Brewing
Brewing is the production of alcoholic beverages through fermentation. This is the method used in beer production, although the term can be used wine and other drinks such as Sake as well. The term is also sometimes used to refer to any chemical mixing process.Brewing has a very long history, and archeological evidence tells us that this technique was used in ancient Egypt. Descriptions of various beer recipies can be found in Sumerian writings, some of the oldest known writing of any sort.
The brewing industry is part of most western economies.
All beers are brewed using a process based on a simple formula. Key to the process is malted barley which has been allowed to germinate and is then dried in a kiln and sometimes roasted. Depending on the amount of roasting, the "malted barley" will take on dark color and strongly influence the color and flavour of the beer.
The malt is ground into a coarse powder, known as grist, which is mixed with heated water in a vat called a "mash tun" for a process known as "mashing". During this process, natural enzymes within the malt break down much of the starch into sugars which play a vital part in the fermentation process. Mashing usually takes 1 to 2 hours. The mash is held at a temperature of 149 to 154 ÃÂðF (65 ÃÂðC). The Mash Tun generally contains a slotted "false bottom" which acts as a strainer allowing for the separation of the liquid from the grain.
After mashing the resulting liquid is strained from the grains in a process known as lautering. At this point it is known as wort. The Wort is moved into a large tank known as a "copper" or kettle where it is boiled with hops and sometimes other ingredients such as herbs or sugars. The boiling process serves to terminate enzymatic processes, precipitate proteins, isomerize hop resins and sterilize the wort. Hops add flavour, aroma and bitterness to the beer. At the end of the boil, the hopped wort settles to clarify it in a vessel called a "whirl-pool" and the clarified wort is then cooled.
The wort is then moved into a "fermentation vessel" where yeast is added or "pitched" with it. The yeast converts the sugars from the malt into alcohol, carbon dioxide and other components through a process called ""Glycolysis"". After a week or so, the fresh (or "green") beer is run off into conditioning tanks. After conditioning for a week or longer, the beer is often filtered to remove yeast and particulates. The "bright beer" is then ready for serving or packaging.
Ale yeast was used exclusively until the mid-late 1700s. Ale yeasts fement at warmer temperatures of 65 to 75 ÃÂðF (18 to 24 ÃÂðC) and tend to collect on the surface of the fermenting beer. Because of this they are often referred to as Top Fermenting yeast. Ales are generally ready to drink within three weeks after the beginning of fermentation. Ales range in color from very pale to black opaque. England is best known for its variety of Ales.
Lager yeast brewing evolved in the mid 1800s in Germany. Lager yeast tends to collect at the bottom of the fermenter and is often referred to as Bottom Fermenting yeast. Unlike ale, lager is fermented and then stored for 30 days or longer close to the freezing point. During the storing or Lagering process, the beer mellows and flavors become smoother. Sulfur components developed during fermentation disipate. The popularity of lager was a major factor that led to the rapid introduction of refrigeration in the early 1900s.
Today lagers represent the vast majority of beers produced, the most famous being a light lager called Pilsner which originated in Pilsn Czech Republic. It is a common misconception that all Lagers are light in color but lagers range from very light to black opaque just like Ales.
Brewing Beer
Ale
Lager
See also