Cask Ale
Today, we are used to having ice cold, crystal clear, fizzy beer dispensed from a pressurized keg on demand, whether in a bar or at home. But not that long ago, most of the beer brewed around the world was dispensed from a cask, served lightly carbonated with live yeast and at cellar temperatures — cool, but not cold. Whilst that time has largely passed, cask beer culture remains alive and well in Britain, and others around the world are starting to catch on to the joys of cask ale too. In North America, a small but growing number of breweries are serving cask ale at their tap rooms, and a number of beer festivals dedicated to it are held every year. With this growing interest in cask beer — something I have spent my entire adult life drinking and my professional brewing career making — I wanted to share with you how to make it at home, how to look after it, and how to serve it.
Why Cask Ale?
I am not here to wax lyrical about how amazing cask beer is; there are many writers who have already done that far more eloquently than I ever could, and at great length. But I will say this; if you have never had a British ale dispensed from a cask, you have missed a key element of the experience. Most of the beer styles that are British in origin — bitter, mild, porter, stout, brown ale, pale ale, IPA, etc. — were originally created by brewers who dispensed them from casks. Because of this, they were designed and crafted to be enjoyed at their best when served lightly carbonated, on live yeast at 52–55 °F (11–13 °C). Don’t get me wrong, I have had some very good ales dispensed from kegs, but there is something about them that just doesn’t live up to the cask ales I know and love. To me, traditional British beer styles are at their most authentic and enjoyable when served from a cask. If you’ve never tried one, you really should.
Different Types of Cask
In the UK, almost every brewery produces at least some cask beer, with a number producing nothing else. The casks they use are usually made from either stainless steel or food-grade plastic, with each having its advantages and disadvantages. Steel casks are very robust and durable; they are more scratch-resistant, which prevents spoilage microbes getting a foothold; and it is much easier to keep them cool. Plastic casks, on the other hand, are much lighter and cheaper, but are more prone to damage.
As well as different materials, casks come in different sizes with most commercial cask breweries using the following three kinds:
• Pins: 4.5 imperial gallons (5.4 U.S. gallons/20.4 L)
• Firkins (also known as “nines”: 9 imperial gallons (10.8 U.S. gallons/
40.9 L)
• Kilderkins (also known as “eighteens”: 18 imperial gallons (21.6 U.S. gallons/81.8 L)
For the purposes of homebrewing, pins will be the best option for most people as they are the closest in size to the typical homebrewery setup of around 5 gallons (19 L), although you may have to make a slightly larger batch to fill one. However, there’s no reason you couldn’t also use a firkin if you brew larger batches or want to make two batches in short succession. I would not recommend kilderkins for homebrewers, not just because of the practicalities of filling one, but also because they weigh in at around 200 pounds (90 kg) when full, making them very difficult to move without special equipment.
Anatomy of a Cask
Even modern steel and plastic casks are shaped like traditional wooden barrels, with two flat ends and rounded sides. The flat top end is known as the “head” and there you should find a small hole called a “keyhole.” This is closed with a plastic or wooden stopper called a “keystone” and is also the hole through which the tap is inserted when dispensing. Around the head you will see a low ring called the “chime,” which helps to protect the head and keyhole when the barrel is being moved around, and you will often find the name of the brewery the cask belongs to etched onto the outside of the chime. The curved belly of the cask is called the “bilge,” in the middle of which you’ll find the “bunghole.” This is larger than the keyhole and is used to both clean and fill the cask. The bunghole is plugged with a plastic or wooden stopper called a “shive.”
How to Clean and Fill a Cask
In order to clean a cask you must first remove the keystone, carefully levering it out with a metal tool such as a large, flathead screwdriver, or better yet, a special tool called a shive extractor. With plastic casks, extra care must be taken whilst doing this to ensure you don’t damage the lip underneath the keystone.
Remove the shive by inserting a heavy-duty screwdriver or shive extractor through the hole in the middle of it and levering it out. Doing this with the cask stood upright and with you sitting on it makes this much easier, as it prevents the cask from rolling around. Position the cask with the
bunghole over a drain or bucket and allow any remaining beer dregs to drain out. Tip it upright and spray sanitizer around the keyhole, take a sanitized keystone and tap it about halfway into the keyhole with a mallet.
Position the cask with the bunghole pointing upwards. You need to clean off any residue from the inside and the best way to do this at home is with a pressure washer, if you have one. Insert the pressure washer nozzle through the bunghole and spray all the internal surfaces. Drain out the water and use a flashlight to check that all visible dirt has been removed.
Pour about 1–2 quarts (1–2 L) of sanitizer solution in through the bunghole, and seal up the bunghole with a shive. With steel casks, you should only need to tap it in with your hand to seal it, allowing you to easily remove it again, but with plastic casks, you will need to knock the shive all the way in, meaning you will have to sacrifice it to remove it. Roll the cask in all directions to ensure the sanitizer comes into contact with every surface. Repeat a few times, then remove the shive and drain out the sanitizer. Rinse if necessary. Use a mallet to knock the keystone all the way in, until it is flush with the keyhole. Now you are ready to fill your cask.
The first step in filling a cask is priming it with sugar. For a pin cask, dissolve 1 oz. (28 g, or 2.25 tablespoons) white sugar in 1⁄3 cup (80 mL) of boiled water and pour it in the bunghole. For a firkin cask, double these quantities. Do not be tempted to increase the amount of sugar to provide additional carbonation; I’ve seen several casks blow their shives and it makes an almighty mess!
If you wish to dry hop your beer, add them at this stage just before racking starts. If using pellets, I strongly recommend using a hop filter in your tap later on; if you are using whole leaf hops, this shouldn’t be necessary. Next, attach a sanitized hose to the tap on your fermenter that reaches all the way to the bottom of the cask when inserted through the bunghole. Open the tap on your fermenter and allow the beer to gently flow into your cask under gravity. While the cask is filling, you may wish to add isinglass to help ensure your ale is crystal clear on dispense — use around 1 cup for a pin cask and 2 cups for a firkin cask. Do not add isinglass with the priming sugar, as the heat from the boiled water will stop it from working. Alternatively, embrace the haze and don’t use finings at all! Fill the cask to the very brim with your beer. Fobbing (foaming) may make it difficult to see where the level of the beer is, in which case keep filling until the liquid (rather than foam) is just starting to overflow. Finally, seal up your cask with a shive, knocking it in with a mallet until it is flush. Rinse off any beer on the outside of the cask and leave it at around 68 °F (20 °C) for at least two weeks to condition before serving.
How to Tap a Cask
So you’ve brewed your beer, cleaned your cask, filled it and it’s been conditioning nicely for a couple weeks, so I’m sure you’re eager to break into that beauty and get a taste of that authentic British cask ale, right? Well, hold your horses there buddy, good things come to those who wait.
First, you need to let your cask settle. So, 24 hours before you want to serve your beer, you need to put your cask in position where you want to serve it. Ideally it should be in a cradle called a “stillage” that holds it in place and tips it slightly forward. But if that’s not an option, place it on a sturdy table with heavy objects on either side to stop it from rolling, and a suitable block of wood propping it up at the back so that the head is pointing slightly downwards. It should be oriented with the shive pointing upwards and the keystone pointing towards you. During the next 24 hours, any yeast and precipitated protein floating in your beer should settle to the bottom of the bilge, especially if you have used finings. It should also be kept at a constant 52–55 °F (11-13 °C) if possible, so an unheated basement is ideal.
After 24 hours in that position, you’re ready to tap. People have slightly different ways of doing this, but here’s the way I do it. First, spray the shive and keystone with sanitizer. You will then need a small wooden or plastic peg called a “hard spile.” Holding this with a pair of pliers at the blunt end, sanitize it, then hold it just above the center of the shive. With a hard blow with a mallet, knock it into the shive. Thanks to the pliers, you should have about half an inch (1.25 cm) poking out, and you won’t have broken your fingers. Leaving the hard spile in place, take your sanitized tap and, holding it by the rotating faucet section, line it up with the center of the keystone. This next step is important — make sure the tap is closed and do not hold it by the long shaft or you will break your hand. Being careful of your fingers, knock the tap into the keystone with a mallet. It may take a number of strikes and beer may spurt out around the tap as you are doing this — don’t panic, just keep hitting it until the spurting stops. Depending on the type of tap you have, you may now need to screw a down-spout on to the end. Now, place a glass under the tap, open it and once the beer is flowing, use your pliers to pull out the hard spile. If you like, you can replace the hard spile by gently placing a soft spile in the hole left in the shive, which will allow air in, but will prevent insects and other things getting in.
If you wish to dispense your cask ale from a beer engine, all you will need to do next is clean out the dispensing hose and dispensing pump with a suitable cleaning agent, as recommended by your equipment supplier. Then attach the hose to the tap of the cask with a 3⁄4-inch cask nut (or whatever size is appropriate for your tap) and a hose tail suitable for your hose (ideally secured with a hosepipe clip), then open the tap and draw the beer through with the pump.
Congratulations! You just tapped your first cask of real ale! Now that you are enjoying that delicious beer, here comes the bad news — you have about 4–5 days to drink it all before it starts turning into vinegar. This is the unfortunate downside of cask ale; once you start letting air into your cask, the beer inside it has a limited lifespan. It’s the main reason they have largely been replaced by kegs, which work by keeping air out. You can help to prolong it a little by tapping the hard spile back into the shive between drinking sessions, effectively sealing it again, but you’re still on a ticking clock. Now, if you’re running a bar, having a party, or just have a lot of drinking buddies, that shouldn’t be a problem; but if you’re trying to get through that thing on your own, it may be an issue. Thankfully, there are some alternative ways of producing cask ale at home that reduce this issue.
Alternatives to Casks
There are a couple of alternatives to actual casks that will achieve a similar outcome to cask ale. The first is a pressure barrel, which is a popular option amongst British homebrewers. This is essentially a plastic barrel with a built-in tap and large screw-top lid that can hold a certain degree of pressure from carbonation and comes in 2.6-gallon (10-L) or 6-gallon (23-L) sizes. These can essentially be primed, fined, and filled in exactly the same way as casks, adjusting for size, and then sealed up by screwing the top on. With a built-in tap, you also don’t need to go through the potentially messy business of tapping it. Many also come with a valve at the top that allows you to attach a small carbon dioxide canister. This is not to push the beer out, as with a keg, but simply to fill the space created at the top of the barrel as the beer is dispensed, preventing oxygen from getting in and spoiling your beer. Hardcore real ale enthusiasts consider this to be cheating, but it’s a personal choice.
Another option is to split your batch into several smaller steel “mini casks.” These usually hold 1.3 gallons (5 L) and are sometimes erroneously called “mini kegs,” even though they have more in common with casks than kegs. Prime each one with 0.25 oz. (7 g) of sugar dissolved in as small an amount of boiled water as you can get away with, fill as you would with a cask, and add about 2.4 oz. (71 mL) of isinglass, if you wish. The rubber bung supplied with it should be sanitized in boiling water, which also helps to soften the rubber, making it easier to push in and seal the mini cask. This bung also acts as the vent, much like the shive on a real cask, allowing air in so that beer can flow out from the built-in tap. This means they have a similar lifespan to real casks once opened. But with a much smaller volume, you can finish them off much more quickly. It is possible to reuse these mini casks, and you can find videos on YouTube instructing you how to do this.
Making Cask Ale
Given that this is a magazine about making your own beer at home, it would be pretty remiss of me not to talk about how to actually make ale for casks. This is pretty challenging, given that it covers so many beer styles, but I will provide what advice I can in general terms. British cask ale brewers tend to use a single temperature infusion mash in the region of 149–154 °F (65–68 °C) and use high-quality British base malts, such as Maris Otter and Golden Promise. Obviously the specialty malts and adjuncts you use will depend on the exact beer style you’re making, but should also be British in origin if you want to be authentic. Goldings, Fuggle, and Challenger might be the obvious hops to use in a British style beer, but the UK now produces at least 31 other hop varieties on a commercial scale, many of which are also suitable in traditional ales. Don’t be afraid to try something new. I have even used German varieties occasionally, as they share a similarly herbal, earthy aromatic profile. A 60–90 minute boil is typical and the use of copper finings, such as protofloc or Irish moss, is very common.
When it comes to yeast, selecting the right kind can make a huge difference. A true British ale strain is necessary to get the right flavor, but for cask ale you also need a yeast that is going to flocculate well to make sure it settles out nicely in the barrel. In terms of dried yeast, Nottingham and S-04 produce great tasting beer and both flocculate really well. OYL-006 and OYL-016 are good options from Omega Yeast, and from White Labs I would suggest WLP-002, WLP-006 or WLP-030, or from Wyeast 1318, 1335, or 1968.
Your primary fermentation should take place at the recommended temperature for your yeast strain, which for most British yeasts is around 68 °F (20 °C). I suggest fermenting your ale until it reaches a stable gravity, which should take 5–10 days. Once that has happened, add a silica sol fining agent and reduce the temperature to around 41 °F (5 °C) or below if you can, as this will help to settle the yeast and precipitate out any proteins that can cause a haze in your beer. Hold it there for two days, then you are ready to rack into your cask.
Cask ale can be a tricky beast; it requires special equipment and is not to everyone’s taste, but there are plenty of people like me who love it and see it as a true art form within the brewing world. And I’m not alone — there are several major organizations in the UK dedicated to preserving it, including the Campaign for Real Ale (CAMRA), and Cask Marque, which ensures pubs serve cask ale to the highest possible standard. So I hope that with my advice, you’ll be able to enjoy the sort of beers I have known and loved all my adult life and come to share my passion for them.
Ship’s Cat Dark Mild
(5 gallons/19 L*, all-grain)
OG = 1.035 FG = 1.010
IBU = 24 SRM = 24 ABV = 3.2%
It is rare for me to brew the exact same recipe twice; I tend to make tweaks and adjustments even to ones I like. But I brew this recipe every late spring in time for session drinking over the summer
because I love it so much.
*Please note that this recipe is for 5 gallons (19 L), as is standard for BYO.
If you want to fill a pin-sized cask, I suggest increasing the quantities by 10%.
If you want to fill a pressure barrel, increase the quantities by 20%.
Ingredients
5.7 lbs. (2.6 kg) Maris Otter pale ale malt
1 lb. (454 g) medium crystal malt (60 °L)
7.6 oz. (215 g) chocolate malt (425 °L)
4.7 AAU First Gold hops (60 min.) (0.5 oz./14 g at 9.5% alpha acids)
3.6 AAU Tettnang hops (15 min.) (1.1 oz./31 g at 3.4% alpha acids)
1⁄2 tsp. (0.6 g) Irish moss
Silica sol
7.2 fl. oz. (213 mL) isinglass (optional)
SafAle S-04 or your favorite English ale yeast
0.9 oz. (25 g) sugar
Step by step
Mash all of the malt at around 152 °F (67 °C) for one hour. Collect 6 gallons (23 L) of wort in the kettle and boil for one hour, adding the First Gold hops after 15 minutes, and then the Tettnang hops and Irish moss after 45 minutes. At the end of the boil, chill to 68 °F (20 °C) and then transfer to your fermenter and pitch the yeast. After five days, add the silica sol fining according to the manufacturer’s instructions and then chill to 41 °F (5 °C) or below for two days. If filling a single container (e.g. a pin cask or pressure barrel), dissolve the sugar in the smallest amount of boiled water as you can, add this to the container and then rack the beer onto it. Add the isinglass (if using for the purpose of clarification) directly to the container while the beer is being racked. Seal the container and condition at 68 °F (20 °C) for at least two weeks before serving.
Ship’s Cat Dark Mild
(5 gallons/19 L*, extract with grains)
OG = 1.035 FG = 1.010
IBU = 24 SRM = 24 ABV = 3.2%
*Please note that this recipe is for 5 gallons (19 L), as is standard for BYO.
If you want to fill a pin-sized cask, I suggest increasing the quantities by 10%.
If you want to fill a pressure barrel,
increase the quantities by 20%.
Ingredients
4 lbs. (1.8 kg) Maris Otter liquid malt extract
1 lb. (454 g) medium crystal malt (60 °L)
8 oz. (230 g) chocolate malt (425 °L)
4.7 AAU First Gold hops (60 min.) (0.5 oz./14 g at 9.5% alpha acids)
3.6 AAU Tettnang hops (15 min.) (1.1 oz./31 g at 3.4% alpha acids)
1⁄2 tsp. (0.6 g) Irish moss
Silica sol
7.2 fl. oz. (213 mL) isinglass (optional)
SafAle S-04 or your favorite English ale yeast
0.9 oz. (25 g) sugar
Step by step
Place caramel and chocolate malt into a steeping bag and submerge in 6 gallons (23 L) of water at or near 155 °F (68 °C). After 20 minutes of steeping, remove the grain bag, then bring the wort up to a boil. When boil is achieved, take the kettle off the flame and add the extract while stirring. Once extract is fully dissolved return to the heat source and boil for 60 minutes, adding the hops as indicated.
At the end of the boil, chill to 68 °F (20 °C) and then transfer to your fermenter and pitch the yeast. After five days, add the silica sol fining according to the manufacturer’s instructions and then chill to 41 °F (5 °C) or below for two days. If filling a single container (e.g. a pin cask or pressure barrel), dissolve the sugar in the smallest amount of boiled water as you can, add this to the container and then rack the beer onto it. Add the isinglass (if using for the purpose of clarification) directly to the container while the beer is being racked. Seal the container and condition at 68 °F (20 °C) for at least two weeks before serving.
Tips for success:
Anyone who is vegan will want to know that isinglass is obtained from bladders of fish. Sadly, isinglass is pretty essential if people want their beer to be crystal clear in 24 hours. As much as I wish silica sol could do this on its own, experience tells me that it simply doesn’t (I’m actually vegan and have spent the last three years trying to find a good way of replacing isinglass in casks and so far I have failed). The addition of isinglass is optional but not using it may result in hazy beer.
Copper Clad Best Bitter
(5 gallons/19 L*, all-grain)
OG = 1.040 FG = 1.008
IBU = 29 SRM = 11 ABV = 4.1%
Every self-respecting cask ale pub in the UK will have a best bitter on the bar. This recipe uses Endeavour, a modern British hop variety, to provide a refreshing, light, and fruity character to this most traditional of ale styles.
*Please note that this recipe is for 5 gallons (19 L), as is standard for BYO. If you want to fill a pin-sized cask, I suggest increasing the quantities by 10%. If you want to fill a pressure barrel, increase the quantities by 20%
Ingredients
7.5 lbs. (3.4 kg) British pale ale malt
8 oz. (230 g) medium crystal malt (60 °L)
4 oz. (110 g) amber malt (27 °L)
1.4 oz. (40 g) chocolate malt (425 °L)
3.7 AAU Challenger hops (60 min.) (0.4 oz./12 g at 9% alpha acids)
1.5 AAU Endeavour hops (30 min.) (0.15 oz./4.3 at 9.8% alpha acids)
11.4 AAU Endeavour hops (5 min.) (1.2 oz./33 at 9.8% alpha acids)
1⁄2 tsp. (0.6 g) Irish moss
Silica sol
7.2 fl. oz. (213 mL) isinglass (optional)
SafAle S-04 or your favorite English ale yeast
0.9 oz. (25 g) sugar
Step by step
Mash all of the malts at 150 °F (65.5 °C) for one hour. Collect ~6 gallons (23 L) of wort in the kettle and boil for one hour, adding the Challenger hops as soon as it starts boiling. After 30 minutes, add the first (and smaller) lot of Endeavour hops, then the Irish moss after a further 15 minutes. Add the final lot of Endeavour hops 5 minutes before the end of the boil.
At the end of the boil chill to 68 °F (20 °C) and then transfer to your fermenter. Aerate well and pitch the yeast. After five days, add the silica sol fining according to the manufacturer’s instructions and then chill to 41 °F (5 °C) or below for two days. If filling a single container (e.g. a pin cask or pressure barrel), dissolve the sugar in the smallest amount of boiled water as you can, add this to the container and then rack the beer onto it. Add the isinglass (if using for the purpose of clarification) directly to the container while the beer is being racked. Seal the container and condition at 68 °F (20 °C) for at least two weeks before serving.
Copper Clad Best Bitter
(5 gallons/19 L*, extract with grains)
OG = 1.040 FG = 1.008
IBU = 29 SRM = 10 ABV = 4.1%
*Please note that this recipe is for 5 gallons (19 L), as is standard for BYO.
If you want to fill a pin-sized cask, I suggest increasing the quantities by 10%.
If you want to fill a pressure barrel, increase the quantities by 20%.
Ingredients
5 lbs. (2.3 kg) Maris Otter liquid malt extract
8 oz. (230 g) medium crystal malt (60 °L)
1.4 oz. (40 g) chocolate malt (425 °L)
3.7 AAU Challenger hops (60 min.) (0.4 oz./12 g at 9% alpha acids)
1.5 AAU Endeavour hops (30 min.) (0.15 oz./4.3 at 9.8% alpha acids)
11.4 AAU Endeavour hops (5 min.) (1.2 oz./33 at 9.8% alpha acids)
1⁄2 tsp. (0.6 g) Irish moss
Silica sol
7.2 fl. oz. (213 mL) isinglass (optional)
SafAle S-04 or your favorite English ale yeast
0.9 oz. (25 g) sugar
Step by step
Place caramel and chocolate malt into a steeping bag and submerge in 6 gallons (23 L) of water at or near 155 °F (68 °C). After 20 minutes of steeping, remove the grain bag, then bring the wort up to a boil. When boil is achieved, take the kettle off the flame and add the extract while stirring. Once extract is fully dissolved return to the heat source and boil for 60 minutes, adding the hops as indicated in the recipe.
At the end of the boil, chill to 68 °F (20 °C) and then transfer to your fermenter and pitch the yeast. After five days, add the silica sol fining according to the manufacturer’s instructions and then chill to 41 °F (5 °C) or below for two days. If filling a single container (e.g. a pin cask or pressure barrel), dissolve the sugar in the smallest amount of boiled water as you can, add this to the container and then rack the beer onto it. Add the isinglass (if using for the purpose of clarification) directly to the container while the beer is being racked. Seal the container and condition at 68 °F (20 °C) for at least two weeks before serving.
Tips for success:
Anyone who is vegan will want to know that isinglass is obtained from bladders of fish. Sadly, isinglass is pretty essential if people want their beer to be crystal clear in 24 hours. As much as I wish silica sol could do this on its own, experience tells me that it simply doesn’t (I’m actually vegan and have spent the last three years trying to find a good way of replacing isinglass in casks and so far I have failed). The addition of isinglass is optional but not using it may result in hazy beer.
