|Here we are - Roosters Omahu Road Hastings|
|Raw material - malted barley|
|Roasted to different toast levels|
|Hop flowers dried on the vine over the door|
|The wort is drained to the kettle and the mash dug out. Here's Darryl.|
|Here's the mash, off to the cows|
So the raw materials - water and malted grain - mix together and the enzymes in the grain convert the carbohydrates in the grain into simple sugars, and then these are leached out into the hot water.
The boiling sterilises the wort, denatures the proteins so they can settle out and also extracts the aromatic and bittering components from the hops that are added. The hops are added early on for maximum extraction, though some styles of beer require a second, late hop addition to increase the aromatics in the beer - India Pale Ales and Pilsener are examples of a late-hopped style.
|The wort is cooled as it is pumped into the fermenters, with yeast and oxygen|
Heat is recovered from the wort by the plate heat exchanger, and returned to the water tank for tomorrows brew. The wort is reduced from 100 deg C to 15.
Fermentation takes about a week, a little longer for the higher alcohol styles. Alcohol content is determined by the level of fermentable sugar in the wort, (like brix in grape juice) and can be increased by putting more malt into the mash tun at the beginning, or decreased by adding more water.
The ferment is quite vigorous, depending on the yeast and temperature.
|Filter cleans up the green beer that has finished ferment and settled for a month in conditioning tanks|
Diatomaceous Earth filter - also used for wine production. Clarifies the beer once it has sat for a month in the chiller tanks to settle and mature. This conditioning process is called Lagering but is not exclusive to lager styles.