The Union IPA, Thornbridge

The Union IPA (7 per cent)

Thornbridge Brewery in Bakewell, Derbyshire, has made good use of its “union set” fermenter to launch an IPA in cask and bottle.

The union was donated by Marston’s in Burton-on-Trent when the last section of the system was taken out of action in January. The Burton brewery is part of the Carlsberg Marston’s Brewing Company (CMBC) and Marston’s has now sold its breweries to its Danish partner and has quit brewing after more than a century and a half.

The union system was developed in 1838 by a brewer from Warrington, Peter Walker, who had gone to Burton to make use of the famous mineral-rich water to produce the new vogue beer, pale ale.

The system consists of rows of giant oak casks linked by troughs and pipes or “held in union”. Beer production begins in traditional open square fermenters but once fermentation is underway liquid and yeast are transformed to the union casks.

Fermentation drives liquid and yeast out of the casks and up swan neck pipes and into troughs above. The troughs are held at a slight angle, allowing the liquid to run back via more pipes into the casks while the yeast is held back and used for further batches.

The end result was sparkling pale ale. The only problem with the unions was the cost of maintaining them. Resident coopers were needed to restore the oak casks and build new ones, while large amounts of water were required to clean the entire system.

One by one, the Burton brewers, including such giants as Allsopps and Bass, phased out their unions and used different methods to cleanse beer of yeast. But Marston’s remained faithful to them as it felt it gave its ales – Pedigree Bitter in particular – a unique flavour and character.

Thornbridge will use its union to make occasional batches of its main brands, including Jaipur IPA, and collaborative beers with other brewers from Britain and abroad. The Union IPA is the first beer to be made solely using the system.

It immediately proved popular in cask (6 per cent) and in August CAMRA’s Peterborough beer festival awarded it a gold medal in the Strong Ales category of its beer competition.

The packaged version is bottle conditioned and is stronger than the cask. It’s brewed with Maris Otter malting barley from Norfolk with Simpson’s Best Crystal Malt and a large amount of Invert Sugar No 2 for strength and flavour.

The finished beer has a pale bronze colour with apple and orange pith notes on the aroma balancing rich biscuit malt. Ripe fruit, toasted malt and a hint of spice dominate the palate while the finish is long and bittersweet with apples notes dominating but with continuing notes of biscuit malt and spice from the hops.

£3.50 from www.thornbridgebrewery.co.uk.