During runoff, the mash is sparged with 76 degrees Celsius water to extract as much sugar as possible. After approximately two and one half hours, the runoff to the kettle will be complete and boiling can begin. 1 hour Hops are the principle addition to wort during kettle boiling. Proper hopping of the wort is essential for good beer. At the beginning of a boil, hops are added for flavour and bitterness.
Hops also act as a natural preservative because of their acid content.
The wort is then cooled through a water-chilled heat exchanger. The wort is cooled to between 10 degrees Celsius and 17 degrees Celsius depending on the type of brew and yeast strain, and then transferred to a fermenter. Yeast and sterile air are added which starts a series of effects that convert the wort into beer. This is fermentation. During the fermentation, the fundamental effect produced by the yeast is the conversion of the fermentable sugars in the wort, developed during the mashing process, into ethyl alcohol, or ethanol, and carbon dioxide.