Fermentation:

Yeast is a living organism, and like all living organisms, needs food to survive. Fermentation is the process whereby yeast "eats" the fermentable sugars in the wort creating, among other things, the bi-products alcohol and carbon dioxide.

1. Place the primary fermenter in a dark, quiet place to ferment at approximately 68º-70º F for the next 14 days.

   Fermentation needs to occur at fairly specific temperatures. Although most yeasts can ferment successfully within in a fairly wide range of temperatures, top-fermenting ale yeasts prefer primary fermentation between 65º-75º F, while bottom-fermenting lager yeasts prefer primary fermentation temperatures in 40º-50º F range. (In case you didn't know, you're making an ale here.) Temperatures at or beyond the high end of the range will result in a faster fermentation, but slight off-flavors may occur that could be inappropriate to the style of beer you are brewing. Although near-freezing temperatures are often recommended for lagering beer, fermenting ales at cooler temperatures will slow fermentation down or even stop it altogether. Furthermore, wide or rapid fluctuations in temperature may cause off-flavors in the beer. In short, make sure the temperature of wherever you ferment is appropriate for the yeast strain being used and beer style being brewed and make sure that the temperature remains steady all day.

   Fermentation should occur within the first 48 hours after pitching the yeast. You will notice your airlock starting to bubble slowly at first then with much more regularity as the yeast hit its stride. Fermentation peaks violently before slowing down. Your average ale should ferment completely within 10-14 days.

2. Once fermentation is complete, take a final gravity reading with the hydrometer. The final gravity of this beer should be approximately 1.010.

   The beer is still fermenting if bubbles are still rising through the airlock on a regular basis. Beer that is still fermenting must not be bottled unless you want exploding glass bottles. For simple ales, such as this one, give your beer at least two weeks to be sure fermentation is complete.

   However, checking the specific gravity of your beer is the best way to determine whether or not the yeast has done its job. Whereas original gravity is the specific gravity of wort before fermentation begins, final gravity is the specific gravity of beer after fermentation is complete. Many homebrew recipes will provide you with a target original gravity and a target final gravity. These are important parameters if you really want to get the recipe exactly right or clone a commercial beer. Furthermore, knowing the original gravity and final gravity will tell you how much alcohol is in your beer. For example, if your original gravity is 1.055 and your final gravity is 1.015, you'll have an alcohol content of approximately 5.1% A.B.V. For now, just check out the measurements and conversions page for a chart explaining how to figure out how much alcohol is in your beer.