Cask Ale or Real Ale
Cask means container. Put simply, cask ale is the original method of storing and serving beer. Not having concave bottoms or straight sides, the barrel or cask design allows sediment to be retained in the cask and they all contained unfiltered, unpasteurized beer. In order to get the beer out of a keg and into a customer’s glass, it can be forced out with gas pressure, although if air or gas at low pressure is admitted to the top of the keg it can also be dispensed using a traditional hand pump at the bar. By the early 1970s most beer in Britain was keg beer, filtered, pasteurized and artificially carbonated. This change was largely driven by the customer's dislike of sediment in his beer. However, most British brewers used carbon dioxide for dispensing keg beers. This led to beers containing more dissolved gas in the glass than the traditional ale and to a consumer demand for a return to these ales. However, in Ireland where stout was dominant, the use of a mixture of carbon dioxide and nitrogen for dispensing prevented the beer from becoming over carbonated. Some of the last remaining natural beers in the world were about to disappear forever. Though rare examples of natural beers could still be found in the farmhouse beers of Northern Europe and the maize beers of South America for example, in essence the last great stronghold of natural beer was about to be wiped out. And that’s when the Campaign for Real Ale (CAMRA) stepped in in Britain to save what they came to term Real Ale.
In the early 1970s CAMRA coined the term ‘real ale' to make it easy for people to differentiate between the bland processed beers being pushed by the big brewers and the traditional beers whose very existence was under threat.
Many pubs and brewers use the term to describe their beers, but, just to keep you confused, they are also called cask beers, cask-conditioned ales or even real beer! In the pub the huge majority of real ales are served using traditional hand-pulls, rather than through modern fonts, but there are some exceptions to this, so if in any doubt, just ask.
Real ale is a natural product brewed using traditional ingredients and left to mature in the cask (container) from which it is served in the pub through a process called secondary fermentation. It is this process which makes real ale unique amongst beers and develops the wonderful tastes and aromas which processed beers can never provide.
Why isn't all beer real?
Real ale is a natural, living product. By its nature this means it has a limited shelf life and needs to be looked after with care in the pub cellar and kept at a certain temperature to enable it to mature and bring out its full flavors for the drinker to enjoy.
Brewery-conditioned, or keg, beer has a longer shelf life as it is not a living product. Basically, after the beer has finished fermentation in the brewery and has been conditioned, it is chilled and filtered to remove all the yeast and then it is pasteurized to make it sterile. This is then put in a sealed container, called a keg, ready to be sent to the pub.
The problem is that removing the yeast and ‘killing off' the product through pasteurization also removes a great deal of the taste and aroma associated with real ale.
Cask ale has finings. Finings are substances that are usually added at or near the completion of the processing of wine, beer and various nonalcoholic juice beverages. Their purpose is for removal of organic compounds; to either improve clarity or adjust flavor/aroma. Unless they form a stable bottom sediment in the final container, the spent finings are usually discarded from the beverage along with the target compounds that they capture. added which drag the yeast to the bottom; when the finings have cleared the beer it is said to have “dropped bright” and the beer will look clear rather than cloudy. But if a beer has been filtered, or has been cleared of yeast by using finings, and then "racked"—transferred to another container—this is “bright” or re-racked beer. Bright beer is essentially unpasteurized beer which has been cleared of yeast and placed in a different container. It no longer sits on the yeast. As such, strictly speaking, it is not real ale because it cannot continue to ferment in the container in which it now finds itself. A more useful definition would recognize that, since bright racking and drinking quickly is technically no different to filling up a glass from the original cask, the important elements of real ale are the secondary fermentation, that it is free from carbon dioxide, unfiltered, not lagered, etc. Putting beer into another container before your glass for ease of quick use, does not change any of this.
The fundamental distinction between real and other ales is that the yeast is still present and living in the container from which the real ale is served, although it will have settled to the bottom and is usually not poured into the glass. Because the yeast is still alive, a slow process of fermentation continues in the cask or bottle on the way to the consumer, allowing the beer to retain its freshness. Another distinction is that real ale should be served without the aid of added carbon dioxide, or "top pressure" as it is commonly known. Common dispensing methods are the handpump, or "by gravity" direct from the cask. Electric pumps are occasionally seen, especially in the Midlands and Scotland.
When a cask has been tapped, the beer starts to come into contact with oxygen—and a beer in contact with oxygen has a limited life. The stronger the beer the longer it will survive, but for most ales with an ABV in the low 4% region, three days is typical. If the pub doesn’t have a high turnover, or if a beer is not popular, such as dark milds, three days will not be enough to sell all the beer in the cask. A cask breather allows a small amount of CO2 to replace the oxygen in the cask. Not enough CO2 to enter the beer or push it up to the bar—that’s “top pressure”—but just enough “blanket pressure” to keep the beer fresh tasting for longer. Just long enough, in fact, for the landlord to sell all the beer in the cask.
The use of cask breathers is considered “extraneous carbon dioxide”, so CAMRA does not endorse this method.
Cask ale brewing starts the same as that of keg beer. The same brew run could be used to make cask, keg, and bottled beer. The difference is what happens after the primary fermentation is finished and the beer has been left to condition. While pasteurized keg and bottled beers are then subjected to filtering and flash heating, the beer for the cask is simply placed in the cask in its natural state. Finings, such as isinglass or Irish moss, are placed in the cask to assist removing the yeast and clear the beer. Extra hops and sugar may also be added. The cask is sealed and sent off to the pub. In this state it is like a bottle-conditioned beer and, like bottle-conditioned beers, the beer will continue to develop for a certain period of time. Also like bottle-conditioned beers, the length of time the beer can last in the cask will depend on the nature of the beer itself: strong, dark beers can last for months; light, delicate beers need to be tapped and sold quickly. Stronger beers may also need longer to settle and mature. Some pubs have been known to keep very strong beers in a sealed cask for up to a year to allow them to fully develop.
When the landlord feels the beer has settled, and he is ready to serve it, he will knock a soft spile. A spile is a small wooden peg used to control the flow of carbon dioxide out of a cask of ale.) into the shive. A shive is a wooden or plastic fitting used in ale casks. It is found on the curved side of the cask, arranged so that when the cask is on its side and the keystone is at the lowest part of the rim, the shive will be the highest point of the cask. The hole in that part of the cask is used for two purposes. Firstly, it is used for cleaning out and then refilling the cask, which requires a large hole. Once the cask arrives at its destination, the hole is used to control the amount of carbon dioxide present in the container, which requires a small hole. The shive is effectively an adaptor that reconciles these conflicting requirements. It is a wooden disk, larger than a keystone, that fits in the hole in the cask and has a smaller hole in its centre.
The major difference in appearance between a keg and a cask is the shive. A keg does not have a shive on the side. The majority of casks these days are metal, and at first glance look just like kegs. Even though there are still some wooden casks around, these are rare; in fact there are more plastic kegs around than wooden ones. Plastic casks are increasing in popularity because they are cheaper to buy and lighter to carry, though they don’t last as long. Beer casks come in a number of sizes, but by far the most common in the pub trade are those of 9 gallons (72 pints or roughly 41 liters) which is known as a Firkin and 18 gallons (144 pints or roughly 83 litres) known as a Kilderkin. The kilderkin is an old English unit of volume equal to half a barrel or two firkins. It was used as standard size for brewery casks. (These are imperial gallons, equal to 1.201 US gallons each.) A Firkin is an old English unit of volume. The name is derived from the Middle Dutch word vierdekijn, which means fourth, i.e. a fourth of a full-size barrel.
| 1 kilderkin | = ½ barrel |
| = 2 firkins | |
| = 18 imperial gallons | |
| = 81.82962 liters | |
| ≈2.890 cubic feet |
The soft spile in the shive allows gas to vent off. This can be seen by the bubbles foaming around the spile. The landlord will periodically check the bubbles by wiping the spile clean and then watching to see how fast the bubbles reform. There still has to be some life in the beer otherwise it really will taste flat, but too much life and the beer will taste hard or fizzy. When the beer is judged to be ready, the landlord will replace the soft spile with a hard one (which doesn’t allow air in or gas out) and let the beer settle for 24 hours. He will also knock a tap into the end of the cask. This might simply be a tap if the cask is stored behind the bar. The beer will then be served simply under gravity pressure: turn on the tap, and the beer comes out. But if the cask is in the cellar, the beer needs to travel via tubes, or beer lines, and be pumped up to the bar area.
A “beer engine” or handpump is used to siphon the beer upstairs. The beer engine is a half-pint (sometimes a 1/4 pint), airtight piston chamber; pulling down on the handle raises the piston which drags up a half pint of beer. When a cask is first tapped into the beer engine, or after the lines have been washed through, the pump needs to be pulled several times to clear the lines of air or water. The line will continue to hold beer, which will tend to go stale overnight, so the first beer pulled through will be bad beer, and this will be simply thrown away. Most pubs will pull through at least a pint of beer on each beer engine before they open, while others will wait for the first order of beer on that pump before pulling through. Experienced bar staff will serve a pint with two long, smooth, slow pulls of the pump handle, plus a short third just to make sure the glass is full.
If you peek over the bar at the spout from which the beer emerges you may notice a small flip tap and a short spout; this is normal. If you notice the spout is quite long with a hairpin curve this is a swan-neck which is designed to force the beer into the glass, agitating it so that a head is created and some flavor is reduced.
In some pubs a small device or cap is fitted to the end of the spout rather like a sprinkler at the end of a hose pipe. The device is known as a "sparkler". Like the sprinkler at the end of a hose, this can be twisted to regulate the flow of the beer. When the sparkler is tight, the beer is severely agitated resulting in a large head but a significant loss of flavor and mouthfeel. This is most common in the North of England. Many drinkers in the North prefer their beer this way; it is softer and creamier with less bitterness. Drinkers in the South tend to prefer their beer with a touch more bitterness, and a slightly harder mouthfeel.
Those seeking authentic real ale should be aware that some pubs will disguise a keg beer by having some form of imitation pump handle on the bar. If the bar staff have merely turned on a tap, or are just resting their hand on a very small handle with no pump action, then this is a keg beer. Exceptions are some pubs in the North which use electric pumps or the few remaining pubs in Scotland that use traditional air-pressure founts on cask ale. Asking the staff will usually clarify this.
The famous warm temperature of cask beer in the summer months doesn’t apply all that often these days with temperature control units in pub cellars and the beer lines running through coolers. In fact, some pubs will run the cask ale lines through the lager chiller in order to get the beer below the maximum temperature required by Cask Marque, so a cask ale may end up as cold as a keg lager. This is rarely a good thing, because ale requires a cool rather than a cold temperature to reveal all its flavours. It can also disguise a far worse situation in which, although the beer in the glass is cold, the contents of the cask are rapidly turning to vinegar in the heat. Moderate cooling around the beer lines to maintain their temperature against the warmth of the bar is usually beneficial, but the beer must be stored at an appropriate temperature to begin with. In a well run pub the cask ale will be served at the appropriate temperature: cool, but not chilled.
The aroma of cask ale is fresher and more wholesome than keg beer. But the aroma of cask ale does not have the stored up impact of bottled beers; cask beer is beer which has already been exposed to the air for a couple of days, so there is not going to be a big impact when it is simply transferred to your glass. Typically the aroma will be released when it has warmed up slightly, and that will probably be when you are near the bottom of the glass. And no prickly oxygen tent aroma that comes with the extra CO2 used to give keg beer its “life”. All you will smell is natural, fresh beer—and the difference is like sniffing artificial fruit flavorings compared to sniffing the fresh fruit. The artificial flavorings will be pleasant and intense, while the fresh fruit will be very delicate, sometimes slipping away. Aroma, it has to be admitted, is not one of the high points of cask ale, but if you prefer scents that are delicate, exquisite, fresh and natural, then you will enjoy the bouquet of cask ale.
The flavor of cask ale is similar to the aroma in that it is delicate and fresh, but unlike many bottled beers the flavor of cask ale is more noticeable than the aroma. The aroma is often very slight, even non-existent at first, but the flavor makes up for that. Obviously the intensity of flavor depends on the beer style—a session bitter is not going to slap your taste buds in the way that a golden ale or imperial stout will—but a cask ale in good condition will have the flavors defined rather than muddled. CO2 bubbles in themselves have little flavor, so a mass of those bursting against your tongue will prevent the beer itself from making contact. With cask ale there is little carbonation, so more of the flavor compounds will be in contact with your taste buds. You should be able to clearly note the fruity sweetness up front, the balance in the middle and the bitterness in the finish. The flavor profile of a cask ale is much more noticeable than a keg or bottled beer.
The most important aspect of cask ale is the mouthfeel. It should not be fizzy. If your beer is fizzy then it’s either a keg beer or it’s a cask ale that’s been put on too soon. If you are used to carbonated drinks—keg beer, bottled beer, sparkling water, cola, etc.—the mouthfeel of a cask ale may seem a little strange—even flat or boring—at first. There are some people who don’t even notice the mouthfeel. If they are just drinking the beer without paying attention—maybe they are chatting away, or maybe they are trying to catch the aroma or flavor of this cask ale they have heard so much about—the mouthfeel will pass them by.