Anecdotal sources suggest that a dot on beer can bottoms indicates freshness levels. They are there to tell the distributors if the beer is fresh enough to still be sold. Beer companies go around to stores that sell their products and check to make sure there are no old or "stale" beers on the shelves anymore.
The truth is that the Nordson Ink-Dot I.D. system identifies which spray paint machine (for creating the labels) coats each beer can on a factory line system.
A dot of ink is applied on the bottom of each can as it enters a machine.
A different color of ink is used for each machine so the source of any imperfect coatings can be instantly identified and repaired or replaced, rather than shutting down the entire line of machines.
It’s not hard to walk into your favorite bottle shop, grocery store, or gas station to pick up some beer. But, what shape is that beer in? Is it fresh or has it been sitting there for six months, two years, or since before prohibition? Check out some tips on how to buy beer like a pro — with some advice from the pros at Brewprof.com.