What is Cask Ale?

Posted on August 18th, 2009


Today we’re going to take a look at cask ale, a traditional British style of beer which dates back pretty much to the origin of beer itself. When Shakespeare went to his local pub for a beer, this is how they served it to him. A few weeks ago we explained what bottle-conditioned beer is, which is a helpful starting point as cask ale can be thought of in a lot of ways as bottle-conditioned beer in a cask, which is why it’s sometimes referred to as ‘cask-conditioned.’

The process starts after the beer has been brewed, but remains uncarbonated and unbottled. The beer is loaded into a steel barrel, or cask, similar in appearance to a keg. Additional sugar or wort is added to the cask to restart the fermentation process by the active yeast still in the beer. The yeast goes to work, eating the sugar and expelling CO2 and alcohol. The pressure builds in the cask and the CO2 dissolves into the beer, naturally carbonating it. This natural carbonation also continues to condition the beer’s flavor, smoothing out flavors and mellowing out the hops. Once he receives it from the brewery a pub owner will tap a porous peg in the cask’s hole, known as a ‘bung.’ Excess gas and foam rushes out the bunghole and fining agents are added to settle the yeast to the bottom of the cask. A few days later the bunghole is resealed and the cask-conditioned ale is ready to be served.

Cask Ale Hand Pumps

Cask Ale Hand Pumps

Now the most traditional manner of tapping and serving the cask would simply to have it placed on it’s side, tapped with a spigot and poured into your glass through the wonder of gravity. Due to space, sanitation or various other factors an alternate method was developed long ago. Casks of beer are stored in a pub’s cellar, where it can be kept at the proper temperature (54°F for cask ale) and tap lines are connected leading up to the bar. Because the beer is only naturally carbonated it’s not going to have the pressure to make it up to the bar on its own, unlike modern forced carbonated beer, or soda. To solve this problem a hand pump, akin to the water pump on your grandfather’s farm is used to siphon the beer into a glass. These beer engines, or gravity pumps as they are sometimes known, allow the beer to be poured while preserving the natural carbonation and flavor.

The advantage of cask ale over modern beer is similar to the benefits of bottle-conditioned beer. Because the beer is naturally carbonated by active yeast, it continues to age and condition, becoming more complex and smoother over time. Unlike bottle-conditioned beer though cask ale cannot be aged over a long period of time due to it being exposed to open air. Indeed, cask really should be consumed within a few days of being tapped.

Because of the short shelf life it has and attention that must be paid to it, cask ale began to go out of style in the 1960’s as the bigger brewers began to mimic American style lagers, which are much simpler and economical to store and serve than cask ales. Fortunately British beer drinkers didn’t tolerate this loss of their beer and tradition and the Campaign for Real Ale (CAMRA) was founded in 1971 to preserve this style of beer and the history associated with it. They define ‘real ale’ as “beer brewed from traditional ingredients, matured by secondary fermentation in the container from which it is dispensed, and served without the use of extraneous carbon dioxide,” which basically means cask ale. Although cask ale still struggles in some parts of the UK, thanks to the efforts of CAMRA real ale has come back from the brink of extinction to availability throughout much of the United Kingdom.

Now days you can even find some cask ale at better beer bars and restaurants in America. Next time you see it available do yourself a favor and enjoy a pint of some traditional beer the same way Shakespeare would have. When you do be sure to let us know what you think about it by tweeting your beer and adding the ‘#mybeer’ hashtag.