Water
The most important ingredient of the beer making process. Specific water supplies, called liquor by brewers, are coverted for their unique purity and mineral make-up. An example of covert liquor is the bore liquor from the English town of Burton, home to many brewing house. Here the liquor has naturally high levels of calcium sulphate which increases malt extraction during the mashing process and results in clear, bright bitters.
Malt
The heart and soul of a brew, Malt is the result of toasting partially germinated grains in a kiln. Although barley is the most commonly used grain; wheat, oats and rye may also be used. Malt is responsible for the alcohol (produced from the sugars), much of the flavour and most of the colour of a beer. Variation of the toasting process results in different types of malts which help produce the varied number of beer types available.
Hops
First added to beer as a preservative to prevent it from going sour, hops have now become an important ingredient adding the characteristic bitter flavour and aroma of the brew. Hops are taken from the hop plant (Humulus lupulus), a tall, climbing plant which is a member of the hemp family. The active ingredient of hops, a complex oil found nowhere else in the plant kingdom, is found in the cones , which encase the female flowers of the plant.
Yeast
Water, malt and hops may account for the backbone, the soul and the uniqueness of beer, but it is the yeast that brings them altogether. By metabolising the sugars release from the malt, yeast produce the alcohol for the brew (and carbon dioxide which is a waste product unless utilized to produce the bubbles in bottle-fermented beers). The two types of yeast determine which class of beer the resultant brew falls into. Ales, including stouts, Trappists, wheat beers and porters, are brewed with top-fermenting yeast strains, while Lagers, including pilsners, ice beers and commercial bitters, are brewed with bottom-fermenting yeasts.