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A 16th-century brewery

Brewing is the production of alcoholic beverages and alcohol fuel through fermentation. The term is used for the production of beer, although the word "brewing" is also used to describe the fermentation process used to create wine and mead. It can also refer to the process of producing sake and soy sauce. "Brewing" is also sometimes used to refer to any chemical mixing process.

Brewing specifically refers to the process of steeping, such as with tea and water, and extraction, usually through heat. Wine and cider technically aren't brewed, rather vinted, as the entire fruit is pressed, and then the liquid extracted. Mead isn't technically brewed, as heating often isn't used in the mixing process, and the honey is used entirely, as opposed to being heated with water, and then discarded, as are hops and barley in beer, and or tea leaves for tea, and coffee beans for coffee. Spices could technically be brewed into a mead though.

Brewing has a very long history, and archeological evidence suggests that this technique was used in ancient Egypt. Descriptions of various beer recipes can be found in Sumerian writings, some of the oldest known writing of any sort.

The brewing industry is part of most western economies.

Contents

The brewing process

There are nine major steps in the brewing process, which include malting, milling, mashing, brewing, cooling, fermentation, racking and finishing.

Malting is the process where the barley grain is made ready for brewing. Malting is broken down into three steps, which help to release the starches in the barley. First, during steeping, the grain is added to a vat with water and allowed to soak for approximately 40 hours. During germination, the grain is spread out on the floor of the germination room for around 5 days. The goal of germination is to allow the starches to in the barley grain to breakdown into shorter lengths. When this step is complete, the grain is referred to as green malt. The final part of malting is kilning. Here, the green malt goes through a very high temperature drying in a kiln. The temperature change is gradual so as not to disturb or damage the enzymes in the grain. When kilning is complete, there is a finished malt as a product.[1]

The next step in the brewing process is milling. This is when the grains that are going to be used in a batch of beer are cracked. Milling the grains makes it easier for them to absorb the water that they are mixed with and which extracts sugars from the malt.[2] Milling can also influence the general characteristics of a beer.[3]

Mashing is the next step in the process. This process converts the starches released during the malting stage, into sugars that can be fermented. The milled grain is dropped into hot water in a large vessel known as a mash tun. In this vessel, the grain and water are mixed together to create a cereal mash. The leftover sugar rich water is then strained through the bottom of the mash, and is now referred to as wort.[4]

Brewing is the next step in the cycle. Here, the wort goes to the brew kettle or boiler, where it is brought to a boil. This stage is where many chemical and technical reactions take place, and where important decisions about the flavor, color, and aroma of the beer are made.[5] Hops may be added throughout the boiling process for bitterness and/or aroma. At the conclusion of the boiling, the wort is often set into a whirlpool, where the more solid particles in the wort are separated out.[6]

After the whirlpool, the wort then begins the process of cooling. This is when the wort is transferred rapidly from the whirlpool or brew kettle to a heat exchanger to be cooled. The heat exchanger consists of tubing inside a tub of cold water. It is very important to quickly cool the wort to a level where yeast can be added safely.[2] Yeast is unable to grow in high temperatures.[5]

After the wort goes through the heat exchanger, the cooled wort goes into a fermentation tank. A type of yeast is selected and also added to the fermentation tank.[5] When the yeast is added to the wort, the process of the yeast fermenting the wort sugars into alcohol begins.[7]

The second to last stage in the brewing process is called racking. This is when the brewer racks the beer into a new tank, called a conditioning tank.[4] Conditioning of the beer is the process in which the beer ages, the flavor becomes smoother, and flavors that are unwanted dissipate.[6]

Finally, the beer enters the finishing stage.[2] Here, beers that require filtration are filtered, and given their natural polish and color. Filtration also helps to stabilize the flavor of the beer.[4] After the beer is filtered, it undergoes carbonation, and is then moved to a holding tank until bottling.

Brewing beer

Diagram illustrating the process of brewing beer
Hot Water Tank
Chiller
Cask or Keg

All beers are brewed using a process based on a simple formula. Key to the process is malted grain—depending on the region, traditionally barley, wheat or sometimes rye. (When malting rye, due care must be taken to prevent ergot poisoning (ergotism), as rye is particularly prone to be infected by this toxic fungus.)

Malt is made by allowing a grain to germinate, after which it is then dried in a kiln and sometimes roasted. The germination process creates a number of enzymes, notably α-amylase and β-amylase, which convert the starch in the grain into sugar. 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, expose the cotyledon which contains the majority of the carbohydrates and sugars, 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". 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, 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. The activity of these enzymes convert the starches of the grains to dextrins and then to fermentable sugars such as maltose. In smaller breweries, 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 (120–131 °F) activates various proteases, which break down proteins that might otherwise cause the beer to be hazy. 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. A mash rest at 60 °C (140 °F) activates β-glucanase, which breaks down gummy β-glucans in the mash, making the sugars flow out more freely later in the process. In the modern mashing process, commercial fungal based β-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 favors β-amylase enzymes, producing more low-order sugars like maltotriose, maltose, and glucose which are more fermentable by the yeast. This in turn creates a beer lower in body and higher in alcohol. A rest closer to the higher end of the range favors α-amylase enzymes, creating more higher-order sugars and dextrins which are less fermentable by the yeast, so a fuller-bodied beer with less alcohol is the result. Duration and pH variances also affect the sugar composition of the resulting wort.[8]

After the mashing, the resulting liquid is strained from the grains in a process known as lautering. 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. The boiling process serves to terminate enzymatic processes, precipitate proteins, isomerize hop resins, concentrate 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 fermentation. After one 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.

Ale (top-fermenting yeasts)

Ale yeasts ferment at warmer temperatures between 15–20 °C (59–68 °F), and occasionally as high as 24 °C (75 °F). 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 an opaque black. England is best known for its variety of ales. Ale yeasts can be harvested from the primary fermenter, and stored in the refrigerator or freezer.

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. 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 brought back to the Carlsberg brewery around the time that Hansen did his famous work.

Traditionally, ales and lagers have been differentiated as being either a top fermentor or bottom fermentor, respectively. But, as the years go by homebrewers and microbrewers alike keep pushing the envelope of the craft these distinctions are beginning to blur. The main difference between the two is lager yeast's ability to process raffinose. Raffinose is a trisaccharide composed of galactose, fructose, and glucose.

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 (64 °F). It is then stored for 30 days or longer close to freezing point. During storage, the beer mellows and flavours become smoother. Sulfur components developed during fermentation dissipate. 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 Pilsen, Czech Republic (Plzeň in Czech). 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. 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. However, with the advent of yeast banks and the National Collection of Yeast Cultures,[9] brewing these beers, although not through spontaneous fermentation, is possible anywhere.

Beers of mixed origin

These beers are blends of spontaneous fermentation or they are ales/lagers which are also fermented by wild yeasts.

Ingredients

Malted barley before roasting

The basic ingredients of beer are water; a starch source, such as malted barley, able to be fermented (converted into alcohol); a brewer's yeast to produce the fermentation; and a flavouring such as hops.[10] A mixture of starch sources may be used, with a secondary starch source, such as maize (corn), rice or sugar, often being termed an adjunct, especially when used as a lower-cost substitute for malted barley.[11] Less widely used starch sources include millet, sorghum and cassava root in Africa, potato in Brazil, and agave in Mexico, among others.[12] The amount of each starch source in a beer recipe is collectively called the grain bill.

Water

Beer is composed mostly of water. Regions have water with different mineral components; as a result, different regions were originally better suited to making certain types of beer, thus giving them a regional character.[13] For example, Dublin has hard water well suited to making stout, such as Guinness; while Pilzen has soft water well suited to making pale lager, such as Pilsner Urquell.[13] The waters of Burton in England contain gypsum, which benefits making pale ale to such a degree that brewers of pale ales will add gypsum to the local water in a process known as Burtonisation.[14]

Starch source

The starch source in a beer provides the fermentable material and is a key determinant of the strength and flavour of the beer. The most common starch source used in beer is malted grain. Grain is malted by soaking it in water, allowing it to begin germination, and then drying the partially germinated grain in a kiln. Malting grain produces enzymes that convert starches in the grain into fermentable sugars.[15] Different roasting times and temperatures are used to produce different colours of malt from the same grain. Darker malts will produce darker beers.[16]

Nearly all beer includes barley malt as the majority of the starch. This is because of its fibrous husk, which is not only important in the sparging stage of brewing (in which water is washed over the mashed barley grains to form the wort), but also as a rich source of amylase, a digestive enzyme which facilitates conversion of starch into sugars. Other malted and unmalted grains (including wheat, rice, oats, and rye, and less frequently, corn and sorghum) may be used. In recent years, a few brewers have produced gluten-free beer made with sorghum with no barley malt for those who cannot consume gluten-containing grains like wheat, barley, and rye.[17]

Hops

Flavouring beer is the sole major commercial use of hops.[18] The flower of the hop bine (yes, that's bine, not vine) is used as a flavouring and preservative agent in nearly all beer made today. The flowers themselves are often called "hops".

Hop cone in a Hallertau, Germany, hop yard

Hops were used by monastery breweries, such as Corvey in Westphalia, Germany, from 822 AD,[19][20] though the date normally given for widespread cultivation of hops for use in beer is the thirteenth century.[19][20] Before the thirteenth century, and until the sixteenth century, during which hops took over as the dominant flavouring, beer was flavoured with other plants; for instance, Glechoma hederacea. Combinations of various aromatic herbs, berries, and even ingredients like wormwood would be combined into a mixture known as gruit and used as hops are now used.[21] Some beers today, such as Fraoch' by the Scottish Heather Ales company[22] and Cervoise Lancelot by the French Brasserie-Lancelot company,[23] use plants other than hops for flavouring.

Hops contain several characteristics that brewers desire in beer. Hops contribute a bitterness that balances the sweetness of the malt; the bitterness of beers is measured on the International Bitterness Units scale. Hops contribute floral, citrus, and herbal aromas and flavours to beer. Hops have an antibiotic effect that favours the activity of brewer's yeast over less desirable microorganisms, and hops aids in "head retention",[24][25] the length of time that a foamy head created by carbonation will last. The acidity of hops is a preservative.[26][27]

Yeast

Yeast is the microorganism that is responsible for fermentation in beer. Yeast metabolises the sugars extracted from grains, which produces alcohol and carbon dioxide, and thereby turns wort into beer. In addition to fermenting the beer, yeast influences the character and flavour.[28] The dominant types of yeast used to make beer are ale yeast (Saccharomyces cerevisiae) and lager yeast (Saccharomyces uvarum); their use distinguishes ale and lager.[29] Brettanomyces ferments lambics,[30] and Torulaspora delbrueckii ferments Bavarian weissbier.[31] Before the role of yeast in fermentation was understood, fermentation involved wild or airborne yeasts. A few styles such as lambics rely on this method today, but most modern fermentation adds pure yeast cultures.[32]

Clarifying agent

Some brewers add one or more clarifying agents to beer, which typically precipitate (collect as a solid) out of the beer along with protein solids and are found only in trace amounts in the finished product. This process makes the beer appear bright and clean, rather than the cloudy appearance of ethnic and older styles of beer such as wheat beers.[33]

Examples of clarifying agents include isinglass, obtained from swimbladders of fish; Irish moss, a seaweed; kappa carrageenan, from the seaweed Kappaphycus cottonii; Polyclar (artificial); and gelatin.[34] If a beer is marked "suitable for Vegans", it was clarified either with seaweed or with artificial agents.[35]

The brewing process

The brewing process is typically divided into 7 steps: mashing, lautering, boiling, fermenting, conditioning, filtering, and filling.

Today, many simplified brewing systems exist which can be used at home or in restaurants. These homebrewing systems are often employed for ease of use, although some people still prefer to do the entire brewing process themselves.

Mashing

Mashing is the process of combining a mix of milled grain, known as the grist (typically malted barley with supplementary grains as maize, sorghum, rye or wheat; in a ratio of 90-10 up to 50-50), with water, and heating this mixture up with rests at certain temperatures (notably 45°C, 62°C and 73°C[36][37]) to allow enzymes in the malt to break down the starch in the grain into sugars, typically maltose.

Boilers at the Samuel Adams brewery

Wort Separation

Wort separation is the separation of the wort containing the sugar extracted during mashing from the spent grain. It can be carried out in a mash tun outfitted with a false bottom, a lauter tun, a special-purpose wide vessel with a false bottom and rotating cutters to facilitate flow, a mash filter, a plate-and-frame filter designed for this kind of separation, or in a Strainmaster. Most separation processes have 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.). In essence it is a tank with holes in the bottom small enough to hold back the large bits of grist and hulls. The bed of grist that settles on it is the actual filter. It can be as simple as a plastic bucket with holes in the bottom. Commercial lauter tuns have provision for rotating rakes or knives to cut into the bed of grist to maintain good flow. The knives can be turned so they push the grain, a feature used to drive the spent grain out of the vessel.[38]

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 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.

Strainmaster

A Strainmaster is a device invented at Anheuser Busch. It separates the wort by allowing it to flow into horizontal slotted tubes. As with a lauter tun, the actual filtration is carried out by the spent grain.

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. Finally, the vapours produced during the boil volatilise off flavours, including dimethyl sulfide precursors.

The boil must be conducted so that it is 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

Brew kettles at Coors Brewing Company.

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.

Whirlpooling

At the end of the boil, the wort is set into a whirlpool. The so-called teacup effect forces the denser 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 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 (20-26°Celsius[36]) before yeast is added. In modern breweries this is achieved through a plate heat exchanger. 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. After cooling, oxygen is often dissolved into the wort to revitalize the yeast and aid its reproduction.

Energy Recovery

While boiling, it is useful to recover some of the energy used to boil the wort. On its way out of the brewery, the steam created during the boil is passed over a coil through which unheated water flows. By adjusting the rate of flow, the output temperature of the water can be controlled. This is also often done using a plate heat exchanger. The water is then stored for later use in the next mash, in equipment cleaning, or wherever necessary.[39]

Another common method of energy recovery takes place during the wort cooling. When cold water is used to cool the wort in a heat exchanger, the water is significantly warmed. In an efficient brewery, cold water is passed through the heat exchanger at a rate set to maximize the water's temperature upon exiting. This now-hot water is then stored in a hot water tank.[40]

Fermenting

Modern fermentation tanks

After the wort is cooled and aerated — usually with sterile air — yeast is added to it, and it begins to ferment. It is during this stage that sugars won from the malt are metabolized into alcohol and carbon dioxide, and the product can be called beer for the first time. Fermentation happens in tanks which 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 cylindro-conical vessels, or CCVs, which 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.

Krausen in an English brewery's fermentation tank

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, 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 krausen 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.

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. If a separate conditioning tank is to be used, it is at this stage that the beer will be transferred into one. 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.

A similar technique is used in home brewing, wherein the beer is simply siphoned into another vessel (usually a carboy), leaving the now-dormant yeast and other sediment behind. The batch is then sometimes refrigerated for the aforementioned benefits.

Conditioning 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. 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.

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

A mixture of diatomaceous earth and yeast after 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.

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.

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.

Secondary fermentation

Secondary fermentation is an additional fermentation after the first or primary fermentation. 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.

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.[41]

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.

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. 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.

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) and served from a cask without additional nitrogen or carbon dioxide pressure.

See also

References

  1. ^ "The Ingredients of Beer". Birmingham Beverage Company. 2009. http://www.alabev.com/ingredie.htm. Retrieved 23 Nov. 2009.  
  2. ^ a b c "Ale University - Brewing Process". Merchant du Vin,. 2009. http://www.merchantduvin.com/pages/2_ale_university/aleu_brew_process.html. Retrieved 12 Nov. 2009.  
  3. ^ Charlie Papazian (30 Sept. 2009). "Beer Styles: Milling grain will influence beer character - part 11 Washington DC News, Restaurants, more by Top Local Experts, Examiner,".  
  4. ^ a b c Ted Goldammer (1 October 2008). The Brewer's Handbook: The Complete Book To Brewing Beer (2nd ed.). Apex. ISBN 0967521238.  
  5. ^ a b c "History of Beer". Foster's Group Home. http://www.fosters.com.au/enjoy/beer/history_of_beer.htm. Retrieved 22 Nov. 2009.  
  6. ^ a b I. Hornsey (2004). A History of Beer and Brewing (1st ed.). Royal Society of Chemistry. ISBN 0854046305.  
  7. ^ What is Fermentation?. WiseGEEK: clear answers for common questions. 11 Nov. 2009. http://www.wisegeek.com/what-is-fermentation.htm. Retrieved 15 Nov. 2009.  
  8. ^ Kunze, Wolfgang (2004) "Technology Brewing and Malting" VLB Berlin, ISBN 3-921690-49-8 pp.214-218
  9. ^ National Collection of Yeast Cultures
  10. ^ alabev.com The Ingredients of Beer. Retrieved 29 September 2008
  11. ^ beer-brewing.com Ted Goldammer, The Brewers Handbook, Chapter 6 - Beer Adjuncts, Apex Pub (January 1, 2000), ISBN 0-9675212-0-3. Retrieved 29 September 2008
  12. ^ BeerHunter.com Michael Jackson, A good beer is a thorny problem down Mexico way, What's Brewing, 1 Oct, 1997. Retrieved 29 September 2008
  13. ^ a b "Geology and Beer". Geotimes. 2004-08. http://www.agiweb.org/geotimes/aug04/resources.html. Retrieved 2007-11-05.  
  14. ^ [1] Michael Jackson, BeerHunter, 19 October, 1991, Brewing a good glass of water. Retrieved 13 September 2008
  15. ^ Wikisource 1911 Encyclopædia Britannica/Brewing/Chemistry. retrieved 29 September 2008
  16. ^ Farm-direct Oz, Barley Malt, 6 February 2002. Retrieved 29 September 2008
  17. ^ Smagalski, Carolyn (2006). "CAMRA & The First International Gluten Free Beer Festival". Carolyn Smagalski, Bella Online. http://www.bellaonline.com/articles/art39558.asp.  
  18. ^ A. H. Burgess, Hops: Botany, Cultivation and Utilization, Leonard Hill (1964), ISBN 0-471-12350-1
  19. ^ a b Cornell, Martyn (2003). Beer: The Story of the Pint. Headline. ISBN 0-7553-1165-5.  
  20. ^ a b Unger, Richard W. Beer in the Middle Ages and the Renaissance. pp. 54–55. ISBN 0-8122-3795-1.  
  21. ^ [2] Richard W. Unger, Beer in the Middle Ages and the Renaissance, University of Pennsylvania Press (2004), ISBN 0-8122-3795-1. Retrieved 14 September 2008.
  22. ^ "Heatherale.co.uk". Fraoch.com. http://www.fraoch.com/historicales.htm. Retrieved 2008-09-28.  
  23. ^ "La Brasserie Lancelot est située au coeur de la Bretagne, dans des bâtiments rénovés de l'ancienne mine d'Or du Roc St-André, construits au 19 ème siècle sur des vestiges néolithiques". Brasserie-lancelot.com. http://www.brasserie-lancelot.com/brasserie-lancelot.php. Retrieved 2008-09-28.  
  24. ^ "Head Retention". BrewWiki. http://www.brewwiki.com/index.php/Head_Retention. Retrieved 2007-11-05.  
  25. ^ "Hop Products: Iso-Extract". Hopsteiner. http://www.hopsteiner.com/isopg1.htm. Retrieved 2007-11-05.  
  26. ^ [3] PDQ Guides, Hops: Clever Use For a Useless Plan. retrieved 13 September 2008
  27. ^ [4], A better control of beer properties by predicting acidity of hop iso-α-acids, Blanco Carlos A.; Rojas Antonio; Caballero Pedro A.; Ronda Felicidad; Gomez Manuel; Caballero. retrieved 13 September 2008
  28. ^ Ostergaard, S., Olsson, L., Nielsen, J., Metabolic Engineering of Saccharomyces cerevisiae, Microbiol. Mol. Biol. Rev. 2000 64: 34-50
  29. ^ Google Books Paul R. Dittmer, J. Desmond, Principles of Food, Beverage, and Labor Cost Controls, John Wiley and Sons (2005), ISBN 0-471-42992-9
  30. ^ Google Books Ian Spencer Hornsey, Brewing pp221-222, Royal Society of Chemistry (1999), ISBN 0-85404-568-6
  31. ^ Web.mst.edu David Horwitz, Torulaspora delbrueckii. Retrieved 30 September 2008
  32. ^ Google Books Y. H. Hui, George G. Khachatourians, Food Biotechnology pp847-848, Wiley-IEEE (1994), ISBN 0-471-18570-1
  33. ^ "Michael Jackson's Beer Hunter — A pint of cloudy, please". Beerhunter.com. http://www.beerhunter.com/documents/19133-000717.html. Retrieved 2008-09-28.  
  34. ^ EFSA Opinion of the Scientific Panel on Dietetic Products, Nutrition and Allergies, 23/08/2007. retrieved 29 September 2008
  35. ^ Food.gov.uk Draft Guidance on the Use of the Terms ‘Vegetarian’ and ‘Vegan’ in Food Labelling: Consultation Responses pp71, 5 October 2005. retrieved 29 September 2008
  36. ^ a b "Abdijbieren. Geestrijk erfgoed" by Jef Van den Steen
  37. ^ Bier brouwen
  38. ^ Goldhammer, T. (2008) The Brewer's Handbook, 2nd edition, Apex, ISBN 978-0-9675212-3-7 pp 181 ff.
  39. ^ Kunze, Wolfgang (2004) "Technology Brewing and Malting" VLB Berlin, ISBN 3-921690-49-8 p.302
  40. ^ Ibid, p.351-352
  41. ^ All About Beer: Homebrewing-Secondary Fermentation
  1. "History of Beer," Foster's Group Home, Web, 22 Nov. 2009, [5]
  2. I. Hornsey, A History of Beer and Brewing (Rsc Paperbacks), Washington D.C.: Royal Society of Chemistry, 2004, Print.
  3. "History of Beer," Foster's Group Home, Web, 22 Nov. 2009, [6]
  4. "Ale University – History," Merchant du Vin. 2009, Web, 9 Nov. 2009, [7]
  5. "History of Beer," Foster's Group Home, Web, 22 Nov. 2009, [8]
  6. "History of Beer," Foster's Group Home, Web, 22 Nov. 2009, [9]
  7. "Beer (alcoholic beverage): History of brewing, Britannica Online Encyclopedia," Encyclopedia - Britannica Online Encyclopedia, 2009, Web. 10 Nov. 2009, [10]
  8. "Ale University – History," Merchant du Vin. 2009, Web, 9 Nov. 2009, [11]
  9. "History of Beer," Foster's Group Home, Web, 22 Nov. 2009, [12]
  10. I. Hornsey, A History of Beer and Brewing (Rsc Paperbacks), Washington D.C.: Royal Society of Chemistry, 2004, Print.

External links

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1911 encyclopedia

Up to date as of January 14, 2010

From LoveToKnow 1911

BREWING, in the modern acceptation of the term, a series of operations the object of which is to prepare an alcoholic beverage of a certain kind-to wit, beer-mainly from cereals (chiefly malted barley), hops and water. Although the art of preparing beer (q.v.) or ale is a very ancient one, there is very little information in the literature of the subject as to the apparatus and methods employed in early times. It seems fairly certain, however, that up to the 18th century these were of the most primitive kind. With regard to materials, we know that prior to the general introduction of the hop (see ALE) as a preservative and astringent, a number of other bitter and aromatic plants had been employed with this end in view. Thus L. Baker (The Brewing Industry) points out that the Cimbri used the Tamarix germanica, the Scandinavians the fruit of the sweet gale (Myrica gale), the Cauchi the fruit and the twigs of the chaste tree (Vitex agrius castus), and the Icelanders the yarrow (Achilloea millefolium). The preparation of beer on anything approaching to a manufacturing scale appears, until about the 12th or r3th century, to have been carried on in England chiefly in the monasteries; but as the brewers of London combined to form an association in the reign of Henry IV., and were granted a charter in 1445, it is evident that brewing as a special trade or industry must have developed with some rapidity. After the Reformation the ranks of the trade brewers were swelled by numbers of monks from the expropriated monasteries. Until the 18th century the professional brewers, or brewers for sale, as they are now called, brewed chiefly for the masses, the wealthier classes preparing their own beer, but it then became gradually apparent to the latter (owing no doubt to improved methods of brewing, and for others reasons) that it was more economical and less troublesome to have their beer brewed for them at a regular brewery. The usual charge was 30s. per barrel for bitter ale, and 8s. or so for small beer. This tendency to centralize brewing operations became more and more marked with each succeeding decade. Thus during 1895-1905 the number of private brewers declined from 17,041 to 9930. Of the private brewers still existing, about four-fifths were in the class exempted from beer duty, i.e. farmers occupying houses not exceeding £io annual value who brew for their labourers, and other persons occupying houses not exceeding £15 annual value. The private houses subject to both beer and licence duty produced less than 20,000 barrels annually. There are no official figures as to the number of "cottage brewers," that is, occupiers of dwellings not exceeding £8 annual value; but taking everything into consideration it is probable that more than 99% of the beer produced in the United Kingdom is brewed by public brewers (brewers for sale). The disappearance of the smaller public brewers or their absorption by the larger concerns has gone hand-in-hand with the gradual extinction of the private brewer. In the year 1894-1895 -8863 licences were issued to brewers for sale, and by 1904-1905 this number had been reduced to 5164. There are numerous reasons for these changes in the constitution of the brewing industry, chief among them being (a) the increasing difficulty, owing partly to lincensing legislation and its administration, and partly to the competition of the great breweries, of obtaining an adequate outlet for retail sale in the shape of licensed houses; and (b) the fact that brewing has continuously become a more scientific and specialized industry, requiring costly and complicated plant and expert manipulation. It is only by employing the most up-to-date machinery and expert knowledge that the modern brewer can hope to produce good beer in the short time which competition and high taxation, &c., have forced upon him. Under these conditions the small brewer tends to extinction, and the public are ultimately the gainers. The relatively nonalcoholic, lightly hopped and bright modern beers, which the small brewer has not the means of producing, are a great advance on the muddy, highly hopped and alcoholized beverages to which our ancestors were accustomed.

The brewing trade has reached vast proportions in the United Kingdom. The maximum production was 37,090, 9 86 barrels in 1900, and while there has been a steady decline since that year, the figures for 1905-1906-34,109,263 barrels-were in excess of those for any year preceding 1897. It is interesting in this connexion to note that the writer of the article on Brewing in the 9th edition of the Encyclopaedia Britannica was of the opinion that the brewing industry-which was then (1875) producing, roughly, 25,000,000 barrels-had attained its maximum development. In the year ending 30th September 1905 the beer duty received by the exchequer amounted to £13,156,053. The number of brewers for sale was 5180. Of these one firm, namely,, Messrs Guinness, owning the largest brewery in the world, brewed upwards of two million barrels, paying a sum of, roughly, one million sterling to the revenue. Three other firms brewed close on a million barrels or upwards. The quantity of malt used was 51,818,697 bushels; of unmalted corn, 125,671 bushels; of rice, flaked maize and similar materials, 1,348,558 cwt.; of sugar, 2.,746,615 cwt.; of hops, 62,360,817 lb; and of hop substitutes, 49,202 lb. The average specific gravity of the beer produced in 1905-1906 was 1053'24. The quantity of beer exported was 520,826; of beer imported, 57,194 barrels. It is curious to note that the figures for exports and imports had remained almost stationary for the last thirty years. By far the greater part of the beer brewed is consumed in England. Thus of the total quantity retained for consumption in 1905-1906, 28,590,563 barrels were consumed in England, 1,648,463 in Scotland, and 3,265,084 in Ireland. In 1871 it was calculated by Professor Leone Levi that the capital invested in the liquor trade in the United Kingdom was L117,000,000. In 1908 this figure might be safely doubled. A writer in the Brewers' Almanack for 1906 placed the capital invested in limited liability breweries alone at £185,000,000. If we allow for over-capitalization, it seems fairly safe to say that, prior to the introduction of the Licensing Bill of 1908, the market value of the breweries in the United Kingdom, together with their licensed property, was in the neighbourhood of £120,000,000, to which might be added another £20,000,000 for the value of licences not included in the above calculation; the total capital actually sunk in the whole liquor trade (including the wine and spirit industries and trades) being probably not far short of £250,000,000, and the number of persons directly engaged in or dependent on the liquor trade being under-estimated at 2,000,000. (For comparative production and consumption see Beer.) Taxation and Regulations.-The development of the brewing industry in England is intimately interwoven with the history of its taxation, and the regulations which have from time to time been formed for the safeguarding of the revenue. The first duty on beer in the United Kingdom was imposed in the reign of Charles II. (1660), namely 2s. 6d. per barrel on strong and 6d. per barrel on weak beer. This was gradually increased, amounting to 4s. 9d. on strong and Is. 3d. on weak beer in the last decade of the 17th century, and to 8s. to 10s. in the year 1800, at which rate it continued until the repeal of the beer duty in 1830. A duty on malt was first imposed in the reign of William III. (1697), and from that date until 1830 both beer duty and malt tax were charged. The rate at first was under 7d. per bushel, but this was increased up to 2s. 7d. prior to the first repeal of the beer duty (1830), and to 4s. 6d. after the repeal. In 1829 the joint beer and malt taxes amounted to no less than 13s. 8d. per barrel, or 42d. per gallon, as against 22d. at the present day. From 1856 until the abolition of the malt tax, the latter remained constant at a fraction under 2s. 81-d. A hop duty varying from id. to 22d. per pound was in existence between 1711 and 1862. One of the main reasons for the abolition of the hop duty was the fact that, owing to the uncertainty of the crop, the amount paid to the revenue was subject to wide fluctuations. Thus in 1855 the revenue from this source amounted to £728,183, in 1861 to only £149,700.

It was not until 1847 that the use of sugar in brewing was permitted, and in 1850 the first sugar tax, amounting to Is. 4d. per cwt., was imposed. It varied from this figure up to 6s. 6d. in 1854, and in 1874, when the general duty on sugar was repealed, it was raised to 11 s. 6d., at which rate it remained until 1880, when it was repealed simultaneously with the malt duty. In 1901 a general sugar tax of 4s. 2d. and under (according to the percentage of actual sugar contained) was imposed, but no drawback was allowed to brewers using sugar, and therefore-and this obtains at the present day-sugar used in brewing pays the general tax and also the beer duty.

By the Free Mash-Tun Act of 1880, the duty was taken off the malt and placed on the beer, or, more properly speaking, on the wort; maltsters' and brewers' licences were repealed, and in lieu thereof an annual licence duty of £r payable by every brewer for sale was imposed. The chief feature of this act was that, on and after the 1st of October 1880, a beer duty was imposed in lieu of the old malt tax, at the rate of 6s. 3d. per barrel of 36 gallons, at a specific gravity of 1.057, and the regulations for charging the duty were so framed as to leave the brewer practically unrestricted as to the description of malt or corn and sugar, or other description of saccharine substitutes (other than deleterious articles or drugs), which he might use in the manufacture or colouring of beer. This freedom in the choice of materials has continued down to the present time, except that the use of "saccharin" (a product derived from coal-tar) was prohibited in 1888, the reason being that this substance gives an apparent palate-fulness to beer equal to roughly 4° in excess of its real gravity, the revenue suffering thereby. In 1889 the duty on beer was increased by a reduction in the standard of gravity from 1.057 to 1.055, and in 1894 a further 6d. per barrel was added. The duty,, thus became 6s. 9d. per barrel, at a gravity of 1.055, which was further increased to 7s. 9d. per barrel by the war budget of 1900, at which figure it stood in 1909. (See also Liquor Laws.) Prior to 1896,x rice, flaked maize (see below), and other similar preparations had been classed as malt or corn in reference to their wort-producing powers, but after that date they were deemed sugar' in that regard. By the new act (1880) 42 lb weight of corn, or 28 lb weight of sugar, were to be deemed the equivalent of a bushel of malt, and a brewer was expected by one of the modes of charge to have brewed at least a barrel (36 gallons) of worts (less 4% allowed for wastage) at the standard gravity for every two bushels of malt (or its equivalents) used by him in brewing; but where, owing to lack of skill or inferior machinery, a brewer cannot obtain the standard quantity of wort from the standard equivalent of material, the charge is made not on the wort, but directly on the material. By the new act, licences at the annual duty of £1 on brewers for sale, and of 6s. (subsequently modified by 44 Vict. c. 12, and 48 and 49 Vict. c. 5, &c., to 4s.) or 9s., as the case might be, on any other brewers, were required. The regulations dealing with the mashing operations are very stringent. Twenty-four hours at least before mashing the brewer must enter in his brewing book (provided by the Inland Revenue) the day and hour for commencing to mash malt, corn, &c., or to dissolve sugar; and the date of making such entry; and also, two hours at least before the notice hour for mashing, the quantity of malt, corn, &c., and sugar to be used, and the day and hour when all the worts will be drawn off the grains in the mash-tun. The worts of each brewing much be collected within twelve hours of the commencement of the collection, and the brewer must within a given time enter in his book the quantity and gravity of the worts before fermentation, the number and name of the vessel, and the date of the entry. The worts must remain in the same vessel undisturbed for twelve hours after being collected, unless previously taken account of by the officer. There are other regulations, e.g. those prohibiting the mixing of worts of different brewings unless account has been taken of each separately, the alteration of the size or shape of any gauged vessel without notice, and so on.

Taxation of Beer in Foreign Countries.-The following table shows the nature of the tax and the amount of the same calculated to English barrels.

Materials Used In Brewing.-These are water, malt (q.v.), hops (q.v.), various substitutes for the two latter, and preservatives.

Water.-A satisfactory supply of water-which, it may here be mentioned, is always called liquor in the brewery-is a matter of great importance to the brewer. Certain waters, for instance, those contaminated to any extent with organic matter, cannot be used at all in brewing, as they give rise to unsatisfactory fermentation, cloudiness and abnormal flavour. Others again, although suited to the production of one type of beer, are quite unfit for the brewing of another. For black beers a soft water is a desideratum, for ales of the Burton type a hard water is a necessity. For the brewing of mild ales, again, a water contain 1 They were classified at 281b in 1896, but since 1897 the standard has been at the rate of 32 lb to the bushel.

ing a certain proportion of chlorides is required. The presence or absence of certain mineral substances as such in the finished beer is not, apparently, a matter of any moment as regards flavour or appearance, but the importance of the role played by these substances in the brewing process is due to the influence which they exert on the solvent action of the water on the various constituents of the malt, and possibly of the hops. The excellent quality of the Burton ales was long ago surmised to be due mainly to the well water obtainable in that town. On analysing Burton water it was found to contain a considerable quantity of calcium sulphate-gypsum-and of other calcium and magnesium salts, and it is now a well-known fact that good bitter ales cannot be brewed except with waters containing these substances in sufficient quantities. Similarly, good mild ale waters should contain a certain quantity of sodium chloride, and waters for stout very little mineral matter, excepting perhaps the carbonates of the alkaline earths, which are precipitated on boiling.

The following analyses (from W. J. Sykes, The Principles and Practice of Brewing) are fairly illustrative of typical brewing waters.

Burton Water (Pale Ale).

Sodium Chloride .

Potassium Sulphate

Sodium Nitrate .

Calcium Sulphate .

Calcium Carbonate .

Magnesium Carbonate

Silica and Alumina .

Dublin Water (Stout).

Sodium Chloride. .

Calcium Sulphate .

Calcium Carbonate .

Magnesium Carbonate

Iron Oxide and Alumina

Silica

Mild Ale Water.

Sodium Chloride .

Calcium Chloride .

Calcium Sulphate .

Calcium Carbonate .

Iron Oxide and Alumina

Silica .

Grains per Gallon.

3.90

1.59

1'97

77.87

7.62

21.31

0 98

1.83

4'45

14.21

0.90

0.24

0.26

35'14

3'88

6.23

4.01

0.24

0.22

Our knowledge of the essential chemical constituents of brewing waters enables brewers in many cases to treat an unsatisfactory supply artificially in such a manner as to modify its character in a favourable sense. Thus, if a soft water only is to hand, and it is desired to brew a bitter ale, all that is necessary is to add a sufficiency of gypsum, magnesium sulphate and calcium chloride. If it is desired to convert a soft water lacking in chlorides into a satisfactory mild ale liquor, the addition of 30-40 grains of sodium chloride will be necessary. On the other hand, to convert a hard water into a soft supply is scarcely feasible for brewing purposes. To the substances used for treating brewing liquors already mentioned we may add kainite, a naturally deposited composite salt containing 'potassium and magnesium sulphates and magnesium chloride.

Malt Substitutes.-Prior to the repeal of the Malt Acts, the only substitute for malt allowed in the United Kingdom was sugar. The quantity of the latter employed was 295,865 cwt. in 1870, 1,136,434 cwt. in 1880, and 2,746,615 cwt. in 1905; that is to say, that the quantity used had been practically trebled during the last twenty-five years, although the quantity of malt employed had not materially increased. At the same time other substitutes, such as unmalted corn and preparations of rice and maize, had come into favour, the quantity of these substances used being in 1905 125,671 bushels of unmalted corn and 1,348,558 cwt. of rice, maize, &c.

The following statistics with regard to the use of malt substitutes in the United Kingdom are not without interest.

Country.

Y

Nature of Tax.

Amount per English Barrel

(round numbers).

United States. .

Beer Tax

5s. 9d.

Germany-

N. German Customs Union

Malt Tax

is. 6d.

Bavaria

Malt Tax

3s. 5d. to 4s. 8d., according to

quantity produced

Belgiu

Malt Tax

2s. 9d.

France. ... .

On Wort

4s. id.

Holland. ... .

On cubic contents of

Mash-Tun or on Malt

About Ts. 9d. to 3s. 3d.,

according to quality

Austro-Hungarian Empire .

On Wort

6s. 8d.

Russia .

Malt Tax

5s. to 6s. 8d.

Year.

Quantities of

Malt and Corn

used in Brewing.

Quantities of Sugar,

Rice, Maize, &c.

used in Brewing.

Percentage of

Substitutes to

Total Material.

Bushels.

Bushels.

18 7 8

59,388,905

3,825,148

6 05

1883

51,331,4511

4,503,6802

8 06

18 9 0

55,359,964'

7,904,708'

12.48

18 95

53,731,177

10,754,510

16.66

1905

51,942,368

15,706,413

23.22

The causes which have led to the largely increased use of substitutes in the United Kingdom are of a somewhat complex nature. In the first place, it was not until the malt tax was repealed that the brewer was able to avail himself of the surplus diastatic energy present in malt, for the purpose of transforming starch (other than that in malted grain) into sugar. The diastatic enzyme or ferment (see below, under Mashing) of malted barley is present in that material in great excess, and a part of this surplus energy may be usefully employed in converting the starch of unmalted grain into sugar. The brewer has found also that brewing operations are simplified and accelerated by the use of a certain proportion of substitutes, and that he is thereby enabled appreciably to increase his turn-over, i.e. he can make more beer in a given time from the same plant. Certain classes of substitutes, too, are somewhat cheaper than malt, and in view of the keenness of modern competition it is not to be wondered at that the brewer should resort to every legitimate means at his disposal to keep down costs. It has been contended, and apparently with much reason, that if the use of substitutes were prohibited this would not lead to an increased use of domestic barley, inasmuch as the supply of home barley suitable for malting purposes is of a limited nature. A return to the policy of "malt and hops only" would therefore lead to an increased use of foreign barley, and to a diminution in the demand for home barley, inasmuch as sugar and prepared cereals, containing as they do less nitrogen, &c. than even the well-cured, sun-dried foreign barleys, are better diluents than the latter. At the same time, it is an undoubted fact that an excessive use of substitutes leads to the production of beer of poor quality. The better class of brewer rarely uses more than 1 520%, knowing that beyond that point the loss of flavour and quality will in the long run become a more serious item than any increased profits which he might temporarily gain.

With regard to the nature of the substitutes or adjuncts for barley malt more generally employed, raw grain (unmalted barley, wheat, rice, maize, &c.) is not used extensively in Great Britain, but in America brewers employ as much as 50%, and even more, of maize, rice or similar materials. The maize and rice preparations mostly used in England are practically starch pure and simple, substantially the whole of the oil, water, and other subsidiary constituents of the grain being removed. The germ of maize contains a considerable proportion of an oil of somewhat unpleasant flavour, which has to be eliminated before the material is fit for use in the mash-tun. After degerming, the maize is unhusked, wetted, submitted to a temperature sufficient to rupture the starch cells, dried, and finally rolled out in a flaky condition. Rice is similarly treated.

The sugars used are chiefly cane sugar, glucose and invert sugar - the latter commonly known as "saccharum." Cane sugar is mostly used for the preparation of heavy mild ales and stouts, as it gives a peculiarly sweet and full flavour to the beer, to which, no doubt, the popularity of this class of beverage is largely due. Invert sugar is prepared by the action either of acid or of yeast on cane sugar. The chemical equation representing the conversion (or inversion) of cane sugar is: - C12H22011 + H20 = C6H1206 C6H,206 cane sugar water glucose fructose invert sugar Invert sugar is so called because the mixture of glucose and fructose which forms the "invert" is laevo-rotatory, whereas I Inclusive of rice and maize. Exclusive of rice and maize.

cane sugar is dextro-rotatory to the plane of polarized light. The preparation of invert sugar by the acid process consists in treating the cane sugar in solution with a little mineral acid, removing the excess of the latter by means of chalk, and concentrating to a thick syrup. The yeast process (Tompson's), which makes use of the inverting power of one of the enzymes (invertase) contained in ordinary yeast, is interesting. The cane sugar solution is pitched with yeast at about 55° C., and at this comparatively high temperature the inversion proceeds rapidly, and fermentation is practically impossible. When this operation is completed, the whole liquid (including the yeast) is run into the boiling contents of the copper. This method is more suited to the preparation of invert in the brewery itself than the acid process, which is almost exclusively used in special sugar works. Glucose, which is one of the constituents of invert sugar, is largely used by itself in brewing. It is, however, never prepared from invert sugar for this purpose, but directly from starch by means of acid. By the action of dilute boiling acid on starch the latter is rapidly converted first into a mixture of dextrine and maltose and then into glucose. The proportions of glucose, dextrine and maltose present in a commercial glucose depend very much on the duration of the boiling, the strength of the acid, and the extent of the pressure at which the starch is converted. In England the materials from which glucose is manufactured are generally sago, rice and purified maize. In Germany potatoes form the most common raw material, and in America purified Indian corn is ordinarily employed.

Hop substitutes, as a rule, are very little used. They mostly consist of quassia, gentian and camomile, and these substitutes are quite harmless per se, but impart an unpleasantly rough and bitter taste to the beer.

Preservatives

These are generally, in fact almost universally, employed nowadays for draught ales; to a smaller extent for stock ales. The light beers in vogue to-day are less alcoholic, more lightly hopped, and more quickly brewed than the beers of the last generation, and in this respect are somewhat less stable and more likely to deteriorate than the latter were. The preservative in part replaces the alcohol and the hop extract, and shortens the brewing time. The preservatives mostly used are the bisulphites of lime and potash, and these, when employed in small quantities, are generally held to be harmless.


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Wikibooks

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From Wikibooks, the open-content textbooks collection

The text in its current form is incomplete.

A glass of Weizenbier.

Beer making has a long and varied history through out the world. From individuals making a couple of cases at home in the kitchen to large industrial sites that produce hundreds of cases per hour. That you want to home brew says that you have tried a couple of different beers and thought you would like to taste something different, or that you could do better. Don't worry! Homebrewing isn't that hard. It does require patience and some attention to detail. But don't stress out. As a sage once put it: Relax, Don't worry, have a homebrew!
Below you will find a collection of articles discussing the different aspects to homebrewing. Feel free to look through them.

Thanks!

Foreword to the Student

Welcome to the world of home beer brewing! This wikibook aims to help you, the student, become a well rounded and versed master home brewer. It is recommended that you use this book as part of a class led by an experienced instructor, who can lead you through the book and assist you in practical application of the information contained therein. However, determined students will certainly be able to use this material to be their own instructor, and in such case, you should probably read the instructor foreword. Beer brewing is an exciting and mind opening process, and will allow you to refine your tastes for beer by better understanding the hows, the whys, and the history of beer production.

Foreword to the Instructor

As an instructor, you are carrying on an ancient tradition. It is imperative that you impart your charge with as much appreciation and as much enthusiasm for beer making as you should have. This book aims to be a complete discourse on the entire beer making process, and to avoid repeating identical material it has been organized in a "grain to stein" fashion. Unfortunately, this organization will prove to push too much information too soon to entice a beginner and get him on the road to making a quality beer.

So, for the instructor (and students instructing themselves), here is a recommended path through this book: Cleaning/Sanitization, Procedures, Equipment, Boiling, Cooling, Fermentation, Bottling/Kegging, Ingredients, Mashing, Lautering, Cultivation, Malting. It is assumed that this path will be accompanied with relevant lectures and excercises, to reinforce the material and affect a better understanding. For the self instructing brewer, we recommend that you follow this path, reading at least to the point of fermentation before performing your first "brew-day," while paying attention to procedures relating to extract brewing. Once you have pitched yeast, you will have at least 2 weeks to read the bottling/kegging section, and decide how you intend to finish your beer. Natural bottle carbonation is the least expensive way, but it is also the easiest with which to make mistakes resulting in sub-standard beer (or exploding bottles, which is fun). A kegging system is quite an investment, especially for first timers who may find that homebrewing is not the hobby for them, but it is the most straight forward method, often producing a more consistent quality beer.

Once the self instructing student has become comfortable with the simplified process using extract, we recommend he continue learning about the rest of the process and at least try to produce an "all-grain" brew. Little additional equipment required, while the resulting beer can be several orders of quality and freshness better than an extract brew from comparable initial ingredients, not to mention that per-batch costs can even go down.

Table of Contents

  1. Brewing Overview
  2. Ingredients
  3. Equipment
  4. Procedures
    1. Cleaning/Sanitization
    2. Milling
    3. Mashing
    4. Lautering
    5. Boiling
    6. Cooling
    7. Fermentation
    8. Bottling/Kegging
  5. Recipes
  6. References
  7. Authors







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