The two most common species used in modern brewing are distinguished by their fermentation behavior and temperature preferences:
: Fermentation completes, and the yeast clumps together (flocculates) and settles to the bottom, allowing the beer to clarify. Essential Brewing Resources Brewing yeast and fermentation
Fermentation typically unfolds in a consistent biological progression: The two most common species used in modern
: The yeast population explodes, rapidly consuming sugars and producing the bulk of the beer’s alcohol and CO2. During this time, healthy yeast can "clean up"
: As sugar levels decline, yeast activity slows. During this time, healthy yeast can "clean up" undesirable byproducts like diacetyl, which can otherwise cause off-flavors.
Brewing yeast acts as the biological engine of the fermentation process, transforming the sugary liquid known as into beer. This single-celled fungus consumes malt-derived sugars—primarily maltose and glucose—and converts them into ethanol (alcohol) and carbon dioxide (CO2) through a process called alcoholic fermentation.
For those looking to dive deeper into yeast management and fermentation science, several definitive guides are available: