The Perfect Pint
The Brewing Process
Malt Intake
Malt is delivered to the brewery in 24 tonne loads from the maltings and loaded into a hopper and transferred to one of 8 x 38 tonne silos.
Milling
After passing over a destoner, a dust screen and a magnet, the malt is coarsely ground in the Mill and collected in the Grist Case over the Mash Tun.
Mashing
Brewing water from our own borehole is heated to 70°c and mixed with the ground malt as it goes into the Mash Tun. The mash, as it is called, is held in the mash tun for one hour during which time the starch in the malt is converted into sugar and solubilised.
After one hour the extract solution, which we call wort, is drawn off from the base of the Mash Tun and collected in the Copper. To ensure the maximum efficiency of extraction, the mash is washed through with the brewing liquor, a process called sparging.
Boiling
The wort from the Mash Tun is collected in the Copper which is essentially a large boiling vessel. In years past this vessel was made of Copper, but modern 'Coppers' are constructed of stainless steel because it is cheaper, easier to clean and harder wearing.
Before the start of the boil we add the hops and a small amount of special brewing sugar to the Copper. The boiling process sterilises the wort and helps the extraction of the bitterness and flavour from the hops. After boiling for an hour, the wort is pumped through a heat exchanger, which cools the wort to 18°c, into the Fermentation Vessel.
Fermentation
There are 96 Fermentation Vessels in 5 rooms around the Brewery. As the wort goes into the Fermentation Vessel yeast is added. The yeast converts the sugars in the wort to alcohol plus carbon dioxide. The actual fermentation usually takes between 3 and 5 days. After approximately 4 days the yeast from the fermentation is collected via a vacuum suction main into a chilled storage vessel. Each fermentation produces about three times the amount of yeast used to start with, the best yeast, as determined by microbiological examination, is used to pitch the following fermentations and the surplus yeast is sold to Marmite. Once the actual fermentation has finished, the beer is chilled to 12°c and held in the Fermentation Vessel for a further 48 hours to allow the natural flavour of the beer to develop.
Cask Beer
The majority of beer brewed here is traditional cask beer. Beer from 2 or 3 Fermentation Vessels are blended together in a holding tank before being filled into the cask. As the beer is filled into the cask, finings solution, which is produced from the swim-bladders of selected fish, is added. The finings are important in promoting the settlement of the yeast and clarification of the beer once the beer is in the pub cellar. We fill four sizes of casks, from 9 gallon firkins to 54 gallon hogsheads.
Keg Beer
Keg beer receives extra processing at the Brewery to produce beer with a longer shelf life. Beer from the Fermentation Vessel is held in a cold storage tank for a few days, and then filtered to remove all the protein and yeast. It is then pasteurised in-line before being aseptically filled into clean sterile containers.