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Brewing Prcess Summary
Here you will find each step in the brewing process briefly summarised. Click on the 'more details' links to read further (Hold cursor over image caption).
Milling
The various different types of malt are passed through the mill where they are ground into grist. The grist is then carried by a conveyer up into the grist case ready for mashing the next day.
Mashing
The grist is mixed with hot water (liquor) to form a mash in the Mash Tun. The natural enzymes of the malt break down the malt starch into sugars which dissolve in the surrounding liquor to form sweet wort. This extract is run off from the Mash Tun into the boiling kettles.
Wort Boiling
The wort in the kettles is heated up to boiling point and boiled vigourously. Hops are added to give bitterness to the final beer.
Separation
During the boiling process, a large amount of protein and tannin is precipitated and this along with the spent hops has to be seperated from the bulk of the now bitter wort.
This is carried out in a whirlpool separator in which a vortex of wort is created, allowing the solids to settle out. Aroma hops are added at this stage.
Wort Cooling
The wort is cooled from around 90°C to around 18°C, before pumping into the Fermenting vessel. This is carried out in the wort heat exchanger or paraflow. The heat from the wort is transferred to cold mains liquor flowing through the paraflow, thus heating up the liquor to a temperature where it can be used for mashing. This process recovers some of the energy used in the boiling process.
Fermentation
This cooled wort is run into the Fermenting Vessel (FV), at a temperature of between 18 and 20°C, depending upon the time of year. Yeast is added at this point and fermentation begins. The yeast breaks down the sugars extracted from the malt in the Mash Tun, to form alcohol and CO2. The energy the yeast obtains during fermentaion, allows it to multiply itself some four, or more, times. The yeast tends to rise to the surface during fermentation so that by the time fermentation is finished, a thick head of yeast has formed on the surface.
Cooling water is run through a cooling panel within the FV, when the fermentation is finished, and the head of yeast is skimmed off. The yeast collected can be used for subsequent brews.
After a period of 7 days in FV the beer is ready to rack into cask, or be transferred to tanker and sent to our bottlers Frederic Robinson of Stockport.
Cask Racking
The casks and the racking plant are carefully sterilized. Auxiliary finings are added to the casks, and the beer is filled through the racking machine directly from the FV. The casks are sealed with a shive int the bung hole and stored at 10-15°C, for a minimum period of 5 days, to allow the secondary fermentation to be carried out by the small amount of yeast still in suspension.
Prior to being sent to the pub, the casks are re-opened and isinglass finings are added. Once the cask has been delivered into the pub cellar, it is vented to allow the excess CO2 to work off and the finnings to react with the yeast forming large clumps of sediment which settle rapidly to the bottom of the cask leaving the beer bright and clear.
Tanker/Bottling
The beer which leaves the brewery in tanker, directly from the fermentation vessels, is sent to Frederic Robinsons' Brewery in Stockport where it under goes a number of processes, before ending up in a shrink-wrapped tray of labelled bottles ready to be sent to a supermarket.
Cold Conditioning
The beer is pumped from the tanker through a chiller which brings the beer temperature down to 0°, before it goes into the cold conditioning tank. The beer is kept at this temperature for a minimum of 10 days during which time more of the protein and tannin, referred to the 'Wort Boiling' stage, precipitates out of the solution. This is an important part of the process, because the shelf-life of the final bottle of beer depends very much on the success of the cold conditioning process.
Filtration
After cold conditioning, the beer is passed through a filter that removes all the chill haze formed during this time, as well as any other particles of yeast, etc which may be present. The clear, bright and stable beer is then passed on into the Bright Beer Tank (BBT).
Bright Beer Tank
In the BBT, various physical parameters of the beer are checked and any adjustments are made prior to bottling.
Bottle Filling
The beer is pumped from the BBT to the filling machine where it is filled into bottles that have been rinsed with sterile water and examined electronically, for any sign of damage or foreign material. The filling process is obviously critical, in so far, that all the care to get the beer to the state of perfection in the BBT, could be lost if the filling was not carried out under carefully controlled conditions of temperature, pressure and sterillity.
As soon as the bottle is filled it is sealed with a crown cork and conveyed to the pasteurizer.
Pasteurization
On the way to the pasteurizer the bottles are electronically checked to ensure that each bottle has a crown and is filled to the correct height. In the pasteurizer itself the bottles are carried along a moving bed through water jets, which slowly raise the temperature to 60°C, hold it at that temperature for 20 minutes then slowly cool it down again. This effectively sterilizes everything in the bottle.
Packaging
After pasteurization the bottles are labelled, packed into trays, shrink wrapped, and palletized ready to be sent back to Broughton.
