I never heard of Mabel either, unless "Give me a Black Label Mabel" was a Carling Black Label commercial.

In college I remember picking up a case of "Frankenmuth" beer for a camping trip because it was 'way cheap. That was horrible stuff - we got what we paid for.

Nearly all oddball-brand American beers are made by the major brewers, and that was true even before so many mergers happened. The thing about cheap American brews is that they're made with a lot of corn syrup substituting for barley malt. Corn is a whole lot cheaper, and it makes the beer "lighter" in color and taste.

Most all American beers have a lot of corn syrup, and the cheap brands have even more of it. Corn syrup is the same as corn sugar, and homebrewers pretty much quit making "sugar beers" a long time ago.