The two most common species used in modern brewing are distinguished by their fermentation behavior and temperature preferences:
: Often called "top-fermenting" yeast because it rises to the surface during active fermentation. It thrives at warmer temperatures (typically 15–24°C / 60–75°F) and produces fruity esters and spicy phenols, which are characteristic of IPAs, stouts, and Belgian ales. Brewing yeast and fermentation
: Fermentation completes, and the yeast clumps together (flocculates) and settles to the bottom, allowing the beer to clarify. Essential Brewing Resources The two most common species used in modern