Asked in HomebrewingBeer and BrewingThe Difference Between
What is the difference between lager draught and ale?
December 05, 2008 10:10PM
While the term ale used to refer to beer brewed without yeast, today the difference between ale and lager is in the yeast as well as length and temperature of fermentation Yeasts come in a variety of styles, each developed for a certain style of alcoholic beverage. There are lager yeasts, champaign yeasts; yeasts used for pilsners, and several varieties of yeast for ale, lambic and barley wine styles. Each yeast variety has unique qualities that impact the final flavor and aroma of the beer.
The main difference between yeasts used for lagers and ales is that ale yeast is a top-fermenting yeast which means the yeast floats to the top and hangs around up there during most of the fermentation process. Lager yeast is a bottom-fermenting yeast which means it hangs around the bottom of the fermenter. During both types of fermentation the active yeast does permeate the brew and eventually settles out on the bottom of the fermenter when it is done.
The other main difference in producing a lager or ale is in the temperature during fermentation. Most ales are fermented at a controlled temperature around 70 degrees Fahrenheit. Lagers are generally fermented about 15 degrees lower, around 55 degrees.
The yeast and the fermentation temperatures play an important
roll in the flavor of the beer. Ale and lagers share the benefit of
a rich variety of flavors and aromas due to the yeast used, but
ales tend to be more robust and fuller flavored than lagers because
of the warmer fermentation. Colder fermentation tends to rob the
beer of flavors that may be imparted during this process because
the cold temperature subdues activity. This is also why lagers tend
to take longer to completely ferment, typically a week or two
longer than common ales.