In this traditional method for making ales, the yeast strain Saccharomyces cerevisiae operates at warmer temperatures, typically between 15 and 24 degrees Celsius. The vigorous production of carbon dioxide carries the flocculating yeast cells to the surface, forming a thick, foamy head known as kräusen. This warmer process generally produces more esters and phenols, giving ales their complex, fruity or spicy flavor profiles.
Heard on the job
We need to monitor the temperature closely on this top fermentation so the esters don't get out of control.
Do not mix it up with
- Bottom fermentation: Top fermentation uses ale yeast at warmer temperatures, while bottom fermentation uses lager yeast at cooler temperatures.