Once the "sweet wort" is transferred into the kettle it is brought to a rolling boil. While the boil is maintained the hops are added. There are three types of hops used during this process: bittering hops, aroma hops, and finishing hops. Each of these hops influences the beer's specific taste and fragrance. After the hops are added the wort is then whirl pooled, cooled through the heat exchanger, transferred into the fermenting tanks, and yeast is added.