Enjoy the Real Thing: Cask-Conditioned Ale
Homebrewers are the luckiest people. They get to make their own beer however they want it — and store it and serve it however they want it, too. If you are a dyed-in-the-wool English ale fanatic, you can naturally condition your beer in the keg and drink a pretty darn reasonable facsimile of the real deal: cask-conditioned ale.
Some of us are content to force-carbonate beer, saving time and reducing sediment. Others are a bit more obsessive about the real-ale experience and choose to start a secondary fermentation in the keg to stay truer to the English-ale style.
Then there are the real die-hards, those who cask condition their beer and build beer engines to pull it from the keg by hand. Now that’s taking homebrew to the next level.
Real Ale History
Just what is “real ale,” anyway? Back before the days of mass-produced beer and when breweries would not dream of filtering and force-carbonating their product, all the ale sold in the great pubs of England was “real.” Meaning cask conditioned. “Real ale” is a relatively new term, brought to the forefront by the efforts of the English grassroots political group to whom every beer lover owes a great debt, the Campaign for Real Ale (CAMRA).
Not so very long ago in England, the big brewers were swallowing up all the little cottage breweries and converting their productions to “modern” standards. That meant filtration, pasteurization, and carbonating prior to kegging. It was a simple way to speed things up, get a handle on the process, and ensure consistency and control. CAMRA members would substitute the words “dead” and “boring” in the last sentence. But more on that later.
To understand British real ale you have to understand the way beer is made and sold in Britain. Unlike the United States, with its post-Prohibition “three-tier” distribution system, England still uses the tied-house system. That is, most of the pubs are owned by the breweries, and the people who work in the pubs are, in effect, brewery employees.
This is key to the real-ale system, because real ale depends on the “cellarman,” the person who manages beer in the cellar of the pub and makes it ready for drinking.
In a real-ale system the beer is delivered to the pub while it is still working. It’s not ready to drink and needs some maturation. Put simply, on the brewery end this means racking the beer to casks with a priming of sugar and sometimes new yeast, or simply racking it to barrels before the primary fermentation has finished.
Either way, the beer undergoes a secondary ferment in the barrel, a lot like homebrew in the bottle. The kegs are stopped airtight until they reach the pub. There, the cellarman takes over the process and will either keep the keg sealed or vent it, depending on the age of the beer and level of conditioning desired.
It’s a complex job and not for someone who couldn’t care less. The cellarman has to understand his beer and be willing to dote over it, keeping the barrels in the correct position and at the right temperature, adding fining agents when necessary, dry hopping if the customers demand. The cellarman applies liberal doses of tender loving care until the beer comes into proper condition. Sounds like a dream job, doesn’t it?
Again, the brewery plays a key role here. Most real-ale houses in England can call on the team of conditioning experts at the brewery if trouble arises or when advice is needed. If the beer won’t “drop bright” for instance and remains cloudy in the keg. If off-flavors develop. If the beer is flat. When you need them, this team of specialists will make way to your establishment to see what the matter is.
Come to think of it, that sounds like a dream job, too. But the point here is that a lot of care and attention is needed to keep cask-conditioned beer going. And that’s the reason the practice all but died out in England by the 1970s. That was until a few enterprising souls founded CAMRA and began putting pressure on the breweries to keep the real ale flowing. A favorite trick of the group is holding a public funeral whenever a real ale brewery is slated for closure or takeover.
CAMRA has gone on to publish newsletters, pub guides, and other materials. And CAMRA gets credit for starting the Great British Beer Festival. Its efforts have resulted in a resurgence of real ale production and consumption in England. England is enjoying its own beer renaissance with demand for real ale at its highest in decades.
Defining Real Ale
CAMRA has created standards for real ale and is having an effect on the beer industry — not too unlike what’s happening with homebrewing in America. With homebrewers defining styles so specifically for the sake of judging and competition, it helps to set standards for styles within the professional community as well.
Briefly, real ale is defined as ale that has undergone a secondary ferment in the barrel. It is served at proper temperature — not too cold — and is dispensed without the use of gas under pressure. Real ale is tapped either by beer engine or by gravity. The ale is not filtered or pasteurized.
The English cask is designed to handle this set of circumstances elegantly. Real wood casks have gone by the wayside in much of England, although a few brewers and pubs still employ them. Today’s cask is made of stainless steel. But it is nothing like an American stainless beer keg.
For starters the cask is barrel-shaped, similar in shape to a Golden Gate keg; it is fatter in the middle than on the ends. Because the cask spends its days lying on its side, the sediment resulting from the secondary ferment ends up settling into the fat part around the middle.
When the cask is sitting in its cradle, known as the stillage, at the top is the shive hole. That’s the hole through which beer, finings, or hops are added to the barrel, either in the brewery or the pub.
The shive hole is designed to accommodate a wooden or plastic plug called a shive. The shive is drilled with a smaller hole to accommodate the spile, a smaller plug made of hard or soft wood, depending on the needs of the cellarman. The soft spile is porous and allows the cask to breathe. The hard spile tightly stops the opening.
The cask is tapped through the head end, which is on the side when the cask is sitting in the stillage. The other major difference between English casks and American kegs is that British casks have no internal plumbing. All American beer kegs and soda tanks have internal dip tubes that allow the liquid to be dispensed from the bottom. The English cask is designed to allow the yeast and hop sediment, called “lees,” to sit undisturbed as the beer is pulled. Passing the beer over the lees on the way to the glass contributes to the character of cask-conditioned ale.
Cask-conditioned ale is unique. Particularly when hand pulled by a beer engine, it is smooth, creamy, and often more complex than its contemporary, fully carbonated counterparts. Because the beer is alive with yeast and is fermenting, many unique flavor and aroma compounds are produced in cask ale that are absent in anything pasteurized or filtered.
Homebrewers employ a version of the process every time they bottle. Bottle-conditioned beer exhibits some of the same characteristics as cask-conditioned beer. That’s one reason well made homebrew is often more interesting than even microbrewed beer from the supermarket. The yeast is still viable in the bottle.
Most homebrewers have made a batch or two that tasted a little off after two weeks in the bottle. But after a month or six weeks, sometimes that “strange brew” can take on a new personality and become a premium beer. The cask-ale brewer and cellarman use the nature of fermentation to their advantage — sealing this keg, venting that one, letting it mature just to the point of perfection.
A Superior Process?
Is cask conditioning better than other ways of handling beer after it is brewed? There’s a question that, like religion and politics, might be best avoided in mixed company. It is clearly a matter of opinion. Those who would walk over hot coals for real ale will say nothing else can compare to cask-conditioned ale. Other folks think differently.
Garrett Oliver, brewmaster at Brooklyn Brewery, New York, says you can’t say one method is better than another, because it’s a matter of style and taste.
“Cask ale is not necessarily better, but it is definitely different,” Oliver says. “Cask-conditioned ale is a style in and of itself. It’s entirely different from ale served any other way. It’s unique. Cask conditioning produces a fragile subtlety that cannot be achieved any other way.”
When Oliver was with the Manhattan Brewing Co., he supplied authentic cask-conditioned ale to a few clients who had the facilities and expertise to handle it. Brooklyn started out strictly as a contract brewer. However, it recently built its own brewhouse (in Brooklyn, of course). From the new facility Oliver plans to once again add cask-conditioned ales to his portfolio.
A common perception in the homebrew community is that bottle or cask-conditioned beer is better simply because it’s naturally carbonated. That’s only half the story.
Oliver reminds homebrewers that “conditioning” and “carbonation” do not mean the same thing. “Conditioning involves a lot more than just carbonation,” he says. “That’s only one element of the cask-conditioning process. What’s as important is the fact that secondary fermentation takes place. That produces a whole new set of flavors, aromas, and other characteristics in the beer that are absent in beer conditioned by other means. For example many esters that would normally be vented out during fermentation are trapped in the cask and dissolved into the beer, affecting overall flavor and aroma.”
The Ale Sublime
Those who love real ale will argue that it’s the best beer on god’s green earth. But again, many factors come into play.
John Bovit, president of Yards Brewing Co. in Philadelphia, says real ale is so wonderful because it’s served at its absolute peak. “Freshness is key,” Bovit says. “Especially when you allow the primary fermentation to finish in the cask, the freshness really comes through and contributes to better flavor. You drink the beer when it’s at its best. Even a stronger style, like IPA or barleywine, that requires more aging will taste better cask conditioned.”
Bovit produces only naturally conditioned beer from his three-barrel brewery in the Manayunk section of Philadelphia. “We don’t even own any force-carbonation equipment. When we want to force carbonate something, usually for testing, we put it in a Cornelius keg, chill, and shake, just like homebrewers do,” Bovit says.
According to Bovit the differences are particularly apparent when the ale is hand pulled using a beer engine. “Hand-pumped ale has a fuller, creamier mouthfeel that makes the ale much smoother than beer dispensed the usual way. The difference is night and day between hand-pulled and CO2 dispensed,” he says.
Bovit says another reason he loves real ale is the fact that it is not always the same. “I tell brewers real ale should always be great but it does not have to be the same every time. I think that’s an important aspect of the style, and it makes the style more approachable for the average homebrewer.” Real ale is a living, organic beverage, and it is reasonable to expect variations from batch to batch.
Getting Down to Brass Tacks
If you want to brew up a batch of cask ale, start with a good recipe. Any English style will fit the bill. Bitter and IPA are especially tasty when cask-conditioned and hand pulled.
While you are waiting for the primary fermentation to finish, you should modify your soda keg. Thedip tube normally goes to about one-quarter inch from the bottom of the keg. If you leave it this way, all the yeast will be drawn out of the keg with the first few pints and you will lose the effect of the beer passing over the lees on the way to your pint glass.
Hence, you should remove an inch or two of dip tube to allow a deeper level of yeast sediment to remain at the bottom of your keg while you drink it.
If you want to take it one step further, you could remove the dip tube completely, then build a rack for the soda keg allowing it to lay on its side during conditioning. You could then dispense with gravity and come pretty close to authentic cask ale. However, maintaining serving temperature will be tricky under these circumstances, because you will not be able to stand the keg up in the fridge.
A compromise is to condition the keg on its side, then gently stand it up to chill to serving temperature. Much of the sediment created will stick to the wall of the keg and stay put, even after the keg is left upright.
Because most American bars are not equipped to handle English casks, brewers who make real ale are faced with similar packaging challenges. At Yards as at most other micros producing real ale, the Hoff-Stevens keg is the compromise vessel. In a Hoff-Stevens keg the dip tube does not go to the very bottom of the vessel, hence yeast sediment is left to continue to work its magic as the beer is consumed.
“We started selling our beer as ‘cask conditioned,’ but a number of customers called us to the mat, noticing the beer was kegged, not casked. Now we refer to it as ‘keg’ conditioned and that seems to be more technically correct, especially for our clients who are not using beer engines,” Bovit says.
Get Rid of That Yeast
Yards’ brewer Brandon Greenwood says that an important step in the brewing process is often skipped by homebrewers: skimming the yeast. “Every English brewer removes yeast from the top of the fermenting beer. In fact the Burton Union and Yorkshire Square systems were devised to automatically remove yeast, to keep the beer from being handled,” he says.
Greenwood knows of what he speaks. He earned his brewing credentials in the United Kingdom at Heriot-Watt University in Scotland. “You should remove yeast at high kraeusen, before it starts falling back into the primary. This usually occurs two to three days into the ferment. You do this to slow things down and prevent the beer from fermenting out too quickly. It also prevents off-flavors coming from too many dead yeast cells in the primary,” he says.
Greenwood suggests using a stainless spoon or perhaps a Pyrex measuring cup. “Scrub it well with lots of elbow grease and strong detergent — something like TSP — and sanitize completely before dipping it in your beer,” he says.
Priming
Once primary is complete, the goal, as previously stated, is to start a secondary ferment in the keg. You have two choices here, one a bit more manageable than the other.
At Yards Greenwood likes to catch the primary ferment at just the right point, racking when the gravity is about two points higher than terminal. To use this traditional method you have to know your recipe and know your yeast. If you don’t have a good idea what your terminal gravity will be, you could miss the mark in the carbonation level.
“For the sake of argument, say you know your terminal will be 1.010. You should keg at around 1.012,” Greenwood explains. “You can count on roughly 0.6 volumes of CO2 for each point of specific gravity above terminal at kegging time,” he says.
In this case kegging at 1.012 would condition the beer to around 1.2 volumes. That’s nice and low for an English ale meant to be hand pulled. The action of the beer engine injects room air into the beer as it hits the glass through a tiny showerhead, known as a sparkler. This puts a nice, creamy head on top of the softly carbonated ale.
If you are going to use CO2 to dispense your beer, you will not be able to take advantage of the sparkler and should condition to a higher carbonation level so the beer will not taste flat. Yards conditions to around 2.5 volumes for its regular draft accounts. “That’s still lower than the average micro, around 2.75,” says Bovit.
“Catching” the beer at the right gravity is tricky, particularly if it hits the mark in the middle of the night or on a day when no one is around. For this reason it’s usually easier to let the beer ferment out, then prime with added sugar.
Priming sugar can be corn sugar, dry malt extract, or fresh wort. Corn sugar is the easiest to deal with and also a traditional priming agent in England. That’s the method outlined here.
Beer carbonates more readily in a keg than in a bottle because the keg has less headspace volume compared to five gallons of beer packaged in bottles, so you use significantly less priming sugar in the keg, nowhere near the three-quarters cup standard for bottling. For low-level carbonation, use one-quarter cup of corn sugar. For medium carbonation, use one-third cup. You can go as high as one-half cup but at this level, you might be approaching carbonation too high for true English style.
The proper level of priming in your brewery will be learned through trial and error. As with primary fermentation, it will be affected greatly by the nature of your yeast and temperature at which you hold the keg during the conditioning phase.
Generally speaking you want to keep the keg near the same temperature you used for primary fermentation; 55° to 65° F is perfect. Again, it depends on the yeast. You also need to guard against the kegs getting too cold, or fermentation will shut down and you will end up with “dead” beer.
You might be thinking, wouldn’t an automatic relief valve make this step a little more foolproof? Right you are. You can buy a pressure gauge ready to clip onto your keg to monitor the pressure. Braukunst in Carlton, Minn., sells an automatic valve. “Our V-7 adjustable valve adjusts over a range of three to 50 pounds per square inch,” says Cliff Tanner, Braukunst’s principal. “We use it on the outlet of our F-36, which is a stainless disconnect attached to a 30-psi pressure gauge and a manual valve. That alone works for cask conditioning, but the addition of the relief valve automates the process.”
Fining
Fining agents are protein based. When you add finings to the keg, proteins in your beer that cause cloudiness will tend to latch on to the fining agent protein and, hopefully, settle out.
The traditional English fining agent is isinglass, a protein derived from the air bladders of fish. Prepared isinglass is available from any good homebrew supplier. It’s very easy to use. Simply add it at priming time. You can also use gelatin to fine naturally conditioned beer. Simply mix one envelope of Knox unflavored gelatin in a cup of cool water or beer. Stir well until dissolved, then heat to a gentle simmer to sanitize. Mix this in along with your priming sugar.
Leave Beer at Fermenting Temperature
How long you leave the keg alone for conditioning will also vary from brewery to brewery, ale to ale. Your taste buds are your best guide. You have to take off your homebrewer hat and put on your cellarman hat. Generally, you should start tasting the beer after five to seven days in the keg. If the carbonation and flavor is to your liking, start pulling pints. If not, let it work a little longer.
True cask ale is vented to the outside air to allow the beer engine to work — or when tapping by gravity. To vent your keg, simply attach a gas-in connector by itself, without any hose or regulator. If you are going to pull the ale by engine, it’s a good idea to let the keg vent for a day or so before you start pulling pints. This allows the beer to settle down and will help to prevent excess foaming in the glass.
If you are worried about bringing in dust and contaminants, attach a short piece of gas hose to the connector and stuff the end with cotton. This will have a similar effect of a soft spile, letting CO2 out and filtering the room air that enters the keg when you pump it.
Oh No, Oxidation!
Speaking of air, what about the dreaded oxidation? You are right to be worried about that.
Oxidation is a reality of true cask ale. That’s a good part of the reason English brewers tried to abandon the style back in the 1960s. It’s a significant reason real ale is so difficult to handle in the pub setting. Real ale is meant to be consumed quickly. Real-ale heads are so excited about real ale because it changes over time, even as it’s being consumed. The first stages of oxidation will contribute to the overall character of the brew. But in time the quality of the beer will decrease as air is left to sit on top of the beer.
There’s hope. Homebrewers can take a cue from real-ale pub managers who use a device called a “bleeder.” It is set to replace the beer in the keg with a blanket of inert CO2, but not under pressure. The bleeder simply squirts CO2 into the cask as the beer is drawn. Since CO2 is heavier than air, it sits atop the beer without escaping through the vent.
Although CAMRA frowns on this practice, it is a reasonable way to preserve real ale that is not being consumed fast enough.
At home you should purge the keg of air at the end of the night. Open the top a crack, then let some CO2 flow in for a minute or so. It will sink to the beer and push the air out of the open top. Seal the top again and your beer will stay fresh until your next engine session.
This leads to an important point about homebrew and beer engines. Hand pulling beer is inconvenient for one or two glasses of beer. It’s best to use a beer engine when you have a decent number of beer lovers around, to make the effort worthwhile.
Have fun. And get brewing.
