How we acquired the Union Set and how it works

Watch how the Burton Union system was installed and brought back into use at Thornbridge

Beer flowing into the trough from the swan neck pipes on the Thornbridge Union set
The Thornbridge Union Set under construction

Thornbridge Brewery saves the Burton Union

In 2024, Thornbridge Brewery rescued and restored a section of the historic Burton union system — saving a 19th-century fermentation method from permanent extinction, and becoming the only brewery in the world still operating one.

When Carlsberg Marston's announced, at the start of 2024, that they were retiring their historic Burton union system, we were as sad as everyone else. So when we found out there was an outside chance Thornbridge were going to be able to obtain a small section of a Burton union, thanks to our old friend Garrett Oliver and the CMBC team, we grabbed the opportunity with both hands.  It’s now May and to actually have them on site, ready to use, is a dream come true for myself and the rest of the brewing team. Clearly, this is a fantastic opportunity for Thornbridge to take a piece of brewing history and be able to continue producing beers on one of these sets, rather than the entire process being consigned to the history books and drinkers never being able to sample beer produced in this unique way.

       The union installed at riverside brewery        The barrels of the union system at riverside brewery

It took numerous visits from the brewing team in the early part of the year to determine if the unions were actually going to be workable for us. Firstly, we needed to make sure we had the space for the union set, which we created by moving the bottling line from the smaller brewhouse area, at the back of the taproom. Crucially, we had to get our heads around how the process worked, so we knew we could not just fill the barrels and ferment beer in the union set, but also be able to clean it all properly.  As one of the reasons the system is being decommissioned in Burton is just how labour-intense the process is, we thankfully saw that, although it will be hard work looking after it, as it is just part of the original set, it looks doable!  I must say that the team at CMBC, their engineers and particularly Mark Newton, their Cooper, have been incredibly helpful and are as enthusiastic as we are. We fully intend to help protect the historic legacy of the union system and also see how it can help us innovate and develop our beers in the future.

By Rob Lovatt, Head Brewer/Production Director at Thornbridge Brewery (20+ years brewing experience)
    Beer being brewed within the Thornbridge Union Set

    Save The Union

    The Union System dates back to the 1800s and is a beautiful wood-barrel fermentation system that has been used continuously in the production of different beers over the decades. Thornbridge has stepped in to save one of the sets, not only for its historic importance, but also to utilise it in a modern way and continue to premiumise the cask beer range. Starting with a brew of our flagship beer, Jaipur, we will follow up by brewing other much-loved beers from our catalogue, new beers specifically for the Union kit and collaborations.

     

    Jaipur, (on the union) 5.9% IPA, 8 x 500ml bottles Beer - Case Bottle Thornbridge

    Jaipur from the Union

    On the 20th of May, we brewed a double Jaipur at the Riverside brewery, producing 10,000 litres of wort.   About 14 hours later, on the 21st of May, half of this Jaipur wort was transferred to the Union system and fermented there for about 4 days before being dropped out of the Union and pumped back into a separate racking tank.  A few days later, we racked this, our first ‘union’ beer, into casks in the usual way, with priming sugar and finings and cask-conditioned them in our cold store.

    On Friday we racked up a cask of the Union Jaipur in our taproom cellar, vented and tapped it and finally today we’ve got our first pour of on the bar, through a handpump, next to the normal version, to try them next to each other.  It’s not that easy to tell the difference between the two, but they are certainly different and both are great beers in their own right.

    Even as a Head Brewer with 20 years plus experience, I am still trying to find the words to articulate the difference.  I would describe the Union-fermented version as more rounded and softer and perhaps less bitter.  Let us know what you think!

    Rob Lovatt, Head Brewer/Production Director

    The Union pump clip on barrel number 11 of the Thornbridge Union Set

    Collaboration Brews

    Collaboration brews on the System will be an integral part of its future at Thornbridge; bringing together breweries with a keen sense of history who would like to help innovate with the system.

     

    "When I heard that the unions were slated to go silent, I immediately thought that Thornbridge would be the perfect inheritors of this beautiful piece of British brewing heritage. I'm thrilled to provide the 'assist' on this historic play." Garrett Oliver, Brewmaster, Brooklyn Brewery.

     

    “To have the chance to brew on a small part of The Union is incredible for us. We are so grateful to be given this opportunity and will make sure that great beers are brewed on the Thornbridge Union. It will give us a chance to collaborate, innovate and create premium cask beer whilst providing a new showcase for this important piece of brewing history.” Simon Webster, CEO and Co-Founder, Thornbridge Brewery.

    Brews from The Union

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    Articles on the Union

    The below videos were produced by Matthew Curtis one of the founders of Pellicle. Pellicle is an independent online magazine and podcast based in Manchester, England. Pellicle's primary aim is to capture the joy we so often find within our favourite drinks cultures.

    Listen to the Podcast : How Thornbridge Saved The Burton Union

    The Burton Union

    The Birth of the Thornbridge Union

    Masham Ale from The Union

    Learn more about Thornbridge’s traditional union set and how it shapes the character of our beers

    FAQ's on the Union

    What is a Burton Union set?

    A Burton union set is a traditional fermentation system developed in Burton-upon-Trent in the 19th century. It consists of a series of interconnected wooden casks and pipes that allow beer and yeast to circulate naturally during fermentation. As the beer ferments, excess yeast is expelled and separated, while the beer flows back into the casks, helping to create clean, balanced flavours and maintain healthy yeast

    Is Thornbridge the only brewery using a union set in the UK?

    Thornbridge Brewery operates the only working union set currently in use in the UK. and as far as Thornbridge's brewing team and CAMRA are aware, our set is the only working Burton union system in operation anywhere in the world

    Burton union sets were at risk of being lost entirely, so maintaining this rare and unique system reflects our commitment to traditional brewing alongside modern techniques.

    Can visitors see the union set at Thornbridge Brewery?

    Yes, visitors can see the union set as part of the Thornbridge Experience at the Brewery in Bakewell. The experience takes place next to the Union set and provides an opportunity to taste the beers and learn about brewing methods

    What beers are brewed using the union set at Thornbridge?

    Thornbridge uses the union set for selected beers where traditional fermentation enhances flavour and character. Availability can vary depending on brewing schedules and seasonal releases.

    Why were union sets phased out of modern brewing?

    Union sets were gradually phased out as breweries modernised and prioritised efficiency. They require significant space, time and manual input, whereas modern fermentation vessels are easier to manage and scale. As a result, most breweries moved away from union systems despite their traditional benefits.

    Why is it important to preserve traditional brewing methods?

    Traditional brewing methods are part of the history and identity of British beer. Keeping them in use helps preserve that heritage while offering something different to modern processes. It also ensures that skills and techniques are not lost over time.

    Why does Thornbridge continue to use a union set today?

    We continue to use a union set because of the character it brings to certain beers and its importance as part of brewing heritage. While it’s more labour-intensive than modern methods, it allows us to produce beers in a way that reflects traditional techniques alongside contemporary brewing

    Does beer taste different when brewed on a union set?

    Yes, it can. Union set fermentation helps create beers with a clean, balanced profile, while allowing subtle characteristics to develop during the process. The result is often a beer with clarity and depth that reflects the way it was fermented.