Brewing Process: Introduction
Beer is an alcoholic beverage, the main ingredients of which are malted barley, hops and water to which yeast is added to produce alcohol by fermentation. Other ingredients may be used in addition to these, including other cereals and sugar.
The brewing process may vary in the type and scale of equipment used but the operation typically follows the sequence:
- water treatment - to achieve the required levels of hardness suitable for brewing;
- milling - grinding of malted barley to produce grist;
- mashing - steeping the grist (and other cereals) in hot liquor (water) in a mash vessel (also known as a mash tun);
- boiling - wort drained and put into the copper and boiled with hops and sometimes sugar;
- fermentation - wort separated from hops, cooled, collected into fermenting vessels and yeast added;
- cleansing/filtration - after fermentation yeast may be removed;
- conditioning - a maturation period prior to packaging, normally lasting from a few days up to six weeks or more (in exceptional circumstances); and
- packaging - filling casks, kegs, cans, bottles and other containers with beer.
The nature and extent of the above operations varies according to the type of beer being produced. Fermentation of lagers typically takes place over a longer period than other beers. Beer which is to be conditioned in the cask is not normally completely cleansed of yeast prior to racking into casks, whereas beer which is destined for kegging or canning is usually filtered and pasteurised (sterilised) before packaging.