The Brewing Process
The Ingredients
Malt:
Malt is barley specially treated for the brewing of beer. Selected varieties of barley are harvested, cleaned and graded. Germination is then allowed to take place at a required extend and then arrested by drying over a furnace. The rootlets produced on the corn during germination are removed by special techniques. The purpose of using malting barley is to modify the properties of its starch and its other natural components and render it suitable for the production of fine quality beer. KEO uses imported malt of the finest grade. From the malt store, malt is transported to the Brew-house where it is milled using a wet-milling process.
Hops:
The hop is a climbing plant cultivated for the purpose of being used in the brewing industry. The bitter resins and essential oils, which give beer its characteristic flavour and bitter taste, are secreted at the base of the female flowers. The quality of hops is of great importance to the beer and KEO uses a special blend of superior varieties.
The brewing process
The brewing process
Mashing:
From the mill, malt is mixed with specially demineralised water and pumped to the Lanter Tun where it undergoes a predetermined temperature treatment. By this treatment, starch and proteins, which are the major components of malt, are broken down and converted to fermentable sugars and simpler proteins respectively, during a series of reactions. These substances, together with other minor-components of malt, are dissolved in the water and give rise to liquor called “wort” which is of high nutrient value. The resulting wort is filtered through the bed of husks, which allows it to settle down, and passes through the perforated bottom of the mash-tun to the wort kettle.
Boiling:
The clear wort in the kettle is boiled in stages with hops in order to extract the essential oils and bitter resins of hops, which give the beer its characteristic flavour and bitter taste. The mashing and boiling processes are completed in eight hours during which 400 hl of wort are produced.
Trub separation and cooling:
From the kettle, the boiled wort is pumped at very high velocity tangentially to the next tank called “Whirlpool”. This action creates a centrifugal effect by which all protein; trub and spent hops are collected in the centre of the whirlpool, in the form of a compact “cake”. The clear wort is collected from the edge of the Whirlpool and pumped through a chiller to the fermenting tanks.
Fermentation:
This is the process by which about 80% of the fermentable sugars of wort are converted to alcohol and carbon dioxide by the natural action of yeast added to the wort. Many other substances, which contribute to the flavour of the beer, are also produced in small quantities. Fermentation takes about a week and is carried out under strict temperature control in cylindoconical tanks. The carbon dioxide, produced during the fermentation process, is collected, filtered, compressed and filled into cylinders.
Lagering (Maturation):
After fermentation is competed, the “young” beer is transferred to the lager cellars where it spends about six weeks in closed storage tanks at temperatures below zero. The process is that of slow fermentation which ferments the rest of the sugars, saturates beer with carbon dioxide and precipitates colloidal turbidity.
Filtration:
From the lager cellars, the beer passes through polishing filters where all precipitates and yeast are completely eliminated, and subsequently through sterilising filters which keep back all microorganisms, thereby avoiding the need for pasteurisation which would affect the quality of beer.
Packaging:
The Packaging Department has been completely renovated by investing about £5 million between 1992 and 1994. A new bottling line at 36,000 bottles per hour, with computerised flow control was put into operation in 1992. A fully automatic kegging line, producing 2240 kegs per hour was operated in 1993. In 1994 a new canning line, producing cans in all types of modern multi-packs was put into operation.
