History of Kellerbier
It is a version of German lager originating in Franconia, Bavaria and dates to the very beginnings of lagering in the latter half of the Middle Ages. Lacking any type of refrigeration technology, brewer’s would brew their beer during the cool months of the year and then lager them in caves. These caves acted like natural cellars allowing the beer to remain at stable, cool temperature for the length of their slow maturation.
Kellerbier translates to “cellar beer,” an obvious reference to the cooler temperatures the beer is brewed and conditioned under. But the brewers also used a peculiar set of conditioning techniques that set it apart from the other lager styles.
It is unpasteurized and traditionally conditioned in an oak cask that was open to the environment through an unplugged bug hole. This allowed any CO2 from secondary fermentation to escape, and anything in the immediate environment in which, even in the relatively stable environment of a cave, no doubt created nuanced differences in the Kellerbier.
The bung hole was only sealed for shipping and the beer was served from the same cask it had matured in. So, the resulting pour would have been minimally, if at all carbonated, and quite cloudy with yeast and nutrients that neither settled out, nor been filtered out.
There are a couple even more obscure sub-styles of Kellerbier. Zwickelbier is basically a younger, weaker, less hop-forward, and usually darker version of the same “Keller” song. It isn’t allowed the same maturation time as Kellerbier.
In fact, right before fermentation is complete the bung hole is sealed giving the beer decent carbonation and as soon as the yeast has finished its work, it is served. Its name is taken from the German name for a beer sampling device that is hung on the outside of fermentation takes, the Zwickel.
The other sub-style, Zoiglbier, is pretty hard to tell apart from Zwickelbier. Just like Zwickelbeir it is less hoppy, weaker, darker, more carbonated, and served younger. It may be slightly less carbonated, maybe a little darker in color, but it would be pretty hard to tell the two styles apart.
The pale-style Kellerbier, outlined below in “Characteristics,” is a modern adaption of the original darker Franconian style. It is more along the lines of a Helles than a Märzen, and is more popular, at least outside Franconia, than the traditional style.
Kellerbier in all its forms has survived in large part because of Franconian love. It still enjoys vast popularity in its place of origin, which, no doubt has saved it from total extinction.
Amber Kellerbier
This is the guidelines for the historical Amber-style Kellerbier set by the BJCP Style Committee. The amber Kellerbier is a close representation of the original style brewed and lagered in caves. The below details are a summary of what you should expect when tasting, buying or brewing this beer style.
Appearance:
Color will be deep gold to a reddish-amber. Haze will depend on the beer’s age and can vary from slightly cloudy to clear. The size and condition of the head will depend on whether it is served from a cask or not. Cask serving will result in little carbonation and not much of a head, otherwise expect a small off-white creamy head.
Aroma:
Malt aromas will be of medium intensity playing a range of rich bready, toasty notes with tones of bread crust, but any roasty, biscuit-like, or caramel would be out of place. Peppery and spicy qualities are provided by the hops at medium-low to moderate levels. Slight diacetyl presence possible. Very low green apple and med-low sulfur and/or other notes created by the yeast are possible.
Mouthfeel:
Not sweet or cloying, but a medium body with a smooth creamy texture pushed. Carbonation will again vary by type of serving and can range from medium to none at all.
Taste:
Front of the palate may find some malt sweetness along with a complex array of toasted bread notes. Any roast or caramel is inappropriate to the style. Hop flavor appears peppery, spicy, and herbal, with a range from low to med-high. Bitterness is moderate to med-high. Balance can show off either the hops or the malt, but the finish should not be sweet. Rather it should be medium-dry to dry, with a bitter edge. Possible very low diacetyl, along with very low yeasty flavors, such as green apple. Aftertaste is malty.