WHAT IS CASK ALE?
In the early days of draught beer, before metal kegs, CO2 tanks or refrigerated coolers, there was cask-conditioned ale. Also known as cask ale or, sometimes, real ale. Unlike most beer, which is delivered from the brewery in a finished state, cask-conditioned ale does not complete its fermenting until days or even moments before it is delivered to the drinker, with a small amount of fermentation continuing in the cask from which the beer will be poured. Before tapping, a vent is opened in the top of the cask and the extra gas is allowed to escape, which is why cask ale is less carbonated than other beer. As a final step ‘finings’ are added to encourage the yeast to sink to the bottom, where it will remain undisturbed while the beer is poured. Your finished pint may be a bit cloudy, but should be mildly carbonated, slightly chilled and fresh and vibrant in taste.
CASK V.S DRAFT BEER
Cask-conditioned ale is unfiltered, unpasteurized, naturally carbonated beer that continues to ferment in the barrel until close to the time it is served. The beer is poured without the use of any external gasses and is, as a rule, served at cellar temperatures (about 10 - 14°C) and at low carbonation levels. Ideally cask-conditioned ale should be consumed within a window of 2-3 days from the time it is tapped. Although most frequently associated with low-strength ale styles like best bitter, pale ale, ESB and mild, but can also be higher-strength barley wines and Imperial stouts. The process of making and serving cask-conditioned ale demands care and attention from the bar owner as well as the brewer, since part of the beer development actually takes place in the bar itself.