media user believed it might have something to do with the carton expanding in cold weather. Andrew Serpico, also on Facebook, suggested that “the bubble gives the milk somewhere to expand to so it won’t bust the carton if you freeze it.”
