I am a big fan of schwarzbier, but there are relatively few on the market. The most common one is Köstritzer, a beer from the former East Germany that has become widely available since the brewery was purchased by Bittburger.
Sam Adams now has a Black Lager. I have not had a Köstritzer in some time, so it is hard to compare them (note to self: buy some Köstritzer and arrange for a taste test). My immediate reaction to the Sam Adams was that it is probably better, and that is saying something. Very rich malt, perfectly black color (some alleged shwarzbiers don’t quite live up to the name), and just enough hoppiness to balance the malt. (This is a style that should not be particularly hoppy.)
My standards of the style are U Fleku (available only at the brewpub in Prague), Herold Dark (apparently no longer being imported from the Czech Republic, at least to the West Coast), and Rio Salado Thunderhead (Tempe, Arizona, never sold in California). While I have not tasted U Fleku’s brew in almost exactly a year, or the others in a longer time, I would say that the Sam Adams may be a notch below this trio of stars of the style. But very good.
Oh, no, say it is not so: Rio Salado may have ceased operation. Can anyone confirm, or–please–deny this?
Try Pivovarsky Dum next time you are in Prague – some strange novelty beers but also very good standard and dark beers. You can also get some pretty good schwarzbier at some brew pubs in Berlin. Prost!