Head brewer Jack Palmer explains what happens at the brewery in Bury St Edmunds, Suffolk, from receiving grain through beer manufacture and then when it is ready to be packaged.
The first aspect is milling where the entire grains from the maltings are crushed to get to the starch within that, which will be turned into sugar.
Next up is the mash tun process where the crushed grain is mixed with hot water at 60°C to 65°C. This allows the enzymes from the malt and water to turn to sugar, which will be fermented and turn to alcohol.
This liquid is now called the wort (pronounced ‘wert’) and goes into the copper vessel.
The stage in the copper is where the wort is boiled to 100°C to sterilise it and so hops can be added. This allows the alpha acids to convert into a bittering component.
Cooling system
After an hour, the liquid moves on to the whirlpool stage. Here, large blocks of protein material are separated and more hops may be added to create a ‘late hop’ aroma.
The wort is then cooled via a cooling system and is then moved on to a fermentation stage.
The cooling process will take ales down to between 16°C and 18°C while lagers will be reduced to 12°C.
Yeast is then added along with oxygen to help the yeast become active and begin growing before moving through to the fermenters.
In the big fermentation tanks, the yeast gets to work on breaking the sugars down and into alcohol. Also, ‘esters’ and ‘volatiles’ give the beer its aromas.
The process lasts between four and seven days before cooling takes place.
Differing final stages
The beer then goes to a conditioning stage after a centrifuge removes the majority of the yeast.
The beer sits in the conditioning tanks to develop further the remaining yeast before the filtration stage where haziness and haze-forming particles are removed.
The final stage before going to packaging - which could be cask, keg, canned or bottled – is the blending process.
Carbonation will be added if going to bottling, canned or keg formats but this stage will not take pace for cask products.
From fermentation, extra yeast is added to convert the residual sugar into beer for cask and this allows for a secondary fermentation in the barrel that adds carbonation.
