BEER3110 – Brewing Process: Introduction – HMRC Internal Manual
Beer is an alcoholic beverage whose main ingredients 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 grains and sugar.
The brewing process can vary depending on the type and scale of equipment used, but the operation generally follows the sequence:
- water treatment – to achieve the required hardness levels suitable for brewing;
- milling – grinding malted barley to produce grain;
- mash – soaking grain (and other cereals) in hot liquor (water) in a mash container (also called a mash vat);
- boiling – wort drained and put in copper and boiled with hops and sometimes sugar;
- fermentation – wort separated from hops, cooled, collected in fermentation tanks and yeast added;
- cleaning/filtration – after fermentation the yeast can be removed;
- conditioning – a period of maturation before packaging, which normally lasts from a few days to six weeks or more (in exceptional circumstances); and
- packaging – filling kegs, kegs, cans, bottles and other containers with beer.
The nature and extent of the above operations vary according to the type of beer produced. The fermentation of lager beers generally takes place over a longer period than that of other beers. Beer that is to be keg-conditioned is not normally completely freed of yeast before racking into kegs, while beer intended for keg or canning is usually filtered and pasteurized (sterilized) before packaging.