A method of fermentation where the yeast is fermented at warmer temperatures, typically at temperatures of 68 and 72 degrees Fahrenheit (20 and 22 degrees Celsius). One of the benefits of the fermentation is that the flavors are generally considered more complex as are the aromas associated with the resulting beer. The resulting drink is usually ready to drink after 3 weeks but may be stored for longer.

This is in contrast to cold fermentation, where fermentation occurs, as the name implies, at colder temperatures. Less fruity flavors result from cold fermentation due to less esters being produced from this method. Additionally, beers produced via cold fermentation are usually stored for longer periods of times. However, the resulting flavor is usually considered more crisp.