Brewing is the production of alcoholic beverages and alcohol fuel through fermentation. Although Fossil fuels have become the dominant Energy resource for the modern world Alcohol has been used as a fuel throughout history Fermentation in Food processing typically refers to the conversion of Sugar to Alcohol using Yeast under Anaerobic conditions This is the method used in beer production, although the term is also used to describe the fermentation process used to create wine, mead. Beer is the world's oldest and most widely consumed Alcoholic beverage and the third most popular drink overall after water and tea Wine is an Alcoholic beverage made from the fermentation of Grape juice Mead (ˈmiːd is a fermented Alcoholic beverage made of Honey, Water, and Yeast. It can also refer to the process of producing sake and soy sauce. Soy sauce ( US) soya sauce ( Commonwealth) shoyu ( Japan) or sillao ( Peru) is a fermented Sauce The term is also sometimes used to refer to any chemical mixing process.
Brewing has a very long history, and archeological evidence suggests that this technique was used in ancient Egypt. The history of Egypt is the longest continuous history as a unified state of any country in the world Descriptions of various beer recipes can be found in Sumerian writings, some of the oldest known writing of any sort. A recipe is a set of instructions that show how to prepare or make something especially a culinary dish. Sumer ( Sumerian: sux-Latn [[Ki (earth ki]]-[[EN (cuneiform en]]-'''ĝir15''', Akkadian: Šumeru; possibly Biblical Shinar
The brewing industry is part of most western economies. Beer is the world's oldest and most widely consumed Alcoholic beverage and the third most popular drink overall after water and tea
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Brewing beer
All beers are brewed using a process based on a simple formula. Malting is a process applied to Cereal grains in which the grains are made to Germinate by soaking in water and are then quickly halted from germinating further Hops are the female Flower cones of the hop plant ( Humulus lupulus) A hopback, used in the brewing of Beer, is a sealed chamber that is inserted in between the brewing kettle and counter-flow wort chiller Cask ale or cask-conditioned beer is the term for unfiltered and unpasteurised Beer which is conditioned (including Secondary fermentation Key to the process is malted grain--depending on the region, traditionally barley, wheat or sometimes rye. Malting is a process applied to Cereal grains in which the grains are made to Germinate by soaking in water and are then quickly halted from germinating further Barley ( Hordeum vulgare) is an annual Cereal Grain, which serves as a major animal Feed crop, with smaller amounts used for Wheat ( Triticum spp is a worldwide cultivated grass from the Levant area of the Middle East. Rye ( Secale cereale) is a grass grown extensively as a grain and forage crop (When malting rye, due care must be taken to prevent ergot poisoning (ergotism), as rye is particularly prone to developing this toxic fungus during the malting process. Ergot is the common name of a Fungus in the Genus Claviceps that is parasitic on certain grains and grasses Ergotism is the effect of long-term Ergot Poisoning traditionally due to the Ingestion of the Alkaloids produced by the Claviceps purpurea )
Malt is made by allowing a grain to germinate, after which it is then dried in a kiln and sometimes roasted. Malting is a process applied to Cereal grains in which the grains are made to Germinate by soaking in water and are then quickly halted from germinating further Germination is the process whereby growth emerges from a period of dormancy Kilns are thermally insulated chambers or Ovens in which controlled temperature regimes are produced The germination process creates a number of enzymes, notably α-amylase and β-amylase, which will be used to convert the starch in the grain into sugar. Enzymes are Biomolecules that catalyze ( ie increase the rates of Chemical reactions Almost all enzymes are Proteins α-Amylase is the major form of Amylase found in humans and other mammals Depending on the amount of roasting, the malt will take on a dark colour and strongly influence the colour and flavour of the beer.
The malt is crushed to break apart the grain kernels, increase their surface area, and separate the smaller pieces from the husks. The resulting grist is mixed with heated water in a vat called a "mash tun" for a process known as "mashing". For the publication see Grist Magazine. Grist is Grain that has been separated from its Chaff in preparation for grinding Water is a common Chemical substance that is essential for the survival of all known forms of Life. In Brewing and Distilling, mashing is the process of combining a mix of milled Grain (typically Malted Barley with supplementary 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. Enzymes are Biomolecules that catalyze ( ie increase the rates of Chemical reactions Almost all enzymes are Proteins Starch, CAS # 9005-25-8 Chemical formula (C6H10O5n is a Polysaccharide Sugar is a class of edible Crystalline substances mainly Sucrose, Lactose, and Fructose. Mashing usually takes 1 to 2 hours, and during this time various temperature rests (waiting periods) activate different enzymes depending upon the type of malt being used, its modification level, and the desires of the brewmaster. Temperature is a physical property of a system that underlies the common notions of hot and cold something that is hotter generally has the greater temperature A brewery is a dedicated building for the making of Beer, though beer can be made in the home and has been for much of beer's history The activity of these enzymes convert the starches of the grains to dextrins and then to fermentable sugars such as maltose. Dextrins are a group of low-molecular-weight Carbohydrates produced by the Hydrolysis of Starch. Maltose, or malt sugar is a Disaccharide formed from two units of Glucose joined with an α(1→4 linkage The mash tun generally contains a slotted "false bottom" or other form of manifold which acts as a strainer allowing for the separation of the liquid from the grain.
A mash rest from 49-55°C (120-130°F) activates various proteinases, which break down proteins that might otherwise cause the beer to be hazy. A protease is any Enzyme that conducts Proteolysis, that is begins protein Catabolism by Hydrolysis of the Peptide bonds that link But care is of the essence since the head on beer is also composed primarily of proteins, so too aggressive a protein rest can result in a beer that cannot hold a head. This rest is generally used only with undermodified (i. e. undermalted) malts which are decreasingly popular in Germany and the Czech Republic, or non-malted grains such as corn and rice, which are widely used in North American beers. Germany, officially the Federal Republic of Germany ( ˈbʊndəsʁepuˌbliːk ˈdɔʏtʃlant is a Country in Central Europe. The Czech Republic ( ˈt͡ʃɛskaː ˈrɛpuˌblɪka short form in Česko ˈt͡ʃɛskɔ also called Czechia, Maize (ˈmeɪz ( Zea mays L. ssp mays) known as corn in some countries is a cereal grain domesticated in Mesoamerica Rice is a Cereal foodstuff which forms an important part of the diet of many people worldwide and as such it is a staple food for many A mash rest at 60°C (140°F) activates beta-glucanase, which breaks down gummy beta-glucans in the mash, making the sugars flow out more freely later in the process. In the modern mashing process commercial fungal based beta-glucanase may be added as a supplement. Finally, a mash rest temperature of 65-71°C (149-160°F) is used to convert the starches in the malt to sugar, which is then usable by the yeast later in the brewing process. Doing the latter rest at the lower end of the range produces more low-order sugars which are more fermentable by the yeast. Yeasts are a growth form of eukaryotic Microorganisms classified in the kingdom Fungi, with about 1500 Species currently described This in turn creates a beer lower in body and higher in alcohol. A rest closer to the higher end of the range creates more higher-order sugars which are less fermentable by the yeast, so a fuller-bodied beer with less alcohol is the result.
After the mashing, the resulting liquid is strained from the grains in a process known as lautering. Liquid is one of the principal States of matter. A liquid is a Fluid that has the particles loose and can freely form a distinct surface at the boundaries of Lautering is a process in Brewing Beer in which the mash is separated into the clear liquid Wort and the residual grain Prior to lautering, the mash temperature may be raised to about 75 °C (165-170 °F) (known as a mashout) to deactivate enzymes. Additional water may be sprinkled on the grains to extract additional sugars (a process known as sparging).
At this point the liquid 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. A kettle is a Kitchenware piece Depending on culture and historical location in the context of bathware the word kettle can have a variety of meanings Hops are the female Flower cones of the hop plant ( Humulus lupulus) A(n herb (ˈhɝb or /ˈɝb/ see pronunciation differences) is a plant that is valued for qualities such as medicinal properties flavor scent or the like The boiling process serves to terminate enzymatic processes, precipitate proteins, isomerize hop resins, concentrate and sterilize the wort. Precipitation is the formation of a Solid in a Solution during a Chemical reaction. In Chemistry isomerisation is the process by which one Molecule is transformed into another molecule which has exactly the same atoms but the atoms are rearranged Resin, not to be confused with Rosin, is a Hydrocarbon Secretion of many Plants particularly coniferous trees. Sterilization (or sterilisation, see spelling differences) refers to any process that effectively kills or eliminates transmissible agents (such as Fungi Hops add flavour, aroma and bitterness to the beer. Taste (or more formally gustation) is a form of direct Chemoreception and is one of the traditional five Senses 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. Yeasts are a growth form of eukaryotic Microorganisms classified in the kingdom Fungi, with about 1500 Species currently described The yeast converts the sugars from the malt into alcohol, carbon dioxide and other components through a process called Glycolysis. Carbon dioxide ( Chemical formula:) is a Chemical compound composed of two Oxygen Atoms covalently bonded to a single See also Gluconeogenesis, which carries out a process wherein glucose is synthesized rather than catabolized After a week to three weeks, the fresh (or "green") beer is run off into conditioning tanks. After conditioning for a week to several months, the beer is often filtered to remove yeast and particulates. The "bright beer" is then ready for serving or packaging.
There are four main families of beer styles determined by the variety of yeast used in their brewing. Beer style is a term used to differentiate and categorize Beers by various factors such as colour flavour strength ingredients production method recipe history or origin
Ale (top-fermenting yeasts)
Ale yeasts ferment at warmer temperatures between 15-20°C (60-68°F), and occasionally as high as 24°C (75°F). Beer style is a term used to differentiate and categorize Beers by various factors such as colour flavour strength ingredients production method recipe history or origin Ale is a type of Beer brewed from Malted Barley using a top-fermenting Brewers' yeast. Ale is a type of Beer brewed from Malted Barley using a top-fermenting Brewers' yeast. Pure ale yeasts form a foam on the surface of the fermenting beer, because of this they are often referred to as top-fermenting yeast—though there are some British ale yeast strains that settle at the bottom. Ales are generally ready to drink within three weeks after the beginning of fermentation, however, some styles benefit from additional aging for several months or years. Ales range in colour from very pale to black opaque. England is best known for its variety of ales. Ale yeasts can be harvested from the primary fermenter, and stored in the refrigerator.
Lager (bottom-fermenting yeasts)
While the nature of yeast was not fully understood until Emil Hansen of the Carlsberg brewery in Denmark isolated a single yeast cell in the 1800s, brewers in Bavaria had for centuries been selecting these cold-fermenting lager yeasts by storing (lagern) their beers in cold alpine caves. Lager (storage camp bearing etc is the more popular of two main types of Beer; the other being Ale. Emil Christian Hansen ( May 8, 1842 – August 27, 1909) was a Danish Mycologist and fermentation physiologist The Carlsberg Group (ˈkɑrlzbɚɡ is a large Brewing company founded in 1847 by J The Kingdom of Denmark ( ˈd̥ænmɑɡ̊ (archaic ˈd̥anmɑːɡ̊ commonly known as Denmark, is a country in the Scandinavian region of northern Europe Bavaria ( German:, with an area of 70553 Km² (27241 square miles and almost 12 A cave is a natural underground void large enough for a human to enter The process of natural selection meant that the wild yeasts that were most cold tolerant would be the ones that would remain actively fermenting in the beer that was stored in the caves. Some of these Bavarian yeasts were stolen and brought back to the Carlsberg brewery around the time that Hansen did his famous work.
Lager yeast tends to collect at the bottom of the fermenter and is often referred to as bottom-fermenting yeast. Lager is fermented at much lower temperatures, around 10°C (50°F), compared to typical ale fermentation temperatures of 18°C (65°F). It is then stored for 30 days or longer close to freezing point. For freezing as a method of food preservation see Frozen food. During storage, the beer mellows and flavours become smoother. Sulfur components developed during fermentation dissipate. Sulfur or sulphur (ˈsʌlfɚ see spelling below) is the Chemical element that has the Atomic number 16 The popularity of lager was a major factor that led to the rapid introduction of refrigeration in the early 1900s. Refrigeration is the process of removing Heat from an enclosed space or from a substance and moving it to a place where it is unobjectionable
Today, lagers represent the vast majority of beers produced, the most famous being a light lager called Pilsner which originated in Pilsen, Czech Republic (Plzeň in Czech). Pilsner, sometimes pilsener or simply pils, is a Pale lager, developed in the 19th century in the city of Pilsen, Bohemia ( The Czech Republic ( ˈt͡ʃɛskaː ˈrɛpuˌblɪka short form in Česko ˈt͡ʃɛskɔ also called Czechia, Czech (ˈʧɛk čeština ˈʧɛʃcɪna in Czech is a West Slavic language with about 12 million native speakers it is the majority language in the It is a common misconception that all lagers are light in color—lagers can range from very light to deep black, just like ales.
Beers of Spontaneous Fermentation (wild yeasts)
These beers are nowadays primarily only brewed around Brussels, Belgium. Lambic is a very distinctive type of Beer brewed only in the Pajottenland region of Belgium (southwest of Brussels) They are fermented by means of wild yeast strains that live in a part of the Zenne river which flows through Brussels. These beers are also called Lambic beers. Lambic is a very distinctive type of Beer brewed only in the Pajottenland region of Belgium (southwest of Brussels) However with the advent of yeast banks and the National Collection of Yeast Cultures,[1] brewing these beers, although not through spontaneous fermentation, is possible anywhere.
Beers of mixed origin
These beers are blends of spontaneous fermentation beers and ales or lagers or they are ales/lagers which are also fermented by wild yeasts.
The brewing process
Work in the brewery is typically divided into 7 steps: mashing, lautering, boiling, fermenting, conditioning, filtering, and filling. In Brewing and Distilling, mashing is the process of combining a mix of milled Grain (typically Malted Barley with supplementary Lautering is a process in Brewing Beer in which the mash is separated into the clear liquid Wort and the residual grain Fermentation in Food processing typically refers to the conversion of Sugar to Alcohol using Yeast under Anaerobic conditions
HERMS is an acronym for a type of brewing system, particularly in homebrewing, which stands for Heat Exchange Recirculating Mash System. Acronyms, initialisms, and alphabetisms are Abbreviations that are formed using the initial components in a phrase or name Homebrewing typically refers to the Brewing of Beer and similar Alcoholic beverages (and sometimes soft drinks on a very small scale as a Hobby The basic premise is that liquid wort is drawn off from the mash and passed through a heat exchanger before returning to the mash. A heat exchanger is a device built for efficient Heat transfer from one medium to another whether the media are separated by a solid wall so that they never mix or the media It is widely (although not universally) accepted that this process speeds starch conversion, clarifies runoff and greatly reduces temperature stratification within the mash. Starch conversion is the process (especially in Brewing) whereby unfermentable Starch is converted into fermentable Sugars, either by
Mashing
Mashing is the process of mixing milled grain (typically malted grain) with water, and heating this mixture up which rests at certain temperatures to allow enzymes in the malt to break down the starch in the grain into sugars, typically maltose. In Brewing and Distilling, mashing is the process of combining a mix of milled Grain (typically Malted Barley with supplementary Malting is a process applied to Cereal grains in which the grains are made to Germinate by soaking in water and are then quickly halted from germinating further Enzymes are Biomolecules that catalyze ( ie increase the rates of Chemical reactions Almost all enzymes are Proteins Starch, CAS # 9005-25-8 Chemical formula (C6H10O5n is a Polysaccharide Sugar is a class of edible Crystalline substances mainly Sucrose, Lactose, and Fructose. Maltose, or malt sugar is a Disaccharide formed from two units of Glucose joined with an α(1→4 linkage
Lautering
Lautering is the separation of the extracts wort during mashing from the spent grain. The Boston Beer Company ( is an American Brewing company founded in 1985 by Jim Koch in Boston Massachusetts, USA. Lautering is a process in Brewing Beer in which the mash is separated into the clear liquid Wort and the residual grain 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. A Lauter tun is the traditional vessel used for separation of the extracted wort 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.
Lauter tun
A lauter tun is a special container used in all-grain brewing for separating the sweet wort from the spent grains (malted barley etc. A Lauter tun is the traditional vessel used for separation of the extracted wort ). In essence it is simply a large strainer. It can be as simple as a plastic bucket with holes in the bottom or as complex as a stainless steel kettle with a specialized straining device attached to a spigot welded into the side of the kettle.
Sparging is the rinsing of the grains with water and is most often conducted in a lauter tun. Lautering is a process in Brewing Beer in which the mash is separated into the clear liquid Wort and the residual grain
Mash filter
A mash filter is a plate-and-frame filter. The empty frames contain the mash, including the spent grains, and have a capacity of around one hectoliter. The litre or liter (see spelling differences) is a unit of Volume. The plates contain a support structure for the filter cloth. The plates, frames, and filter cloths are arranged in a carrier frame like so: frame, cloth, plate, cloth, with plates at each end of the structure. Newer mash filters have bladders that can press the liquid out of the grains between spargings. The grain does not act like a filtration medium in a mash filter.
Boiling
Boiling the malt extracts, called wort, ensures its sterility, and thus prevents a lot of infections. During the boil hops are added, which contribute bitterness, flavour, and aroma compounds to the beer, and, along with the heat of the boil, causes proteins in the wort to coagulate and the pH of the wort to fall. pH is the measure of the acidity or alkalinity of a Solution. Finally, the vapours produced during the boil volatilise off flavours, including dimethyl sulfide precursors. Dimethyl sulfide (DMS or methylthiomethane is an organosulfur compound with the formula (CH32S
The boil must be conducted so that is it even and intense. The boil lasts between 50 and 120 minutes, depending on its intensity, the hop addition schedule, and volume of wort the brewer expects to evaporate.
Boiling equipment
The simplest boil kettles are direct-fired, with a burner underneath. These can produce a vigorous and favourable boil, but are also apt to scorch the wort where the flame touches the kettle, causing caramelization and making clean up difficult.
Most breweries use a steam-fired kettle, which uses steam jackets in the kettle to boil the wort. The steam is delivered under pressure by an external boiler.
State-of-the-art breweries today use many interesting boiling methods, all of which achieve a more intense boiling and a more complete realisation of the goals of boiling.
Many breweries have a boiling unit outside of the kettle, sometimes called a calandria, through which wort is pumped. The unit is usually a tall, thin cylinder, with many tubes upwards through it. These tubes provide an enormous surface area on which vapor bubbles can nucleate, and thus provides for excellent volitization. The total volume of wort is circulated seven to twelve times an hour through this external boiler, ensuring that the wort is evenly boiled by the end of the boil. The wort is then boiled in the kettle at atmospheric pressure, and through careful control the inlets and outlets on the external boiler, an overpressure can be achieved in the external boiler, raising the boiling point by a few Celsius degrees. Upon return to the boil kettle, a vigorous vaporization occurs. The higher temperature due to increased vaporization can reduce boil times up to 30%. External boilers were originally designed to improve performance of kettles which did not provide adequate boiling effect, but have since been adopted by the industry as a sole means of boiling wort.
Modern brewhouses can also be equipped with internal calandria, which requires no pump. It works on basically the same principle as external units, but relies on convection to move wort through the boiler. This can prevent overboiling, as a deflector above the boiler reduces foaming, and also reduces evaporation. Internal calandria are generally difficult to clean.
Energy recovery
Boiling wort takes a lot of energy, and it is wasteful to let this energy escape into the atmosphere. The simplest way to recover this energy is with a kettle vapor condenser (German: Pfaduko, from the much longer Pfannendunstkondensator). A kettle vapor condenser is often nothing more than a plate heat exchanger.
Whirlpooling
At the end of the boil, the wort is set into a whirlpool. The so-called teacup effect forces the more dense solids (coagulated proteins, vegetable matter from hops) into a cone in the center of the whirlpool tank.
In most large breweries, there is a separate tank for whirlpooling. These tanks have a large diameter to encourage settling, a flat bottom, a tangential inlet near the bottom of the whirlpool, and an outlet on the bottom near the outer edge of the whirlpool. A whirlpool should have no internal protrusions that might slow down the rotation of the liquid. The bottom of the whirlpool is often slightly sloped towards the outlet. Newer whirlpools often have "Denk rings" suspended in the middle of the whirlpool. These rings are aligned horizontally and have about 75% of the diameter of the whirlpool. The Denk rings prevent the formation of secondary eddies in the whirlpool, encouraging the formation of a cohesive trub cone in the middle of the whirlpool. Smaller breweries often use the brewkettle as a whirlpool. In the United Kingdom, it is common practice to use a device known as a hopback to clear the green wort (green wort is wort to which yeast has not yet been added). This device has the same effect as, but operates in a completely different manner than, a whirlpool. The two devices are often confused but are in function, quite different. While a whirlpool functions through the use of centrifugal forces, a hopback uses a layer of fresh hop flowers in a confined space to act as a filter bed to remove trub (pronounced tr-oo-b, tr-uh-b in the UK). Furthermore, while a whirlpool is only useful for the removal of pelleted hops (as flowers don't tend to separate as easily), hopbacks are generally used only for the removal of whole flower hops (as the particles left by pellets tend to make it through the hopback. )
In homebrewing, where a brewer has the power to lift the entire stock and manipulate it by hand; the process of trub removal (the process addressed by the whirlpool and hopback) is generally accomplished by simply allowing the trub to settle to the bottom of the brew kettle and slowly decanting the green wort from the top so as not to disturb the thin layer of trub. Siphoning may also be employed but this is rare.
Wort cooling
After the whirlpool, the wort must be brought down to fermentation temperatures before yeast is added. In modern breweries this is achieved through a plate heat exchanger. A heat exchanger is a device built for efficient Heat transfer from one medium to another whether the media are separated by a solid wall so that they never mix or the media A plate heat exchanger has many ridged plates, which form two separate paths. The wort is pumped into the heat exchanger, and goes through every other gap between the plates. The cooling medium, usually water, goes through the other gaps. The ridges in the plates ensure turbulent flow. A good heat exchanger can drop 95 °C wort to 20 °C while warming the cooling medium from about 10 °C to 80 °C. The last few plates often use a cooling medium which can be cooled to below the freezing point, which allows a finer control over the wort-out temperature, and also enables cooling to around 10 °C. Freezing Point (Chinese 冰點 Bīngdiǎn is a news journal in the People's Republic of China which has been the subject of controversy over its criticism After cooling, oxygen is often dissolved into the wort to revitalize the yeast and aid its reproduction.
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. Malting is a process applied to Cereal grains in which the grains are made to Germinate by soaking in water and are then quickly halted from germinating further Carbon dioxide ( Chemical formula:) is a Chemical compound composed of two Oxygen Atoms covalently bonded to a single 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. A silo is a structure for storing bulk materials. Silos are used in Agriculture to store grain (see Grain elevators or fermented feed A gallon is a measure of Volume. It is in current use in the United States and still has limited use in many other English-speaking countries A carboy is a container for fluids Brewing In Brewing, a carboy is also known as a demijohn.
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. Only 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. Carbon (kɑɹbən is a Chemical element with the symbol C and its Atomic number is 6 Oxygen (from the Greek roots ὀξύς (oxys (acid literally "sharp" from the taste of acids and -γενής (-genēs (producer literally begetteris the Carbon dioxide ( Chemical formula:) is a Chemical compound composed of two Oxygen Atoms covalently bonded to a single 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.
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.
Often, the beer is then racked (siphoned) into another container, usually a carboy, for aging or secondary fermentation. A siphon (also spelled syphon) is a continuous tube that allows liquid to drain from a reservoir through an intermediate point that is higher than the reservoir the flow being A carboy is a container for fluids Brewing In Brewing, a carboy is also known as a demijohn. Fermentation is virtually complete, so the term secondary fermentation actually refers to conditioning. Use of a hydrometer is recommended to be absolutely sure all fermentation is finished; this is especially important as a precaution when the beer is to be bottled. A hydrometer is an instrument used to measure the Specific gravity (or Relative density) of Liquids that is the ratio Racking is done to separate the beer from the trub so that the remaining active yeasts do not consume it, as this can give the beer an off-flavor. Racking also helps separate the beer from sediment, making it less likely to find its way into the finished product. During secondary fermentation some chemical byproducts from the primary fermentation are digested, which considerably improves the taste. Secondary fermentation can take from 2 to 4 weeks, sometimes longer, depending on the type of beer. Additionally lagers, at this point, are aged at near freezing temperatures for 1-6 months depending on style. Pale lager is a very pale to golden -coloured Beer with a well attenuated body and noble hop bitterness This cold aging serves to reduce sulfur compounds produced by the bottom-fermenting yeast and to produce a cleaner tasting final product with fewer esters. Sulfur or sulphur (ˈsʌlfɚ see spelling below) is the Chemical element that has the Atomic number 16 Esters are a class of Chemical compounds and Functional groups Esters consist of an inorganic or organic Acid in which at least
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. This is where aging occurs.
Filtering
Filtering the beer stabilizes the flavour, and gives beer its polished shine and brilliance. Filtered or bright beer is Beer in which yeast is no longer in suspension. 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. Diatomaceous earth (ˌdaɪətəˈmeɪʃəs ˈɝθ also known as DE, TSS, diatomite, diahydro, kieselguhr, kieselgur and
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.
Sheet (pad) filters
These filters use pre-made media and are relatively straightforward. The sheets are manufactured to allow only particles smaller than a given size through, and the brewer is free to choose how finely to filter the beer. The sheets are placed into the filtering frame, sterilized (with hot water, for example) and then used to filter the beer. The sheets can be flushed if the filter becomes blocked, and usually the sheets are disposable and are replaced between filtration sessions. Often the sheets contain powdered filtration media to aid in filtration.
It should be kept in mind that pre-made filters have two sides. One with loose holes, and the other with tight holes. Flow goes from the side with loose holes to the side with the tight holes, with the intent that large particles get stuck in the large holes while leaving enough room around the particles and filter medium for smaller particles to go through and get stuck in tighter holes.
Sheets are sold in nominal ratings, and typically 90% of particles larger than the nominal rating are caught by the sheet.
Kieselguhr filters
Filters that use a powder medium are considerably more complicated to operate, but can filter much more beer before needing to be regenerated. Common media include diatomaceous earth, or kieselguhr, and perlite. Diatomaceous earth (ˌdaɪətəˈmeɪʃəs ˈɝθ also known as DE, TSS, diatomite, diahydro, kieselguhr, kieselgur and Perlite is an Amorphous Volcanic Glass that has a relatively high Water content typically formed by the hydration of Obsidian
Packaging
Packaging is putting the beer into the containers in which it will leave the brewery. Typically this means in bottles, aluminium cans and kegs, but it might include bulk tanks for high-volume customers. A keg is a cylindrical container usually constructed of aluminum steel or wood
Secondary fermentation
Secondary fermentation is an additional fermentation after the first or primary fermentation. Secondary fermentation is a process commonly associated with Winemaking, which entails a second period of fermentation in a different vessel than what was used For the secondary fermentation, the beer is transferred to a second fermenter, so that it is no longer exposed to the dead yeast and other debris (also known as "trub") that have settled to the bottom of the primary fermenter. This prevents the formation of unwanted flavors and harmful compounds such as acetylaldehydes, which are commonly blamed for hangovers. Acetaldehyde, sometimes known as ethanal, is an organic chemical compound with the formula C[[Hydrogen H]]3CH O or MeCHO
Among homebrewers, secondary fermentation is a common source of discussion and debate. Some believe that the majority of homebrewed beers can simply be fermented in a single fermenter for approximately two weeks and then bottled, making secondary fermentation unnecessary. However, secondary fermentation is a necessary step when brewing beers with long fermentation times, such as lagers. Many homebrewers use secondary fermentation as a way of Conditioning, to enhance both the flavor and appearance of the beer. Homebrewing typically refers to the Brewing of Beer and similar Alcoholic beverages (and sometimes soft drinks on a very small scale as a Hobby [1]
During secondary fermentation, most of the remaining yeast will settle to the bottom of the second fermenter, yielding a less hazy product. Some beers may have three fermentations, the third being the bottle fermentation.
Bottle fermentation
- See Bottle conditioning. Bottle conditioned beers are either unfiltered so the final conditioning of the beer takes place in the bottle or filtered and then reseeded with yeast so that an additional
Most homebrewed beers undergo a fermentation in the bottle, giving natural carbonation. This may be a second or third fermentation. They are bottled with a viable yeast population in suspension. Yeasts are a growth form of eukaryotic Microorganisms classified in the kingdom Fungi, with about 1500 Species currently described If there is no residual fermentable sugar left, sugar may be added. The resulting fermentation generates CO2 which is trapped in the bottle, remaining in solution and providing natural carbonation. Carbon dioxide ( Chemical formula:) is a Chemical compound composed of two Oxygen Atoms covalently bonded to a single
Cask conditioning
- See Cask ale. Cask ale or cask-conditioned beer is the term for unfiltered and unpasteurised Beer which is conditioned (including Secondary fermentation
Beer in casks are managed carefully to allow some of the carbonation to escape.
See also
- Beer fault
- Distilling
- Brewery
- Homebrewing
- History of beer
- Mead, honey mead and meadmaking
- The British Beer and Pub Association
References
External links
- Home brewing
- Brewery History Society promotes research in the brewing industry, and collects information about brewery history. Distillation is a method of separating Mixtures based on differences in their volatilities in a boiling liquid mixture A brewery is a dedicated building for the making of Beer, though beer can be made in the home and has been for much of beer's history Homebrewing typically refers to the Brewing of Beer and similar Alcoholic beverages (and sometimes soft drinks on a very small scale as a Hobby See also Beer Beer is one of the world's oldest beverages with the history of beer dating back to the 6th millennium BC and being recorded in the written history of Mead (ˈmiːd is a fermented Alcoholic beverage made of Honey, Water, and Yeast.
- The River Wey and Wey Navigations Community Site — a site about the Wey Valley including information about the history of Brewing in southern England
- The British Library - finding information about the brewing industry
- interactive Flowsheets on beer brewing
- An overview of the microbiology behind beer brewing from the Science Creative Quarterly
- Brewing news page - Alcohol and Drugs History Society
- Carling Brewing Process
- Hyfoma on beer brewing - Hyfoma
- The Brewers' Handbook The Complete Book to Brewing Beer. The Alcohol and Drugs History Society is a scholarly organization whose members study the history of a variety of illegal regulated and unregulated Drugs such as Opium Hyfoma stands for hygienic food manufacturingIt was the name of an old project from TNO the Netherlands
- Cat's Meow Collection Internet recipes compiled as of 1997
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