Milling - The malt is first milled into coarse flour, keeping the barley husk material as intact as possible.
Mashing - This involves mixing the milled grist (malt, flaked barley and roast barley) with hot water to change the starches in the malt into fermentable natural sugars, which will be separated in the next process.
Extraction - The porridge-like mash is transferred to a kieve which operates like a sieve, and the sugary liquid, is then filtered off to a third vessel - the Kettle. The spent grains which are left behind are removed automatically and sold for cattle feed.
Boiling - Once in the Kettle, the wort is boiled with hops for approximately 90 minutes. The hops holds the bitterness and aroma which is a characteristic of Guinness.
Cooling - After boiling and settling in the Kettle, the wort is pumped to the Fermentation and Beer Processing Plant (FBP).
Each brew produces the equivalent of 250,000 pints of beer. 4,000,000 pints made daily making the brewhouse the main user of energy from the power plant, using 40% of the stations capacity this is equivalent to the amount of light and heat it required for 4,000 homes.