Heritage Brewing: The Unions Sets

Used since the 1800s, the “union set” – also sometimes called a “Burton Union” – is a fermentation system. It uses a row of wooden barrels suspended in place with a wooden or metal frame. Older barrels are used, so that they do not impart any flavour to the finished beer. 

The barrels are evenly spaced and fitted with a bottom valve that runs through to a trough. Each barrel has a cooling coil to help control fermentation. The vessels are linked together with side pipes so that the wort can move evenly through them. Swan neck pipes from the top of each barrel open out onto a top trough, which is positioned above the barrels on a slight slant. 

Fresh wort runs into the system. It already contains yeast and is actively fermenting. The action of the yeast forces it out of the swan necks and into the top trough. That trough fills with the yeasty foam, known as barm, while any wort that comes through with it trickles down the trough and runs back into the casks to continue its fermentation. 

Gradually, healthy yeast is collected at the top of the system, which allows the beer in the barrels to become bright. Yeast from the top trough can be used again and the fully fermented beer is dropped into the bottom trough and collected ready for packaging or further conditioning. 

Walker filed a patent for his invention, #7658, on 31st May 1838, entitled: “Apparatus to be used in cleansing beer or other fermented liquors.” However, his casks were not linked together – it would be a few more years before the fully mature, framed and linked system that we know today was developed. 

The historical record suggests that Walker’s work was an evolution, not just of carriage cask, but also several other inventions. Mr R W Dickinson of the Albany Brewery, Kent Road, first hit upon the idea of laying the casks on their side and using a pipe to feed the frothing yeast into a tub set above it. Dickinson’s “apparatus for clearing beer” was awarded a silver medal by the Society for the Encouragement of Arts, Manufactures and Commerce (now the RSA) in 1823. Dickinson’s work may in turn have drawn from other innovations, like R Shannon’s “Brewer’s Gyle Tun and BarmSafe”, described in his 1805 publication, A Practical Treatise on Brewing, Distilling and Rectification. 

The union system is labour intensive, Barnard observed. The barrels need continual maintenance and cleaning is difficult. The time and expense involved in running the union sets saw them gradually decommissioned. Breweries employed fewer coopers and developments in technology saw the introduction of stainless steel brewing kits that were easier to clean and maintain. 

Sadly, even when the union was at its height, brewing in Burton had already begun a slow decline. The London brewers, who had flocked to the town to take advantage of its water chemistry around the time the union method was introduced, discovered that they could “Burtonise” their water at home by adding salts. Cheaper transport costs also encouraged larger brewers to find new, more conveniently situated, pale ale contractors. This is a great simplification, but essentially the town had lost its allure. Most of the great breweries there sold up, merged or simply went out of business. 

Burton was not out of the game, however, and much of its focus shifted to lager production. Molson Coors still brews out of Burton to this day, as does Carlsberg Britvic. Until recently, they were the Carlsberg Marston’s Brewing Company (CMBC) – then Marston’s decided to get out of the brewing game altogether, and instead focus on their pub estate. Marston’s had been the last bastion of the union sets in Burton. 

“It was like Mark was handing over six of his kids to us,” head brewer Rob Lovatt recalls. “Each one was numbered, so we’ve got 10 to 15. Mark renumbered them up for us, stained them and then did all the heads and painted them. It was a massive part of his life, maintaining these sorts of things.” 

Once in situ, cooper Mark helped to put a cleaning regime in place. They are sprayballed with hot water every other day, then once every week or two they are filled up with water to soak. There are no chemical cleaners involved, and the team has been trained how to watch for any potential issues with the wood. 

Empire Process Engineers Ltd was the firm who relocated the union to Thornbridge. They had already worked alongside Marston’s Brewery for more than 25 years, supporting them with on-site pipework installations and tank/vessel manufacture. 

“It was with a heavy heart that we were asked to look at relocating the famous union sets in 2024 after working around them for so many years,” said Empire Director, Lee McCarthy. “But we were also pleased that a new home had been found for such an important part of brewing heritage. 

“The responsibility of moving such an iconic part of brewing heritage was compounded by the need to dismantle the set in as sympathetic a manner as possible while also cutting it down to facilitate removal and transportation.” 

“The barrels all contain different concentrations of yeast. It’s these individual variations across the barrels that we think are giving the beers a unique character. 

“We’ve abandoned using the bottom troughs to run the beer into the racking tank, as there was too much potential for oxygen pick up. We had a steel manifold made that we can connect to the bottom taps, so we can run the beer out of the barrels and pump it across for racking easily.” 

Thornbridge has released a collaboration brew made on the union approximately every two months, and they have all been quick to sell out. They’ve been brewing a range of beer styles to learn as much as possible about how the system works. 

But sadly, there were issues behind the scenes. Epochal dropped off the public radar in January 2025, just after an esteemed group of Belgian brewers from Brasserie Cantillon, Brasserie de la Mule, Brasserie de la Senne and Gueuzerie Tilquin had visited to admire the new installation. 

Epochal Barrel Fermented Ales had folded, despite months of effort from founder Gareth Young to find a brewery to partner to regenerate his brand. The union, like all the equipment and stock in the brewery’s former unit on Payne Street in Glasgow reverted to the ownership of the landlord, Cairn Building Solutions. 

Although he no longer has any skin in the game, Gareth had attempted to facilitate Cairn’s efforts to find a buyer for the heritage equipment, keen that it should find a forever home in a UK brewery that will make best use of it. 

It was touch and go, with the founder of Cairn Building Solutions announcing that as no buyer had been found, the kit would go to scrap. However, thanks to the publicity surrounding this statement over the Christmas of 2025, a buyer was finally found. Serious interest came from an American brewery, but since their logistics were more complex, Cairn decided to accept an offer from the newly formed Springbanks Brewery in Wolverhampton. 

The Burton Bridge Brewery may have plans to build their own set, but there is another homemade union out there, little known but already in operation. It was made by Richard Baggeley, a homebrewer in Stone. 

He has converted a metal shed in his garden into the Wheatlow Brewery. Despite not being a keen draught Bass drinker, the preference his Staffordshire neighbours have for the beer set him on a journey to brew an authentic-tasting version. 

“​I ​wanted ​to ​get ​to ​the ​bottom ​of ​Bass because ​I ​never ​got ​anywhere ​near ​it. It ​was ​around ​the ​same ​time ​that ​Thornbridge got ​their ​union ​set ​up. They ​had ​six ​barrels ​on ​their ​union ​and six ​pins (4.5 gallon metal casks) is ​exactly ​my ​brew ​length. ​Something ​just ​clicked ​in ​my ​head ​and ​I ​thought I had to build one.” 

There are still a handful of unions or union-style sets outside of these islands that should also be noted. 

 Firestone Walker in California runs a modified union that resembles a solera system – it is barrel fermenting but with no trough. Their spokesperson said that they use their oak “specifically for our ​Brewmaster Collective beers and Barrelworks brand. We have a full Barrel Room set aside at the Paso Robles Brewery where we hold many of those beers.” 

 Coopers in Australia had a union-style piece of kit in their museum, beer writer Roger Protz noted on a visit in 2011. He described it as resembling “a cross between a union and a Yorkshire square. Don't forget the founder, Thomas Cooper, came from Yorkshire.” The system allowed for “double drop” brewing, where beer flows under gravity after the initial fermentation into a new vessel ready for the secondary fermentation. It is the same system used by Brakspear in Oxfordshire for their bitter, Gravity. 

Australia has form when it comes to union brewing. The biggest brewery in the country, Tooth & Co of Sydney, were described in the Brewer’s Journal as having a “union room not excelled by even anything in Burton.” Archive photographs of the pristine room exist from 1890. Tooth & Co had by then long since built, and ultimately sold, a brewery of their own in Burton upon Trent, the Crescent Brewery.