Changes

Yeasts come in two three basic types - top fermenting ale yeast and bottom fermenting lager yeasts. Of the two, ale yeast are most commonly used for homebrewing because it can be fermented at room temperature.* '''Top Fermenting Yeast''' - Commonly called ''ale yeast'' formally known as ''Saccharomyces cerevisae'' are fermented at or just below room temperature (10-25 C). These yeasts rise during fermentation and form a foamy head at the top of the fermentation vessel. They also produce a strong estery flavor that is a key characteristic of ales. Stouts, Porters and all forms of Ale are made with top fermenting yeast.* '''Bottom Fermenting Yeast''' - Called ''lager yeast'' formally known as ''Saccharomyces uvarum'' is fermented at low temperatures in the range of 7-15 C. Lager yeast grows slowly and tends to settle at the bottom of the fermenter because of the cold temperature. Bocks, Pilsners, Marzens and popular American lagers are made with this type of yeast.* '''Bavarian Wheat Yeast''' - Used in Bavarian style wheat beers - known formally as ''Torulaspora delbruechii'' is a yeast that produces a distinct bannana or clove like flavor profile that is characteristic of the Bavarian Wheat Beer.