Top fermenting yeast refers to a specific type of yeast used in the process of fermentation in brewing and baking. This type of yeast, also known as ale yeast or Saccharomyces cerevisiae, is called "top fermenting" because it tends to rise to the top during fermentation. Top fermenting yeast is characterized by its ability to ferment at higher temperatures, typically between 15°C and 24°C (59°F and 75°F), which is comparatively warmer than other types of yeast.
Unlike bottom fermenting yeast, which settles to the bottom of the fermentation vessel, top fermenting yeast shows a more vigorous fermentation activity, forming a thick layer or krausen on the surface. This leads to a higher production of esters and other flavor compounds, contributing to the distinct fruity and spicy flavors and aromas associated with ales. Top fermenting yeast is commonly used in the production of ales, including pale ales, stouts, and porters.
Furthermore, top fermenting yeast is versatile and widely used in the brewing industry due to its ability to ferment in a shorter period of time compared to other yeast strains. It is also known for its ability to tolerate higher alcohol concentrations, making it suitable for stronger beer styles such as barleywines and imperial stouts.
In summary, top fermenting yeast refers to a type of yeast that rises to the top during fermentation, ferments at higher temperatures, and is commonly used in the production of ales, providing distinct flavors, aromas, and a shorter fermentation time.
