Tuesday, August 15, 2006

How Beer Is Made

MASHING: The first phase of brewing, in which the malted grains are crushed and soaked in warm water in order to create a malt extract. The mash is held at constant temperature long enough for enzymes to convert starches into fermentable sugars.

SPARGING: Water is filtered through the mash to dissolve the sugars. The darker, sugar-heavy liquid is called the wort.
Boiling: The wort is boiled along with any remaining ingredients (excluding yeast), to remove excess water and kill any microorganisms. The hops (whole, pelleted, or extract) are added at some stage during the boil.

FERMENTATION: The yeast is added (or "pitched") and the beer is left to ferment. After primary fermentation, the beer may be allowed a second fermentation, which allows further settling of yeast and other particulate matter ("trub") which may have been introduced earlier in the process. Some brewers may skip the secondary fermentation and simply filter off the yeast.

PACKAGING: At this point, the beer contains alcohol, but not much carbon dioxide. The brewer has a few options to increase carbon dioxide levels. The most common approach by large-scale brewers is force carbonation, via the direct addition of CO2 gas to the keg or bottle. Smaller-scale or more classically-minded brewers will add extra ("priming") sugar or a small amount of newly fermenting wort to the final vessel, resulting in a short refermentation known as "cask-" or "bottle conditioning".

After brewing, the beer is usually a finished product. At this point the beer is kegged, casked, bottled, or canned.