Brewery
From Wikipedia, the free encyclopedia
A brewery can be a building or place that produces beer, or a business involved in the production of beer. Breweries can take up multiple city blocks, or be a collection of equipment in a homebrewer's kitchen. The diversity of size in breweries is matched by the diversity of processes, degrees of automation, and kinds of beer produced in breweries. Typically a brewery is divided into distinct sections, with each section reserved for one part of the brewing process.
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[edit] History
- See also: History of beer
The oldest brewery in the world still in operation is believed to be the Bavarian State-owned brewery Weihenstephan, found in the German city of the same name, which can trace its history back to 1040. Although the Zatec brewery in the Czech Republic claims it can prove paying beer tax in 1004.
[edit] The industrialization of the brewery
Beer, in some form, can be traced back almost 5000 years to Mesopotamian writings describing daily rations of beer and bread to workers. Before the rise of production breweries the production of beer took place at home and was the domain of women, as baking and brewing were seen as "women's work". Breweries, as production facilities reserved for making beer, did not emerge until monasteries and other Christian institutions started producing beer not only for their own consumption, but also to use as payment. This industrialization of brewing shifted the responsibility of making beer to men.
Early breweries were almost always built on multiple storeys, with equipment on higher floors utilized earlier in the production process, so that gravity could assist with the transfer of product from one stage to the next. This layout is often preserved in breweries today, but mechanical pumps allow more flexibility in brewery design.
Early breweries typically used large copper vats in the brewhouse, and fermentation and packaging took place in lined wooden containers. Such breweries were common until the Industrial Revolution, when better materials became available, and scientific advances led to a better understanding of the brewing process. Today, almost all breweries are made of stainless steel.
[edit] Major technological advances
A handful of major breakthroughs have led to the modern brewery and its ability to produce the same beer consistently.
The steam engine, vastly improved in 1765 by James Watt, brought automatic stirring mechanisms, and pumps into the brewery. It gave brewers the ability to more reliably mix liquids while heating, particularly the mash, to prevent scorching, and a quick way to transfer liquid from one container to another. Almost all breweries now use electric-powered stirring mechanisms and pumps. The steam engine also allowed the brewer to make greater quantities of beer, as human power was no longer a limiting factor in moving and stirring.
Carl von Linde, along with several other people, is credited with developing the refrigeration machine in 1871. Refrigeration allowed beer to be produced year-round, and always at the same temperature. Yeast is very sensitive to temperature, and if a beer was produced during summer, the yeast would impart unpleasant flavors onto the beer. Most brewers would produce enough beer during winter to last through the summer, and store it in underground cellars, or even caves, to protect it from summer's heat.
Most importantly, the discovery of microbes by Louis Pasteur was instrumental in the control of fermentation. The idea that yeast was a microorganism that worked on wort to produce beer lead to the isolation of a single yeast cell by Emil Christian Hansen. Pure yeast cultures allow brewers to pick out yeasts for their fermentation characteristics, including flavor profiles and fermentation ability. Some breweries in Belgium still rely on "spontaneous" fermentation for their beers (see lambic).
[edit] The modern brewery
Breweries today are made predominantly of stainless steel, although vessels often have a decorative copper cladding for a nostalgic look. Stainless steel has many favorable characteristics which make it a well-suited material for brewing equipment. It imparts no flavor in beer, it reacts with very few chemicals, which means almost any cleaning solution can be used on it (concentrated chlorine bleach being a notable exception) and it is very sturdy. Sturdiness is important, as most tanks in the brewery have positive pressure applied to them as a matter of course, and it is not unusual that a vacuum will be formed incidentally during cleaning.
Heating in the brewhouse is usually achieved through pressurized steam, although direct-fire systems are not unusual in small breweries. Similarly, cooling in other areas of the brewery is typically done by cooling jackets on tanks, which allow the brewer to precisely control the temperature on each tank individually, although whole-room cooling is also common.
Today modern brewing plants perform myriad analyses on their beers for quality control purposes. Shipments of ingredients are analyzed in order to correct for variations; Samples are pulled at almost every step and tested for oxygen content, unwanted microbial infections, and other beer-aging compounds; and a representative sample of the finished product is often stored for months for comparison when complaints are filed.
[edit] The Brewing Process
Work in the brewery is typically divided into 7 steps: Mashing, Lautering, Boiling, Fermenting, Conditioning, Filtering, and Filling.
[edit] Mashing
Mashing is the process of mixing milled grain (typically malted grain) with water, and heating this mixture up with rests at certain temperatures to allow enzymes in the malt to break down the starch in the grain into sugars, typically maltose.
[edit] Lautering
Lautering is the separation of the extracts won during mashing from the spent grain to create wort. It is achieved in either a Lauter tun, a wide vessel with a false bottom, or a mash filter, a plate-and-frame filter designed for this kind of separation. Lautering has two stages: first wort run-off, during which the extract is separated in an undiluted state from the spent grains, and sparging, in which extract which remains with the grains is rinsed off with hot water.
[edit] Boiling
Boiling the wort ensures its sterility, and thus prevents infections. During the boil, hops are added, which contribute their bitterness, aroma and flavor compounds to the beer, and, along with the heat of the boil, cause proteins in the wort to coagulate and the pH of the wort to fall. Finally, the vapors produced during the boil volatilize off flavors, including dimethyl sulfide precursors.
The boil must be conducted so that is it even and intense. The boil lasts between 60 and 120 minutes, depending on its intensity, the hop addition schedule, and volume of wort the brewer expects to evaporate.
[edit] Fermenting
Fermentation, as a step in the brewing process, starts as soon as yeast is added to the cooled wort. This is also the point at which the product is first called beer. It is during this stage that sugars won from the malt are metabolized into alcohol and carbon dioxide. Fermentation tanks come in all sorts of forms, from enormous tanks which can look like storage silos, to five gallon glass carboys in a homebrewer's closet.
Most breweries today use cylindroconical vessels, or CCVs, have a conical bottom and a cylindrical top. The cone's aperture is typically around 60°, an angle that will allow the yeast to flow towards the cones apex, but is not so steep as to take up too much vertical space. CCVs can handle both fermenting and conditioning in the same tank. At the end of fermentation, the yeast and other solids which have fallen to the cones apex can be simply flushed out a port at the apex.
Open fermentation vessels are also used, often for show in brewpubs, and in Europe in wheat beer fermentation. These vessels have no tops, which makes harvesting top fermenting yeasts very easy. The open tops of the vessels make the risk of infection greater, but with proper cleaning procedures and careful protocol about who enters fermentation chambers when, the risk can be well controlled.
Fermentation tanks are typically made of stainless steel. If they are simple cylindrical tanks with beveled ends, they are arranged vertically, as opposed to conditioning tanks which are usually laid out horizontally.
A very few breweries still use wooden vats for fermentation as wood is difficult to keep clean and infection-free and must be repitched more or less yearly.
After high kraeusen, a bung device (German: Spundapparat) is often put on the tanks to allow the CO2 produced by the yeast to naturally carbonate the beer. This bung device can be set to a given pressure to match the type of beer being produced. The more pressure the bung holds back, the more carbonated the beer becomes.
[edit] Conditioning
When the sugars in the fermenting beer have been almost completely digested, the fermentation slows down and the yeast starts to settle to the bottom of the tank. At this stage, the beer is cooled to around freezing, which encourages settling of the yeast, and causes proteins to coagulate and settle out with the yeast. Unpleasant flavors such as phenolic compounds become insoluble in the cold beer, and the beer's flavor becomes smoother. During this time pressure is maintained on the tanks to prevent the beer from going flat.
If the fermentation tanks have cooling jackets on them, as opposed to the whole fermentation cellar being cooled, conditioning can take place in the same tank as fermentation. Otherwise separate tanks (in a separate cellar) must be employed.
[edit] Filtering
Filtering the beer stabilizes the flavour, and gives beer its polished shine and brilliance. Not all beer is filtered. When tax determination is required by local laws, it is typically done at this stage in a calibrated tank.
Filters come in many types. Many use pre-made filtration media such as sheets or candles, while others use a fine powder made of, for example, diatomaceous earth, also called kieselguhr, which is introduced into the beer and recirculated past screens to form a filtration bed.
Filters range from rough filters that remove much of the yeast and any solids (e.g. hops, grain particles) left in the beer, to filters tight enough to strain color and body from the beer. Normally used filtration ratings are divided into rough, fine and sterile. Rough filtration leaves some cloudiness in the beer, but it is noticeably clearer than unfiltered beer. Fine filtration gives a glass of beer that you could read a newspaper through, with no noticeable cloudiness. Finally, as its name implies, sterile filtration is fine enough that almost all microorganisms in the beer are removed during the filtration process.
[edit] Packaging
Packaging is putting the beer into the containers in which it will leave the brewery. Typically this means in labelled bottles, kegs and casks, but it might include bulk tanks for high-volume customers.
[edit] Some brewery descriptions
Breweries range widely in the volume and variety of beer produced, ranging from small breweries that produce a few dozen barrels a year, to massive multinational conglomerates, such as InBev, that produce hundreds of millions of barrels annually. Some commonly used descriptions of breweries are:
- Microbrewery – A late 20th century name for a small brewery. The term started to be replaced with craft brewer at the start of the 21st century.
- Brewpub – A brewery whose beer is brewed primarily on the same site from which it is sold to the public, such as a pub or restaurant. If the amount of beer that a brewpub distributes off-site beer exceeds 75%, it may also be described as a craft or microbrewery.
- Contract brewing company or contract brewery – A business that hires another brewery to produce its beer. The contract brewing company generally handles all of the beers marketing, sales, and distribution, while leaving the brewing and packaging to the producer-brewery (which, confusingly, is also sometimes referred to as a contract brewer).
- Regional brewery – An established term for a brewery that supplies beer in a fixed geographical location. With modern distribution methods this term is falling out of use.
- Craft brewer – A term that is replacing microbrewery. A craft brewery is a brewery which does not use adjuncts and/or is considered to make craft beer.
- Macrobrewery or Megabrewery – Negative terms for a large brewery.
- A brewmaster is a person who is in charge of the production of beer. The major breweries employ engineers with a Chemistry/Biotechnology background. The title of Brewmaster is given to a person after 2½ years of extra study in the art of brewing thus earning a degree equivalent to a Ph.D.
[edit] Craft Brewing
Before Prohibition in the United States, breweries were local institutions, with a few exceptions. The costs involved in moving large quantities of beer while maintaining its quality necessitated that beer be made near where it was to be consumed. Prohibition, as could be expected, closed most of the breweries in the United States, and the few that were able to remain open by producing near beer, malt extract, yeast, and other beer-related products, were in an advantageous position to produce and sell beer after Prohibition was lifted. During Prohibition, the advancements in refrigeration and motorvehicles made large regional and national breweries possible. These remaining breweries quickly became large enough to be household names all over the nation, and concentrated mostly on the style with the broadest appeal: American light lagers. Local breweries, with their niche beers, were lost in America.
In 1978, Jimmy Carter signed into law a bill explicitly allowing people to brew beer for private consumption. As the homebrewing movement grew, homebrewers looked to re-create beers they had enjoyed in places with a more varied beer assortment. The rise of imported beers and homebrewing brought a demand for more beer styles, and locally brewed beer. Answering this need, smaller breweries started popping up across America, and a whole industry grew around the microbrewing industry. Many of these startup microbreweries, such as St. Paul's Summit Brewing Company, have since grown into major regional breweries in their own right.
Portland, Oregon has earned the name "Beervana", with more breweries than any other city in the world. With a mind-numbing 33 breweries just within the city limits. The McMenamin brothers alone have over thirty brewpubs, distilleries and wineries scattered throughout the metropolitan area, many in renovated theaters and other old buildings otherwise destined for demolition. Other notable Portland brewers include Widmer Brothers, Bridgeport Brewing Company and the MacTarnahan's Brewing Company. In 1999, "beerhunter" and author Michael Jackson called Portland a candidate for the beer capital of the world because the city boasted more breweries than Cologne, Germany.
[edit] See also
[edit] External links
[edit] References
- ISBN 3-921690-39-0: Technology Brewing and Malting, Wolfgang Kunze, 2nd revised edtion, VLB Berlin. Available at their website
- http://www.beertown.org/craftbrewing/statistics.html: Craft Brewery definitions at the bottom of the page
