This is a rare surviving example of a system of fermentation favoured by the majority Burton’s brewers from the mid-nineteenth century onwards for the production of the ales for which Burton became famous.
This “double” Burton Union Set boasts 52 casks, each with a capacity of 150 gallons, giving the set a nominal total volume of 200 brewer’s barrels, or 7,200 Imperial gallons. At the end of the nineteenth century there were more than 100 such double Sets operating in Burton.
The Union system was particularly effective because during fermentation excess yeast was expelled naturally via the “Swan Necks” – the curled pipes inserted into the tops of the casks – into the “Top Trough”, where it stayed, chilled, until transferred for re-use in the next brew. The beer remained in the Union casks until run down into the wooden “Bottom Trough” and thence into large vats, from which it was racked (filled) into oak barrels for despatch to depots and onwards to customers.