Burton Unions: Difference between revisions
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File:DSCF0029.JPG|Head Brewer Paul Bayley takes a sample | File:DSCF0029.JPG|Head Brewer Paul Bayley takes a sample | ||
File:DSCF0068.JPG|The trough slopes gently towards a transverse ‘feeder’ and from there collapsed fob is fed back into each cask. During cleansing, the yeast settles out in the top trough and the beer weirs into the feeder though valved connecting pipes. | File:DSCF0068.JPG|The trough slopes gently towards a transverse ‘feeder’ and from there collapsed fob is fed back into each cask. During cleansing, the yeast settles out in the top trough and the beer weirs into the feeder though valved connecting pipes. | ||
DSCF0069 The hole on the top right feeds the collapsed fob back into the feeder trough. The bottom left empties the trough at the end of fermentation and the larger hole in the base is used to remove the yeast crop. | |||
DSCF0069a The connections from the trough to the feeder on the right | |||
DSCF0069b The view of the connections to the feeder from below | |||
DSCF0069c The trough (below left) and feeder trough | |||
DSCF0069d Note the safety features of the Marstons sets. | |||
DSCF0070 The circulation of fob is driven by a 1oC temperature differential by applying cooling to panels in the top trough. This set under repair shows the cooling surface on the bottom of the trough | |||
DSCF0071 There are water cooled coils in each cask to lower the temperature before racking. Head Brewer Paul Bayley demonstrates. | |||
DSCF0072 When racking gravity is reached there is a crop of yeast in the trough and the cask has a yeast count in the order of one million cells. Remaining beer in the top trough is run to an empty cask in the set and the yeast is manually removed to a waiting trolley before transfer to cold storage. | |||
DSCF0072a A bottom trough runs the length of the set under each row of casks to empty them | |||
DSCF0074 The beer is racked from the casks by opening the taps below each cask. The tap is fitted with a plastic bag secured with a rubber band and the beer flows into a bottom trough with a minimum of fobbing. The trough empties by gravity and is fed to the racking vessels. Some 3 litres of ‘grounds’ held back in the cask by the length of the tap are run to waste before cleaning. | |||
DSCF0074a How Bass managed yeast counts and losses. This shows a bottom tap and the cask bottom boss. The left hand has been laboriously manually wound out '16 threads' as there is likely to be only a small volume of yeast in the belly of the cask. Latterly yeast counts were taken from the cask before racking. The right hand example shows the tap fully in to accommodate the full 3L which Marstons leave behind as a loss. | |||
File:DSCF0075.JPG|There is still a full time cooper on site with enough seasoned oak to last for a while | File:DSCF0075.JPG|There is still a full time cooper on site with enough seasoned oak to last for a while | ||
File:DSCF0076.JPG|The stock of timber in the brewery yard | File:DSCF0076.JPG|The stock of timber in the brewery yard |
Revision as of 18:11, 9 June 2016
Introduction
The Burton Union method of fermentation is essentially a ‘cleansing’ system. It is a means of removing yeast from beer as the fermentation finishes as well as collecting it for use in subsequent brews. It particularly suits the rather powdery strains traditional in Burton on Trent as the sedimentation distance is a matter of inches and not metres. Only Pedigree and Owd Rodger strong ale go through the union sets at Burton. About 40% of the Pedigree destined for cask sale is fermented to completion in squares and is blended with union beer before packaging.
A set comprises banks of 7hL unlined wooden casks, a unit of 26 casks (13 in two rows) would total a 100 barrel batch. There is a tap in the belly of the cask and opposite, a hole which takes a swans neck. This tube directs the fermentation froth from the cask into a trough which runs the length of the set at high level between the casks.
Detail of a cask head. The feeder arm is at the top to fill the casks and allow collapsed fob to return, on the right is the sample tap - only one per side of 13 casks. The flexible tubes run cooling water to the cask attemperators. The iron cross supports the cask on the frame. The cask is clamped into position but released for cleaning by attaching a crank to the trunnion stub.