While the heritage of cold-conditioned beers is not as many-layered as the that of ales, there appears nonetheless to have been a tradition of cold-conditioning some beers going back to the 15th century and it is likely that at least some of these will have been brewed with self-selecting lager yeast.
Of the 200+ small independent breweries found in Oberfranken (Upper Franconia), more than half base their businesses on their version of this local speciality, which is fermented with a lager yeast, conditioned in the brewery cellar for a few weeks. A Kellerbier can be any colour from straw to dark amber and will tend to taste distinctly beery but a bit unrefined. When racked unfiltered into a vertical cask, called a Holzfaß, and served by gravity, without additional carbon dioxide, it is closer to British cask ale than any other style, though a good bar will finish the cask on the day it is broached.
Literally ‘smoke beer’, this now much imitated style was until recent years a speciality of the town of Bamberg, the beer capital of Oberfranken. Some are as subtle as a heavily smoked German ham, while others include but a wisp of woodsmoke against a background of a solid amber or brown lager. The style is a hang-on from the days when malted barley was dried in wood-fired kilns, leaving it with smoky and burnt residues. The arrival of coke ovens enabled maltsters to produce much cleaner malt, enabling the creation of paler, as well as smoke-free beer. For reasons that are unclear, some brewers in Bamberg stayed with the old ways, some still smoking their own malt, while others source theirs from the city’s world-renowned maltsters, Weyermann’s, who now export it internationally.