Malting

Brewing starts at the malting company where the maltster encourages the barley to germinate. To do this the barley is steeped in water and then allowed to swell a little. This brings about germination. The barley begins to produce enzymes that are used in the brewing process to breakdown the starch in the malt into sugar that the yeast can convert to alcohol.

Mashing

The malt is first milled to make grist. The grist is added to hot water to make a mash. In this mash the starch and sugars from the malt are extracted into the hot water. By carefully controlling the temperature the brewer also encourages the breakdown of starch into simple sugars that the yeast can metabolise. The sugary solution that results from mashing is called wort.

Lautering

To remove the malt husks, the wort is passed through a simple filtration vessel called a lauter tun. The sweet wort is transferred to the kettle for boiling and the husks and other insoluble material are retained in the lauter tun. What is left in the lauter tun is called spent grains and this is used as animal feed by a local farmer.

Boiling

The wort is boiled in the kettle and when it has come to the boil, hops are added. The boil is carried out for over an hour to sterilise the wort and also extract the flavour and bitter compounds from the hops. After boiling the hopped wort is chilled and sent to the fermentation room.

Primary fermentation

The hopped wort is placed into a fermentation vessel. Here the hopped wort is pitched with yeast and the fermentation begins. The temperature of the vessel is carefully controlled to ensure a consistent fermentation. In primary fermentation the majority of the sugar is turned into alcohol by the action of the yeast. After a week the beer is transferred to the maturation room.

Secondary fermentation

During secondary fermentation the yeast continues to ferment the remaining sugar to alcohol but at a much lower temperature. This is a maturation process and it is very important to let time take its course. As well as making alcohol the yeast also produces the gas, carbon dioxide. This dissolves in the beer and gives the beer its characteristic effervescence. The beer is now called green beer. After three to four weeks the beer is then ready for filtration, packaging and then consumption.