Cask ale, also known as real ale, is a traditional type of beer made with natural ingredients and served directly from the vessel in which it was fermented. It is allowed to mature naturally, and it does not include any injections of additional carbon dioxide.
Cask Ale is not filtered or pasteurized and is still active on the yeast. The result is a unique brew that cannot be artificially recreated. Most examples of cask ale will be soft, round, and gently carbonated, with a more complex aroma and flavor than factory-produced brews.
They are always pulled manually, usually from a hand pump. Most beer styles can be made as cask ale, but the technique is best suited to traditional beer styles such as bitter, pale ale, stouts, and porters. Cask Ale is mainly found in Great Britain, and most pubs will have at least one cask ale on tap.