Not exactly a beer style but a technique that can be applied to any style, Unfiltered Beer refers to any beer that is intentionally served with yeast remaining in the cask, keg, or bottle.
Most mass-produced beers are filtered to give them a bright clarity. Most home brewers do not filter their beer, although many take pains during the beer brewing process to reduce the amount of yeast or sediment remaining in the beer.
The GABF recognizes a specialty style for unfiltered beer.
GABF Style Listings
Cellared or Unfiltered Ale
|These are typically classic ale styles packaged and/or served intentionally with low to moderate amounts of yeast. Pale Ale, Bitter, Brown Ale, Porter, ESB or any other ale style may be entered into this subcategory. Unfiltered versions of other ale styles that are normally filtered (alt for example) may also be entered in this subcategory. Products may be filtered and redosed with yeast in the package, bottle conditioned, or packaged unfiltered or loosely filtered. These beers may or may not portray a yeasty mouthfeel depending on the amount of yeast contained in the package and dispensed during pouring. They will most likely not be clear, and may appear slightly hazy to very cloudy. Yeast flavor and aroma should be low to medium but not overpowering the balance and character of malt and hops. Low to moderately low levels of yeast-generated sulfur containing compounds may or may not be apparent in aroma and flavor, and low levels of acetaldehyde or other volatiles normally scrubbed during fermentation may or may not be apparent. Dry Hopping is acceptable. Head retention may not be optimal. The brewer must provide the classic style on which the entry is based to allow for accurate judging. Beer entries not accompanied by this information will be at a disadvantage during judging.
Original Gravity (ºPlato): Varies with style