1. Brewing
At the brewery the malt is cleaned, weighed and crushed to produce "grist". The grist is mixed with hot water in a "mash tun" (tank) and allowed to stand at a temperature which lets the starch from the malt convert into fermentable sugars. The mash is then transferred to a "lauter tun" where the liquid is separated from the grain residue. This sweet liquid is called "wort", (pronounced "wert".)
The wort is transferred to another tank called the "kettle" where liquid sugars are added and the mixture is boiled. During boiling, the protein material in the wort joins together to form "trub". The trub is removed by transferring the wort to a whirlpool.
2. Fermentation
After the trub is removed, the wort is cooled, and then transferred to a fermenter - a large closed vessel.Yeast is then added which converts the sugars into alcohol and carbon dioxide gas. During fermentation the yeast cells multiply many times. The carbon dioxide gas which is released is collected for use later. Fermentation continues until only non-fermentable sugars remain, when the fermenter is chilled to four degrees centigrade to stop fermentation. Yeast settles to the bottom of the vessel and from here it is removed for re-use, or sold and used to produce food products such as Vegemite.
3. Storage
Once the yeast is removed the beer is passed from fermentation to storage vessels. During transfer the beer is cooled to minus one degree centigrade. Hop extract, which gives beer its characteristic bitter flavour, is added at this stage, which permits greater flavour control and enables the brewer to maintain a better taste consistency. The beer stays in storage at this temperature, and any material which might impair the appearance, flavour and shelf-life of the beer settles out.
4. Filtration
Following a set time in storage, carbon dioxide gas collected during fermentation is added to give beer its characteristic head and sparkling taste. The beer is then passed through a filtration system to remove surplus yeast and protein.
5. Pasteurisation
This is a process of heating and rapid cooling which prolongs shelf-life and destroys any bacteria or other organisms in the beer. Canned and bottled beers are pasteurised in their containers, while draught beer is pasteurised by means of a special heat exchanger called a flash pasteuriser.
6. Packaging
The filtered and sparkling beer is packaged into bottles, cans and stainless steel casks, or kegs, ready for distribution around Australia or for export around the world.