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 DRAUGHT 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.
The brief life of a cask-conditioned ale. Beer is a fragile drink. Alcohol, which acts as a preservative in wines and spirits and some beers, is typically lower in the majority of ales and lagers and are best consumed when they are as fresh as possible. Cask-conditioned ale, which is as close to beer straight from the brewery that you can possibly get, is doubly fragile. Once a cask is tapped, it is exposed to air, which along with UV rays is one of beer’s fiercest enemies, and so the longer a cask remains on tap, the more likely it is to spoil. Devices designed to minimize the beer’s exposure to air, known as cask-breathers, can lengthen the time a beer might remain on tap, but where cask ale is concerned, the Golden Rule remains: The fresher, the better! Help us spread the awareness and availability of fresh cask-conditioned ale, use the hash tag #oncask when drinking or tapping cask beer.