Making Real Ale at Home
The title of this column may have made you say something like, “Real ale? All my ale is real!” And you are right; Didn’t Descartes say, “I drink it, therefore it’s real?” But there is a specific meaning of the phrase “real ale.” It is a term coined by the British consumer group CAMRA, the Campaign For Real Ale, when it was founded in the early 1970s. And quite simply what they meant was that it is ale which is conditioned with CO2 by a secondary fermentation in the cask from which it is served by gravity or pump, and it must not be driven out of the cask by additional CO2 pressure (or that of any other gas mixture). In short, the term applies not to the brewing of the beer, but to how it is processed after the primary fermentation (yes, I am deliberately using the words ale and beer interchangeably).
What this meant in practice was that the beer could not be chilled, filtered, or pasteurized. It would be kept at cellar temperature, 50–55 °F (10–13 °C), during the secondary fermentation, and be served at that temperature from the cask. One result of this is that the beer would have a relatively low CO2 content. CAMRA generally reckoned this to be about 1 volume, although I suspect the range was more likely 1–1.5 volumes (which compares with 2–3 volumes commonly in use in US brewing. Further, air would be pulled into the cask as the beer was drawn off. Once the cask was broached, the beer would inevitably gradually lose condition, and beer left in the cask would be subject to bacterial infection if not consumed within two or three days.
Why go to all this trouble? What is so special about real ale? Well, quite simply, many drinkers (including professional brewers) think that a good cask of it is beer at its best. Of course that’s a subjective judgement but remember that the beer is at a temperature where all the nuances of flavor and aroma will be released, none of them having been removed by filtration or destroyed by pasteurization. And the CO2 level is low enough to prevent the gas from drowning out other flavors. However, I should point out that when CAMRA came into being what it was fighting was British keg beer, which was chilled, filtered, pasteurized and served cold at two volumes CO2 or more. Such beers in Britain then were intended for the mass market, were usually bland and more expensive than cask-conditioned beer. In the US, craft brewers usually filter their products and serve it at high CO2 levels at temperatures as low as 40–45 °F (4.5–7.2 °C). But their recipes are designed to allow for the effects on flavor of these processes and conditions, so that the beer still has lots of flavor and complexity.
Cask-conditioned beer
This is the classical form of real ale but remember it has a short shelf-life, so you will only want to do this on a limited number of occasions. You will need a cask, and some accessories. These are available, but usually from professional brewing suppliers, rather than those catering to homebrewers. The point about the cask is that it had a bunghole at the bottom of one of the faces and a second hole in the curved side. The second, or shive, hole is sealed with a wooden (or plastic) plug, or shive, whose middle can be knocked out so that a wooden peg or spile can be inserted in it. There are two types of spile — a porous one, which is inserted to control pressure during the secondary fermentation, and a hard one, which is inserted in the shive at the end of fermentation so as to keep the beer in condition. So you will need bungs (in two sizes), hard and soft spiles, and a faucet; to be really fancy you can throw in a hand pump, or beer engine. And of course you will need a cask; stainless steel is the most common material and is better than aluminum or wood for this purpose. All these supplies will run a couple of hundred dollars or so, and much more if you opt for the hand pump.
The best approach I think is to rack the beer after primary fermentation and allow it two or three days in the secondary before racking to the sanitized cask. Do remember to bang home the bung in the bung hole first then fill through the shive hole. Now comes the tricky bit. You need to add enough priming sugar to reach the desired level of conditioning, which is 1–1.5 volumes CO2. How much is the question, for your beer will already contain some of the gas, and you have no way of knowing exactly how much? Well I am going to chicken out here and not make any recommendations, partly because of reason of space, but more importantly because this question was dealt with in some detail by “Mr. Wizard” in the Jan-Feb 2010 issue of BYO (p. 16-18). Author Ashton Lewis points out it that it may be necessary to add fresh yeast at this point, particularly if you used a highly flocculent strain in the primary. You may also wish to add isinglass finings at this point; if so, simply follow the instructions on the packet. You can use gelatin finings, but isinglass is much superior for this purpose.
Once everything is in the cask, hammer home the shive then hold the cask at cellar temperature, if possible, but up to 60 °F (15.6 °C) is okay. After the first 1–2 days, bang out the center of the shive with a screwdriver; you should hear some release of gas when you do so. Insert the porous spile; as soon as no more gas is being evolved, replace it with a hard one. Allow 2–3 days for the beer to fall bright then place the narrow end of the faucet against the center part of the bung. Try to hammer it home with one sharp blow of the mallet; if you do so you will lose only a small amount of beer. Now remove the hard spile and serve your own real ale directly from the faucet. Or if you prefer, attach it via a line to your beer engine and pump the beer out. An advantage of the latter approach is that the pump can be adjusted so that even a relatively flat beer will have a good head of foam. Do remember to replace the hard spile between servings so that the beer does not lose condition.
An alternative approach
You probably have a Corny keg or two for your draft beers, and you can use one of these instead of the cask. You won’t then have to bother with a faucet, bungs and shives. You should proceed as above, but simply seal the keg with its lid during the secondary fermentation. For serving you will need an appropriately sized piece of food grade vinyl tubing; one end attaches to the beer engine inlet, and the other is fitted with a female ball- or pin-lock fitting. When the beer is ready attach the tubing to the “beer out” post, open the pressure relief valve (or loosen the “gas in” post) and pull a pint of real ale from your hand pump.
Another variation
The problem with both the methods mentioned is that the beer has a short life once the cask or keg has been opened to the air. Is there a way round that? Of course, there is! You just use your gas cylinder to drive the beer so that air does not enter as the beer is served. A direct connection can easily raise the gas content above 1.5 volumes, taking it out of our definition of real ale. That can be solved by purchasing (from a professional supplier) a device called a cask breather. This fits into the line between the gas cylinder and the “gas in” post on the keg (it can also be attached to the spile hole in the shive of a cask). It is just a one-way “zero-demand” valve and will only let gas into the keg when beer is drawn out of it. The result is that the pressure above the beer remains the same and in the region we want. This means that you could probably run such a system without the expense of a hand pump; just use a normal picnic tap for serving, and if you are only drawing off a pint or two at a time it should work well enough. CAMRA has proscribed this device, stating that beer delivered with its help is not real ale. This is because they are paranoid that if a CO2 cylinder is connected to the cask, with its valve left open, the beer will become over-carbonated. But I connected an opened gas cylinder, with a gauge pressure of 15 PSI, via a cask breather to a stainless keg of near-flat beer. I left this setup alone for three weeks in which time no gas passed into the beer and it was as flat as when I started!
Yet another variation
From the above it is clear that CAMRA does not understand the physics of the system. If you have a beer containing 1.5 volumes of CO2, and draw off four or five pints, the pressure above the beer is lowered and gas will come out of solution to restore equilibrium. That means that the beer will now contain less than 1.5 volumes (assuming everything is at constant temperature), so you need to apply a little pressure to bring the CO2 level back up. In other words, a short burst of gas from the cylinder after you draw off some beer will not raise the carbonation level of the beer.
That is exactly how I handle my real ale. After secondary fermentation in the keg I connect the gas line to it as I am ready to serve. As long as I can draw off beer through a picnic tap I keep the gas cylinder valve closed; it is only opened for no more than a few minutes when beer does not flow freely from the picnic tap. I set the cylinder gauge at 5 PSI at 50 °F (10 °C); that would make the beer contain 1.5 volumes at that temperature, or 1.66 volumes at 45 °F (7.2 °C), which is my normal serving temperature. At that level the beer is not gassy, and all the flavor nuances still come through. Furthermore, I am not letting in air and the beer does not quickly deteriorate, and will remain in good condition for weeks. Note that you could also do this using mixed gases (CO2/N2), which might, in fact make for better control of CO2 content, but I haven’t put this to the test in my own brewery.
The final variation
This is the simplest technique of all, and one that many homebrewers are already familiar with — bottle-conditioning. It is a method approved by CAMRA, who have persuaded a number of British brewers to offer such beers for sale. I have not properly measured any of these, but would judge from the way they pour that many of these are closer to 2.0 volumes of CO2 than to 1.5! The only point about it is that it is not as easy to achieve a reproducible level of conditioning in the bottle as many people seem to think. Once again, I refer you to Mr. Wizard’s piece for a fuller discussion on this topic.
Closure
I have shown you what real ale is, and also described how you can make it at home according to the strict letter of CAMRA’s law. But I am no great believer in dogma, and I hope I have also shown you that it can be produced by simple techniques, and that you can produce real ale without going to a great deal of extra expense. However, do not let me discourage you from going the whole hog and buying a cask and a beer engine, for there’s something very satisfying about serving your beer exactly the way the pros do it. And to emphasize an earlier point — I give you no recipe for real ale, because the term does not apply to the way it is brewed, but to the methodology of conditioning and serving it.
Finally, some questions as food for thought. Is cask-conditioned beer really better than a beer which has been artificially conditioned with CO2 (and possibly filtered too)? Does gas from a cylinder really make the beer taste differently than gas evolved “naturally” from fermentation? Do we need the term “Real Ale” at all, when the most important question of all is not how the beer is produced, but “Does it taste good?”
