The mash is transferred to a ‘lauter tun’ to separate the sugar liquid, called ‘wort’, from the remaining solids. The clear wort flows to a metal brew kettle where it is boiled. The remaining grain solids (or spent grains) are sold as cattle feed.
As the wort is boiling in the kettle, carefully selected hops and other natural flavourings may be added to the kettle according to the brand recipe. The quantity, variety and even the time at which the hops are added all contribute to the different taste attributes of the beer.
During the boil, large proteins in the wort come together to form solid protein clumps. The wort is transferred to a ‘hot wort tank’ where the remaining solids from the hops and protein settle out and are removed. Once the wort is clear, the hot wort is cooled as it is transferred to the fermentation tank.
On the way, one of two different kinds of yeast is added. One type, a lager yeast, settles to the bottom of fermenter. The other, ale yeast, rises to the top of the liquid during fermentation.