You have gotten many decent replies already. I think one thing that is missing is that the phrase talks about "free as in free beer". So it is not a statement t

You have gotten many decent replies already. I think one thing that is missing is that the phrase talks about "free as in free beer". So it is not a statement that beer in general is free, it is a clarification that we want the meaning of "free" as in the phrase "free beer". In other words: At no cost. ("gratis") This is in contrast to "free" as in "free speech", which is about freedom/liberty. ("libre")