The Alpha Acid Units is a measurement of hops, calculated by multiplying the ounces of hops by the alpha acit percentage. This method of measurement is usually inaccurate; for accuracy of hops and hop bitterness, IBUs are commonly used.
In most cases today, brewers use a hydrometer to determine the alcohol content in their beer. It calculates the density of a liquid relative to water. Since malted sugars produced the alcohol in beer, the more sugar added into the brewing process, the denser the beer will be, therefore giving a higher alcohol content. Before fermentation, the brewer takes a hydrometer reading of the orignal gravity. The final gravity is taken after the fermentation process, once all the CO2 and alcohol has been produced. These measurements are taken at 60°F, simply because the hydrometer was designed to compare with water at 60°F. Now, to get the ABV, you simply take the original gravity, subtract the final gravity, and mulitply by the magic number 131. Voila, there is your Alcohol by Volume!
ABV is calculated by: (starting SG- final SG) * 131
The alcohol in, well, alcoholic drinks is ethanol. Ethyl alcohol is produced during fermentation by the yeast consuming malt sugars. It is the intoxicatingly enticing ingredient of beer, and some say the most important.
A major cereal grains, and when malted, the primary ingredient in beer.
This bottom fermentating yeast prefers the lower temperatures of the brewing process. Most lager beers are derived from bottom fermentating yeast that settles at the bottom of the tank.
A cask is essentially a beer container. This container, usually a metal or wooden barrel, often is used to continue fermentation even after the brewing process. Casks differ from kegs in that kegs usually are upright-standing, and casks lay on their sides. Beer in kegs can be filtered and pasteurized, and beer in casks usually isn’t. Casks come in so many sizes and shapes: pins, barrels, hogsheads, butts, tuns; each succeeding type of cask holds a larger volume of beer.
Draft beer, or draught, is a beer normally served from a cask or keg. Inside the keg is a beer engine. Draught means “to pull”, and, you guessed it, the bartender has to pull the hand pump to get the beer engine to pour a perfect draught.
Esters are the chemical compounds that result in estery, or the fruity or spicy aroma produced through fermentation.
Fermentation is where yeast, mother nature’s actor, is added to the brew to absorb the malt sugars and turn them into alcohol and carbon dioxide. Cooler, shorter fermentation periods produce ales, while warmer, longer fermentation periods give us lagers.
A climbing vine of the Cannabacinae family. The dried ripe cones of the female flowers of this plant, used in brewing, give beer its flavor, aroma, and bitterness.
The International Bitterness Units measures the hop bitterness in the final product. There is a wide range of IBUs in beer, anywhere from 5 to 100+ IBUs.
Germinated cereal grains that have been allowed to sprout, then dried or roasted. The drying process is known as "malting". The two step process includes getting the grains to germinate by soaking them in water, the germinating process is stopped by drying with hot air.
The Original Gravity measures the density of the malt liquid and the amount of sugars dissolved in the liquid. This measurement is always taken before the fermentation process, and often afterwards too, resulting in Final Gravity.
Six Row Barley
Six row barley is just that: barley with six rows of seeds on the stalk. Generally, Americans like six row barley because they like to brew using starches such as rice or corn. Because these starches lack enzymes, six row barley is used since it has a high enzyme content, which effectively converts the starches into sugars. The cons found in using six row barley is that it has a negative effect on the haze as well as the taste of the beer.
The Specific Gravity is the density or mass of a liquid, usually in comparison to water.
Top fermentating yeast prefer the warmer temperature of 55-75 degrees fahrenheit. When the yeast is fermenting it rises to the top. The charcteristics include a very thick rich yeast head. Ales, porters, stouts, and wheat beers are categorized as top fermenting yeast beers.
Two Row Barley
Two row barley, of course, has two rows of barley seed. Two row barley has a lower enzyme content and more starch than six row barley. Two row barley is also high in protein. Brewers are usually concerned with two row barley because it determines the amount of extract produced, which in turn affects the amount of beer that is able to be produced.
A rather large class of microscopic fungi that include the saccharomyces cerevisiae and saccharomyces carlsbergensis strain that are used in brewing. Yeast also processes sugars to create ethanol (alcohol) and carbon dioxide.
Unfermented beer, when subjected to the mashing process during the brewing of beer, has the sugar-laden liquid extracted from it. The sugar is then fermented, with the help of yeast, to produce alcohol.