"Free soda" and "free beer" are analogous, if that helps. Or, since it seems to need explaining, the point is that "beer" is not one thing with one recipe and

"Free soda" and "free beer" are analogous, if that helps. Or, since it seems to need explaining, the point is that "beer" is not one thing with one recipe and if somebody offers you "free beer" it is pretty obviously a specific kind and batch of beer.