Understanding Real Ale by Ray Daniels
http://www.realalefestival.com/aboutreal.html
You can't read much about English beers without running into the term "real ale." While the subject encompasses more subtle issues, a basic definition can be provided in 35 words or less:
"A name for a draught (or bottled) 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."
The pinnacle of real ale is represented by "cask-conditioned ale"-the usual draft format for serving such products. A cask is a stainless steel (or occasionally wood) barrel which is made to be laid on its side while the beer is served. The term "cask-conditioned" indicates that secondary fermentation of the ale has taken place inside the cask.
A group called the Campaign for Real Ale (CAMRA) in Britain has been working since 1971 to revive and preserve the traditions of "real" and "cask-conditioned" ale. Fortunately, they have been quite successful. Draft bitters and some pale ales may be "real ales" when you drink them in the UK these days. Indeed, a beer that the typical American tourist would describe as "warm and flat" most likely falls into this classification - although real ale adherents would argue that their type of beer is both cool and noticeably carbonated.
The distinction between real ale in its cask form and normal draft from a keg comes as the result of activities by both the brewer and the cellarman. For starters, brewers often "dry hop" their cask ales, adding hop plugs to the beer before the cask is bunged. And, as mentioned above, draft real ales are cask-conditioned-carbonated by secondary fermentation in the cask. Thus when real ale brewers ship their beer, it is actively fermenting. When it arrives at the pub (or at the festival site), such beer requires careful management to ensure that it is served in good condition. As a result of these actions by the brewer, "cellarmanship" is an important skill as it impacts many qualities of the product when it is served. During the entire history of the Real Ale Festival, Steve Hamburg has served as the head cellarman for the event and it is thanks to his efforts that the beer pours clear and tastes great.
When properly served, a good real ale will be transparently clear, with no cloudiness or haze. In addition, it will be at cellar temperature (50 to 57°F) and it will have a subtle but noticeable level of carbonation.
Since real ale is shipped while actively fermenting, clarifying the beer is the greatest challenge. Isinglass finings are commonly added to aid in the clarification of the beer and this is often done by the brewer before shipment. If not, then the cellarman may add the finings himself. Finings help the yeast to settle to the bottom of the cask so that it will clarify more quickly.
To keep from disturbing the resulting yeast sediment, casks must not be moved for several days before serving or during the serving itself. Thus the serving of cask-conditioned ales requires enough properly refrigerated cellar space to keep a substantial inventory in serving position.
The placement of a cask into serving position is called stillaging. In addition to giving the cask a home that it will occupy until empty, the cellarman uses wood chocks to establish a precise forward-tilted position for the cask. This position allows the maximum amount of beer to be served from the cask, while also providing a space below the tap placement where yeast and finings can collect.
Once the ale is stillaged, it will be vented to achieve the proper level of carbonation. A common trait of real ale-and indeed of all bitters and English pale ales-is a much lower level of carbonation than is usually found in American beers. Measured as volumes of CO2 dissolved in one volume of beer, we are accustomed to seeing values of 2.25 to 2.75 in the U.S. As a result of cask conditioning, the typical bitter will have value of just 0.75 to 1.0.
During stillaging, the cask bung or shive will be positioned so that it is pointed at the ceiling. The cellarman hammers a piece of porous wood called a soft spile through a partially drilled hole in the center of the shive. Carbon dioxide (usually mixed with beer foam) escapes from the cask through this porous wood for one or two days as the beer settles. When activity through the soft spile has quieted, it is replaced with a hard spile that retains the remaining carbonation. When the ale is being served, the hard spile will be removed again in order to allow air into the cask.
Sometime during spiling, the cellarman will also tap the cask. This is done by hammering a stainless steel or plastic tap through the keystone located on the flat front surface of the stillaged cask. With the tap in place, the clarity and carbonation of the ale can be directly assessed by dispensing the beer into a glass for inspection. When both clarity and proper condition have been achieved, the cask is ready to be served.
Most beer drinkers know that CO2 pressure is what forces the beer from the bottom of the keg to travel up the hose and into your glass. In bars, beer typically must travel quite a distance from the cooler to the tap head and therefore quite a lot of CO2 pressure must be applied to move the beer. With real ales, no external CO2 pressure is applied to drive the beer. Instead, the beer must be "pumped" up to the bar using a traditional beer engine.
The long handle of the beer engine is used by the bartender to actually draw the beer from the cask, through the hose and out the nozzle. With the hard spile removed, the cask admits air to replace the volume of beer drawn.
At this point, the product reaching the glass is essentially real ale, or more precisely, cask conditioned ale. Purists applaud this method of serving because of the unique flavor characteristics imparted to the beer. Secondary fermentation in the cask ensures that the beer is as fresh as it can possibly be and it certainly doesn't lose any flavor through filtration or pasteurization. In addition, the practice of dry hopping delivers a flavor that is unmatched by nearly any other process.
