Beer is made by mixing malted barley, water, hops and yeast together in an ordered manner. The first step is adding malted barley, which can either be malted by the brewer or substituted with a malted barley extract. Specialty grains then add color and body to the brew. The most commonly used grain is pale malt, though black, chocolate, crystal and roasted malts can be used to change the texture and taste of the beer. As the barley and grain, called wort, begin to boil in water, the grains are removed.
Hops contribute to the bitterness and aroma of the beer.
Before the days of refrigeration, hops were used to keep beer fresh. Hops are added to the wort at different times during the boil. Yeast inverts the sugars in the wort to alcohol and carbon dioxide and is added after the wort has cooled and is ready to be fermented. The two most popular types of beer, ales and lagers, are created by using different yeasts that affect the fermenting process. Ales, including pale ales, brown ales, stouts, porters and English and Scottish strong ales, are made with top-fermenting yeasts which are allowed to ferment for 10 or more days at temperatures above 60 degrees Fahrenheit.