Reinheitsgebot

From Wikipedia, the free encyclopedia

Crown cap "500 Years of Reinheitsgebot in Munich (since 1487)" on a bottle of German beer

The Reinheitsgebot (German pronunciation: [ʁaɪnhaɪtsɡəboːt] ( listen), literally "purity order"), sometimes called the "German Beer Purity Law" or the "Bavarian Purity Law" in English, is a regulation concerning the production of beer in Germany. In the original text, the only ingredients that could be used in the production of beer were water, barley, and hops. The law has since been repealed but many German beers, for marketing purposes, continue to declare that they abide by the rule, to reassure customers that only the three permissible ingredients are used.

The law originated in the city of Ingolstadt in the duchy of Bavaria on 23 April 1516, although first put forward in 1487,^[1] concerning standards for the sale and composition of beer.

Contents [hide] 1 The text 2 History 3 Criticism 4 References 5 Further reading 6 External links

The text

In the original text, the only ingredients that could be used in the production of beer were water, barley, and hops. The law also set the price of beer at 1-2 Pfennig per Maß. The Reinheitsgebot is no longer part of German law: it has been replaced by the Provisional German Beer Law (Vorläufiges Deutsches Biergesetz (Provisional German Beer-law of 1993)), which allows constituent components prohibited in the Reinheitsgebot, such as wheat malt and cane sugar, but which no longer allows unmalted barley.

Note that no yeast was mentioned in the original text. It was not until the 1800s that Louis Pasteur discovered the role of microorganisms in the process of fermentation; therefore, yeast was not known to be an ingredient of beer. Brewers generally took some sediment from the previous fermentation and added it to the next, the sediment generally containing the necessary organisms to perform fermentation. If none were available, they would set up a number of vats, relying on natural yeast to inoculate the brew.

Hops are added to beer to impart flavours but also act as a preservative, and their mention in the Reinheitsgebot meant to prevent inferior methods of preserving beer that had been used before the introduction of hops. Medieval brewers had used many problematic ingredients to preserve beers, including, for example, soot and fly agaric mushrooms. More commonly, other herbs had been used, such as stinging nettle and henbane.

The penalty for making impure beer was also set in the Reinheitsgebot: a brewer using other ingredients for his beer could have questionable barrels confiscated with no compensation.

German breweries are very proud of the Reinheitsgebot, and many (even brewers of wheat beer^[2]) claim to still abide by it.

History

Reinheitsgebot was introduced in part to prevent price competition with bakers for wheat and rye. The restriction of grains to barley was meant to ensure the availability of sufficient amounts of affordable bread, as the more valuable wheat and rye were reserved for use by bakers. Today many Bavarian beers are again brewed using wheat and are thus no longer compliant with the Reinheitsgebot.

The Reinheitsgebot formed the basis of legislation that spread slowly throughout Bavaria and Germany. Bavaria insisted on its application throughout Germany as a precondition of German unification in 1871, to prevent competition from beers brewed elsewhere with a wider range of ingredients. The move encountered strong resistance from brewers outside Bavaria. By restricting the allowable ingredients, it led to the extinction of many brewing traditions and local beer specialties, such as North German spiced beer and cherry beer, and led to the domination of the German beer market by pilsener style beers. Only a few regional beer varieties, such as Kölner Kölsch or Düsseldorfer Altbier, survived its implementation.

Regulations similar to those of the Reinheitsgebot were incorporated into various guild regulations and local laws all over Germany, and in 1952, they were incorporated into the West German Biersteuergesetz (Beer Taxation Law) and vorläufiges Biergesetz (Provisional Beer Law). Many brewers objected to the law at the time, disagreeing more with the amount of the tax than the ingredient requirements. The law initially applied only to bottom-fermented ("lager") beers, but brewers of other types of beer soon accepted the law as well.

In May 1987, a European Court of Justice ruling led to the Reinheitsgebot being lifted, allowing ingredients beyond what is listed in the Biergesetz; this meant that anything allowed in other foods was thus also allowed in beer. The ingredient requirements have since been moved from the Biersteuergesetz into the regular food additives laws, though beer brewed according to the Reinheitsgebot receive special treatment as a protected, "traditional" food.

The vast majority of German breweries continue to comply with the Biergesetz, often claiming compliance with the Reinheitsgebot even when it is patently incorrect (for example, for wheat beers, which were prohibited by the Reinheitsgebot), using this compliance as a valuable marketing tool.

Until superseded by a change in EU law, the Reinheitsgebot was also enforced in Greece from the early 19th century due to a law by the first Greek king, Otto (originally a Bavarian prince) that had remained in effect for hundreds of years.

Criticism

When it was in effect, the law drew criticism from foreign brewers as a form of protectionism (a trade restriction) that allowed West Germany to prohibit non-compliant imports, even beers from states such as Belgium and the United Kingdom with their own long brewing traditions.

References

1. ^ Bolt, Rodney (1999). Bavaria. Old Saybrook, CT: Globe Pequot Press. p. 37. ISBN 1860119166.
2. ^ "Brewed in full accordance with the Bavarian 'Purity Law' of 1516" appears on the label of Franziskaner Hefe-Weisse, a type of wheat Beer

Further reading

• Dornbusch, Horst D. (1997). Prost!: The Story of German Beer. Boulder, CO: Siris Books. ISBN 0937381551.

External links

• English translation of the 'Reinheitsgebot'
• German Beer Purity Order, 1516

Retrieved from "http://en.wikipedia.org/wiki/Reinheitsgebot"

Categories: Alcohol law | Bavaria | German beer culture | German law | Alcohol in Germany

Adjuncts

From Wikipedia, the free encyclopedia

Wheat - adjunct or ingredient?

Adjuncts are unmalted grains (such as corn, rice, rye, oats, barley, and wheat^[1]) used in brewing beer which supplement the main mash ingredients (such as malted barley), often with the intention of cutting costs, but sometimes to create an additional feature, such as better foam retention.

Contents [hide] 1 Adjunct definition 2 Adjunct types 3 Starch adjuncts 3.1 Rice 3.2 Maize/Corn 3.3 Wheat 3.4 Rye 3.5 Oats 4 Sugar adjuncts 5 Flavourings 5.1 Spices 5.2 Other flavourings 6 Fruit or vegetable beer 6.1 Fruit flavouring and adjuncts 6.2 Vegetable flavouring and adjunct 7 See also 8 References 9 External links

Adjunct definition

Ingredients which are standard for certain beers, such as wheat in a wheat beer, may be termed adjuncts when used in beers which could be made without them — such as adding wheat to a pale ale for the purpose of creating a lasting head. The sense here is that the ingredient is additional and strictly unnecessary, though it may be beneficial and attractive. Under the Bavarian Reinheitsgebot purity law it would be considered that an adjunct is any beer ingredient other than water, barley and hops; this, however, is an extreme view and is not standard.

The term adjunct is often used to refer to corn and rice, the two adjuncts commonly used by pale lager brewing companies as substitutes for barley malt. This use of ingredients as substitutes for the main starch source, usually to lower the cost of production, is where the term adjunct is most often used.

Adjunct types

Adjuncts can be broadly separated into solids and liquid syrups. Solid adjuncts are ingredients such as cereals, flakes, grits and flours which must be added to the mash tun in order to convert the starch into simple sugars which the yeast can utilise during fermentation. Some cereals have a higher gelatinisation temperature than the standard mashing temperatures and must be cooked in a cereal cooker to gelatinise the starch before adding to the mash.

Liquid syrups, on the other hand, are designed to be added directly to the kettle and therefore can be used to reduce loading on the mash and lauter tun and effectively increase the brewhouse capacity.

Other benefits of using adjuncts include reducing cost, improving consistency, diluting wort nitrogen (thereby improving shelf life) and reducing colour (or increasing colour with roasted cereals and caramels.)

Starch adjuncts

Rice

Rice is sometimes used in the production of pale lagers, most notably Anheuser-Busch's Budweiser. Anheuser-Busch is the largest North American buyer of U.S. rice ^[2]. Rice may be used to lighten the body and the mouthfeel, or increase alcohol content, or add a little sweetness. Because rice is cheaper than barley, it can be used as a cost-saving measure.

Maize/Corn

Corn is commonly used in the production of American-style pale lagers, particularly malt liquor. Corn is generally used in brewing as corn syrup, and as such is highly fermentable. Like rice, corn is cheaper than barley, so it is used as a cost-saving measure.

Wheat

Wheat is used in German and American wheat beers, in lambic and other Belgian ales, and in English ales. Wheat lightens the body, improves head retention, and provides a tart flavour. Wheat beers are often served with fruit syrups and/or slices of lemon in the US and Germany.

Rye

Rye is used in roggenbiers from Germany and in rye beers from America. Rye is notoriously difficult to brew with, so most rye beers only include a small amount of rye.^{[citation needed]} Rye provides a spicy flavour to beer and dramatically increases head formation.

Oats

Oats are used in oatmeal stouts. They provide a silky mouthfeel and a mild flavour.

Sugar adjuncts

Technically these are not true adjuncts but additives as they do not utilise the enzymes from the malt to convert starch to sugars.^{[citation needed]} Sweeteners such as maple syrup, honey, and molasses are common. In honey beer the honey supplies only a portion of the sugars converted during fermentation and is used primarily for flavour. Candy sugar is a common ingredient in strong Belgian ales, where it increases the beer's strength while keeping the body fairly light; dark varieties of candy sugar also affect the colour and flavour of the beer.

Sugars added for bottle conditioning are not generally considered adjuncts.

Flavorings

Spices

A number of traditional beer styles are brewed with spices. For example, Belgian witbier is brewed with coriander, Finnish sahti is brewed with juniper berries, and traditional beers in Britain are brewed with honey and spices. Also, some strong winter beers are flavoured with nutmeg and/or cinnamon, while ginger is a popular flavouring for a range of beers. Many commercially available pumpkin ales are made with pumpkin pie spices without any actual pumpkin.

Spices may be added to the wort during the boil or spices or spice extract may be added at any time during fermentation depending on desired results.

Spices used in brewing include:

• Allspice
• Anise
• Cinnamon
• Clove
• Coriander
• Ginger
• Hot pepper
• Juniper berries or boughs
• Licorice
• Nutmeg
• Orange or Lemon peel
• Spruce needles or twigs (see spruce beer)
• Yarrow

Other flavourings

Other, less common flavourings include chocolate, coffee, milk, chile peppers and even oysters.

Magic Hat #9 fruit beer in a mug.

Fruit or vegetable beer

A fruit beer or a vegetable beer is a beer brewed with a fruit or vegetable adjunct or flavouring.

Fruit flavouring and adjuncts

Fruits have been used as a beer adjunct or flavouring for centuries, especially with Belgian lambic styles. Cherry, raspberry, and peach are a common addition to this style of beer. Modern breweries may add only flavoured extracts to the finished product, rather than actually fermenting the fruit.

One of the most prominent brewers of fruit beer is Yanjing Beer, one of the largest Chinese breweries, which widely markets Pineapple and Lemon beer. New Glarus Brewing Company, of New Glarus, Wisconsin, produces Raspberry Tart, a framboise made with raspberries, wheat and year old Hallertau hops, and fermented in large oak vats. Magic Hat Brewing Company of Vermont brews '#9', quite popular in the northeastern U.S. and is a 'not-quite-pale ale' flavoured with apricots. RJ Rockers Brewing Company of South Carolina released Son of a Peach Wheat Ale in 2009 which is made with real peaches added during the fermentation process ^[3]. Früli is a fruit beer made from 70% wheat beer and 30% fruit juice.

Vegetable flavouring and adjunct

Anheuser-Busch brews Tequiza, a beer flavoured with tequila from blue agave nectar. Desperados is a tequila-flavoured beer popular among German and French youth.

Pumpkin-flavoured beers are brewed seasonally in the autumn in North America. An example, Pumpkin Ale, is produced by Coors Brewing Company's Blue Moon brand.

Chile pepper is used to flavour pale lagers. One of the most popular American chile beers is produced by Eske's (aka Sangre de Cristo Brewing) in Taos, New Mexico. Eske's "Taos Green Chile Beer" is made with New Mexico roasted green chiles. Black Mountain Brewing Company in Cave Creek, Arizona, brews "Cave Creek Chili Beer", the only internationally marketed chile beer.

See also

• Beer styles
• Brewing
• Gruit

[edit] References

1. ^ Beer Adjuncts: The Brewers' Handbook
2. ^ http://www.anheuser-busch.com/overview/BudIngredients.htm 1
3. ^ Spartanburg Herald Journal, "SC fruit inspires local brewery's new creation", April 8, 2009

[edit] External links

• Beer-brewing.Com

Retrieved from "http://en.wikipedia.org/wiki/Adjuncts"

Categories: Brewing

Hidden categories: Articles needing additional references from June 2009 | All articles with unsourced statements | Articles with unsourced statements from May 2009 | Articles with unsourced statements from December 2008

Mashing

From Wikipedia, the free encyclopedia

Interior view of a mash tun in a Scotch whisky distillery, showing the stirring mechanism.

In brewing and distilling, mashing is the process of combining a mix of milled grain (typically malted barley with supplementary grains such as corn, sorghum, rye or wheat), known as the "grain bill", and water, known as "liquor", and heating this mixture with pauses at certain temperatures (notably 45°C, 62°C and 73°C ^[1][2][3]) to allow the enzymes in the malt to break down the starch in the grain into sugars, typically maltose to create a malty liquid called wort.

Mashing takes place in a "mash tun" - an insulated brewing vessel with a false bottom. The end product of mashing is called a "mash".

Contents [hide] 1 Infusion mashing 2 Decoction mashing 3 Mash tun 4 Ingredient selection 4.1 Nitrogen content 4.2 Diastatic power 4.3 Color 4.4 Modification 4.5 Conversion 5 Grain milling 6 Mashing-in 7 Enzymatic rests 7.1 β-glucanase rest 7.2 Protease rest 7.3 Amylase rests 7.4 Decoction "rests" 8 Mash-out 9 See also 10 External links 11 References

Infusion mashing

Most breweries use infusion mashing, in which the mash is heated directly to go from rest temperature to rest temperature. Some infusion mashes achieve temperature changes by adding hot water, and there are also breweries that do single-step infusion, performing only one rest before lautering.

Decoction mashing

Decoction mashing is where a proportion of the grains are boiled and then returned to the mash, raising the temperature. The boiling extracts more starch from the grain by breaking down the cell walls of the grain.

This can be classified into one-, two-, and three-step decoctions, depending on how many times part of the mash is drawn off to be boiled.^[4]

Mash tun

In large breweries, in which optimal utilization of the brewery equipment is economically necessary, there is at least one dedicated vessel for mashing. In decoction processes there must be at least two. The vessel has a good stirring mechanism to keep the temperature of the mash uniform, and a heating device which is efficient, but will not scorch the malt (often steam), and should be insulated to maintain rest temperatures for up to one hour. A spray ball for clean-in-place (CIP) operation should also be included for periodical deep cleaning. Sanitation is not a major concern before wort boiling, so a rinse-down should be all that is necessary between batches.

Smaller breweries will often use a boil kettle or a lauter tun for mashing. The latter case either limits the brewer to single-step infusion mashing, or leaves the brewer with a lauter tun which is not completely appropriate for the lautering process.

Ingredient selection

See also: Mash ingredients

Each particular ingredient has its own flavor which contributes to the final character of the beverage. In addition, different ingredients carry other characteristics, not directly relating to the flavor, which may dictate some of the choices made in brewing: nitrogen content, diastatic power, color, modification, and conversion.

Nitrogen content

The nitrogen content of a grain refers to the mass fraction of the grain which is made up of protein, and is usually expressed as a percentage; this fraction is further refined by distinguishing what fraction of the protein is water-soluble, also usually expressed as a percentage; 40% is typical for most beermaking grains. Generally, brewers favor lower-nitrogen grains, while distillers favor high-nitrogen grains.

In most beermaking, an average nitrogen content in the grains of at most 10% is sought; higher protein content, especially the presence of high-mass proteins, causes "chill haze", a cloudy visual quality to the beer. However, this is mostly a cosmetic desire dating from the mass production of glassware for presenting serving beverages; traditional styles such as sahti, saison, and bière de garde, as well as several Belgian styles, make no special effort to create a clear product. The quantity of high-mass proteins can be reduced during the mash by making use of a protease rest.

In Britain, preferred brewers' grains are often obtained from winter harvests and grown in low-nitrogen soil; in central Europe, no special changes are made for the grain-growing conditions and multi-step decoction mashing is favored instead.

Distillers, by contrast, are not as constrained by the amount of protein in their mash as the non-volatile nature of proteins means that none will be included in the final distilled product. Therefore, distillers seek out higher-nitrogen grains in order to ensure a more efficiently-made product; higher-protein grains generally have more diastatic power.

Diastatic power

The diastatic power (DP), also called the "diastatic activity" or "enzymatic power", of a grain generally refers only to malts, grains which have begun to germinate; the act of germination includes the production of a number of enzymes such as amylase which convert starch into sugar; thereby, sugars can be extracted from the barley's own starches simply by soaking the grain in water at a controlled temperature: this is mashing. Other enzymes break long proteins into short ones and accomplish other important tasks.

In general, the hotter a grain is kilned, the less its diastatic activity; consequently, only lightly-colored grains can be used as base malts, with Munich malt being the darkest base malt generally available.

Diastatic activity can also be provided by diastatic malt extract or by inclusion of separately-prepared brewing enzymes.

Diastatic power for a grain is measured in degrees Lintner (°Lintner or °L, although the latter can conflict with the symbol °L for Lovibond color); or in Europe by Windisch-Kolbach units (°WK). The two measures are related by

.

A malt with enough power to self-convert has a diastatic power near 35 °Lintner (94 °WK); the most active, so-called "hottest" malts currently available, American six-row pale barley malts, have a diastatic power of up to 160 °Lintner (544 °WK).

Color

In brewing, the color of a grain or product is evaluated by the Standard Reference Method (SRM), Lovibond (°L), American Society of Brewing Chemists (ASBC) or European Brewery Convention (EBC) standards. While SRM and ASBC originate in North America and EBC in Europe, all three systems can be found in use throughout the world; degrees Lovibond has fallen out of industry use but has remained in use in homebrewing circles as the easiest to implement without a spectrophotometer. The darkness of grains range from as light as 3 SRM/5 EBC for Pilsener malt to as dark as 70 SRM/1600 EBC for black malt and roasted barley.

Modification

The quality of starches in a grain is variable with the strain of grain used and its growing conditions. "Modification" refers specifically to the extent to which starch molecules in the grain consist of simple chains of sugar molecules versus branched chains; a fully modified grain contains only simple-chain starch molecules. A grain that is not fully modified requires mashing in multiple steps rather than at simply one temperature as the starches must be de-branched before amylase can work on them.

Conversion

Conversion is the extent to which starches in the grain have been enzymatically broken down into sugars. A caramel or crystal malt is fully converted before it goes into the mash; most malted grains have little conversion; unmalted grains, meanwhile, have little or no conversion. Unconverted starch becomes sugar during the last steps of mashing, through the action of alpha and beta amylases.

Grain milling

The grain used for making beer must first be milled. Milling increases the surface area of the grain, making the starch more accessible, and separates the seed from the husk. Care must be taken when milling to ensure that the starch reserves are sufficiently milled without damaging the husk and providing coarse enough grits that a good filter bed can be formed during lautering.

Grains are typically dry milled. Dry mills come in four varieties: two-, four-, five-, and six-roller mills. Hammer mills, which produce a very fine mash, are often used when mash filters are going to be employed in the Lautering process because the grain does not have to form its own filterbed. In modern plants, the grain is often conditioned with water before it is milled to make the husk more pliable, thus reducing breakage and improving lauter speed.

Two-roller mills Two-roller mills are the simplest variety, in which the grain is crushed between two rollers before it continues on to the mash tun. The spacing between these two rollers can be adjusted by the operator. Thinner spacing usually leads to better extraction, but breaks more husk and leads to a longer lauter.

Four-roller mills Four-roller mills have two sets of rollers. The grain first goes through rollers with a rather wide gap, which separates the seed from the husk without much damage to the husk, but leaves large grits. Flour is sieved out of the cracked grain, and then the coarse grist and husks are sent through the second set of rollers, which further crush the grist without damaging the crusts. There are three-roller mills, in which one of the rollers is used twice, but they are not recognized by the German brewing industry.

Five- and Six-roller mills Six-roller mills have three sets of rollers. The first roller crushes the whole kernel, and its output is divided three ways: flour immediately is sent out the mill, grits without a husk proceed to the last roller, and husk, possibly still containing parts of the seed, go to the second set of rollers. From the second roller flour is directly output, as are husks and any possible seed still in them, and the husk-free grits are channeled into the last roller. Five-rolle basically six-roller mills in which one of the rollers performs double-duty.

Mashing-in

Mixing of the strike water, water used for mashing in, and milled grist must be done in a such a way as to minimize clumping and oxygen uptake. Traditionally this was done by first adding water to the mash vessel, and then introducing the grist from the top of the vessel in a thin stream. This unfortunately led to a lot of oxygen absorption, and loss of flour dust to the surrounding air. A premasher, which mixes the grist with mash-in temperature water while it is still in the delivery tube, reduces oxygen uptake and prevents dust from being lost.

Mashing in is typically done between 35 °C and 45 °C (95 °F and 113 °F), but for single-step infusion mashes mashing in must be done between 62 °C and 67 °C (143.6 °F and 152.6 °F) for amylases to break down the grain's starch into sugars. The weight-to-weight ratio of strike water and grain varies from 1:2 for dark beers in single-step infusions to 1:4 or even 1:5, ratios more suitable for light-colored beers and decoction mashing, where much mash water is boiled off.

Enzymatic rests

Optimal rest temperatures for major mashing enzymes

Temp °C	Temp °F	Enzyme	Breaks down
40 °C	104.0 °F	β-Glucanase	β-Glucan
50 °C	122.0 °F	Protease	Protein
62 °C	143.6 °F	β-Amylase	Starch
72 °C	161.6 °F	α-Amylase	Starch

In step-infusion and decoction mashing, the mash is heated to different temperatures, at which specific enzymes work optimally. The table at right shows the optimal temperature for the enzymes brewers most pay attention to, and what material those enzymes break down. There is some contention in the brewing industry as to just what the optimal temperature is for these enzymes, as it is often very dependent on the pH of the mash, and its thickness. A thicker mash acts as a buffer for the enzymes. Once a step is passed, the enzymes active in that step are denatured, and become permanently inactive. The time between rests is preferably as short as possible, but if the temperature is raised more than 1 °C per minute, enzymes may be prematurely denatured in the transition layer near heating elements.

β-glucanase rest

β-glucan is a chain of the beta isomer of glucose molecules, and found mainly in the cell walls of plants, and in this context is also known as cellulose. A β-glucanase rest done at 40 °C is practiced in order to break down cell walls and make starches more available, thus raising the extraction efficiency. Should the brewer let this rest go on too long, it is possible that a large amount of β-glucan will dissolve into the mash, which can lead to a stuck mash on brew day, and cause filtration problems later in beer production.

Protease rest

Protein degradation via a proteolytic rest plays many roles: production of free-amino nitrogen (FAN) for yeast nutrition, freeing of small proteins from larger proteins for foam stability in the finished product, and reduction of haze-causing proteins for easier filtration and increased beer clarity. In all-malt beers, the malt already provides enough protein for good head retention, and the brewer needs to worry more about more FAN being produced than the yeast can metabolize, leading to off flavors. The haze causing proteins are also more prevalent in all-malt beers, and the brewer must strike a balance between breaking down these proteins, and limiting FAN production.

Amylase rests

The amylase rests are responsible for the production of free fermentable and nonfermentable sugar from starch in a mash.

Starch is an enormous molecule made up of branching chains of glucose molecules. β-amylase breaks down these chains from the end molecules forming links of two glucose molecules, i.e. maltose. β-amylase cannot break down the branch points, although some help is found here through low α-amylase activity and enzymes such as limit dextrinase. The maltose will be the yeast's main food source during fermentation. During this rest starches also cluster together forming visible bodies in the mash. This clustering eases the lautering process.

The α-amylase rest is also known as the saccharification rest, because during this rest the α-amylase breaks down the starches from the inside, and starts cutting off links of glucose one to four glucose molecules in length. The longer glucose chains, sometimes called dextrins or maltodextrins, along with the remaining branched chains, give body and fullness to the beer.

Because of the closeness in temperatures of peak activity of α-amylase and β-amylase, the two rests are often performed at once, with the exact temperature of the rest determining the ratio of fermentable to nonfermentable sugars in the wort and hence the final sweetness of the fermented drink; a hotter rest also a fuller-bodied, sweeter beer as α-amylase produces more unfermentable sugars. 66 °C is a typical rest temperature for a pale ale or German pilsener, while Bohemian pilsener and mild ale are rested more typically at 67-68 °C. This is sometimes referred to as the sacchrification rest.

Decoction "rests"

In decoction mashing, part of the mash is taken out of the mash tun and placed in a cooker, where it is boiled for a period of time. This caramelizes some of the sugars, giving the beer a deeper flavor and color, and frees more starches from the grain, making for a more efficient extraction from the grains. The portion drawn off for decoction is calculated so that the next rest temperature is reached by simply putting the boiled portion back into the mash tun. Before drawing off for decoction, the mash is allowed to settle a bit, and the thicker part is typically taken out for decoction, as the enzymes have dissolved in the liquid, and the starches to be freed are in the grains, not the liquid. This thick mash is then boiled for around 15 minutes, and returned to the mash tun.

The mash cooker used in decoction should not be allowed to scorch the mash, but maintaining a uniform temperature in the mash is not a priority. To prevent a scorching of the grains, the brewer must continuously stir the decoction and apply a slow heating.

A Decoction mash brings out a higher malt profile from the grains and is typically used in Bocks or Doppelbock style beers.

Mash-out

After the enzyme rests, the mash is raised to its mash out temperature. This frees up about 2% more starch, and makes the mash less viscous, allowing the lauter to process faster. It would be nice to raise the mash to 100 °C for mash out and have a much less viscous liquid, but α-Amylase quickly denatures above 78 °C and any starches extracted above this temperature cannot be broken down and will cause a starch haze in the finished product, or in larger quantities an unpleasantly harsh flavor can evolve. Therefore the mash out temperature rarely exceeds 78 °C.

If the lauter tun is a separate vessel from the mash tun, the mash is transferred to the lauter tun at this time. If the brewery has a combination mash-lauter tun, the agitator is stopped after mash-out temperature is reached and the mash has mixed enough to ensure a uniform temperature.

See also

• Grain bill
• Wort (brewing)

External links

• Table of Grain Styles and Uses

References

1. ^ "Abdijbieren. Geestrijk erfgoed" by Jef Van den Steen
2. ^ Bier brouwen
3. ^ What is mashing?
4. ^ [1] Malting and Brewing Science: Volume I Malt and Sweet Wort, D. E. Briggs, James Shanks Hough, R. Stevens, Tom W. Young, Springer (1981), ISBN 0412165805

Retrieved from "http://en.wikipedia.org/wiki/Mashing"

Categories: Brewing

Grist

From Wikipedia, the free encyclopedia

Grist is grain that has been separated from its chaff in preparation for grinding. It can also mean grain that has been ground at a grist mill. Its etymology derives from the verb grind.

Grist can be ground into meal or flour, depending on how coarsely it is ground. Maize made into grist is called grits when it is coarse, and corn meal when it is finely ground. Wheat, oats, barley, and buckwheat are also ground and sifted into flour and farina.

Grist is also used in brewing and distillation to make a mash.

Contents [hide] 1 “Grist for the mill” 2 Software 3 See also 4 References

“Grist for the mill”

The proverb “all is grist for the mill” means “everything can be made useful, or be a source of profit.” There are some minor variations, such as "all's grist that comes to my/his/her mill", meaning that the person in question can make something positive out of anything that comes along.

A miller ground whatever grain was brought to him, and charged a portion of the final product for the service. Therefore, all grain arriving at the mill represented income, regardless of its quality. The first recorded usage was in the sixteenth century, but the term is probably much older. The term “gristmill” was once common in the United States and Britain to describe a small mill open to all comers.

Software

The term grist in software interpreters (such as a Unix shell) refers to the addition of characters before and/or after a parameter to ensure uniqueness to the interpreter. For example, in a UNIX shell if there is a file named "-f" in the current directory, the following command:

> rm -f

Will not work because "-f" is interpreted as an option to the "rm" command. Rather, one needs to "add grist" to get the appropriate behavior:

> rm ./-f

In this case, "./" is grist because it prevents "-f" from being interpreted as an option.

See also

• Gristmill

References

• Quinion Michael (4 July 1996). The Miller's Tale. via World Wide Words.

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Categories: Cereals | Interpreters (computing) | Agriculture stubs

Degrees Lovibond

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Degrees Lovibond or °L scale is a measure of the color of a substance, usually beer, whiskey, or sugar solutions. The Standard Reference Method (SRM) and EBC method have largely replaced it, with the SRM giving results approximately equal to the °L. The determination of the degrees lovibond takes place by comparing the color of the substance to a series of amber to brown glass slides, usually by a colorimeter. The scale was devised by Joseph Williams Lovibond.

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Standard Reference Method (SRM)

Standard Reference Method

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[hide] 1 SRM 2 Tristimulus Color 3 Augmented SRM 4 Color based on Standard Reference Method (SRM) 5 References

SRM

The Standard Reference Method or SRM ^[1] is a system modern brewers use to measure color intensity, roughly darkness (but see Tristimululs Color below), of a beer or wort. The method involves the use of a spectrophotometer or photometer to measure the attenuation of light of a particular wavelength, 430 nanometers, as it passes through a sample contained in a cuvette located in the light path of the instrument.

The SRM number is defined by "Beer color intensity on a sample free of turbidity and having the spectral characteristics of an average beer is 10 times the absorbance of the beer measured in a 1/2 inch cell with monochromatic light at 430 nanometers."^[1] Modern spectrophotmeters use 1 cm cuvettes rather than 1/2 inch ones. When a 1 cm cuvette is used, application of the Bouger-Beer-Lambert law shows that the multiplier should be 12.7 rather than 10. When the SRM value for a beer or wort is larger than about 30 the log linear limit of some instruments using 1 cm cuvettes is approached. In such cases the sample is diluted with deionized water. Using Beer-Lambert again gives the mathematical definition of SRM in the general case as:

where D is the dilution factor (D = 1 for undiluted samples, D = 2 for 1:1 dilution etc.) and A₄₃₀ the absorbance at 430 nm in 1 cm.

The 430-nanometer wavelength corresponds to a deep blue light, and was chosen, as was the multiplier, to make values determined in the SRM system comparable to those determined using the Lovibond system in use at the time the SRM was adopted. ^[2]

The SRM was adopted in 1950 by the American Society of Brewing Chemists which had recognized the need for an instrument based measurement of color unburdened by the difficulties of the Lovibond system which relies (it is still in use in many industries including brewing - malts are often labeled with the Lovibond color of laboratory worts prepared from them) on visual comparison of the sample to tinted glass discs. Beer colors measured in SRM and degrees Lovibond are, as noted above, approximately equal and in practice can be used interchangeably to evaluate the color intensity of beer.

The EBC system of color measurement is similar to the SRM. Measurements are taken at 430 nm in a 1 cm cell but the unit of color is 25 times^[3] the dilution factor times A₄₃₀ as opposed to 12.7 times the dilution factor times A₄₃₀ so that

;

Thus EBC is approximately twice SRM and this applies at any color depth. The agreement between SRM and Lovibond breaks down for darker beers or worts.

Both systems demand that the beer be free of turbidity prior to the measurement at 430 nm. In the SRM a second measurement is taken at 700 nm. If the absorbance at this wavelength is less than 0.039 (this number comes from ^[2]) times the absorbance at 430 nm the beer is considered turbidity free. If not, it is to be filtered or centrifuged and the reading repeated. If the ratio test is not passed after clarification then the beer does not have "average spectral characteristics" and, technically, is not qualified to be characterized by the SRM method. The augmented SRM method described below removes this difficulty.

In the EBC system the beer is required to be filtered if its turbidity is more than 1 EBC turbidity unit (equivalent to 1 FTU). No absorbance measurement is made other than at 430 nm. (the turbidimeter measures scattering at 650 nm).

Note that an earlier version of EBC color was based on absorbance at 530 nanometers, which permitted no direct conversion between the two systems. However, if one assumes a linear log absorbance spectrum (the Linner hypothesis from the realm of caramel color), and knows the Linner Hue Index, ^[4] H_L, the absorbances are related by:

A formula for converting between the old EBC color value and SRM sometimes continues to appear in literature. It should not be used, as it is flawed and based on measurements which are no longer taken.

Part of the problem with this formula is that beer spectra are not log linear. The absorbance of 1 cm of a beer with "average spectral characteristics" (average here means the average of the absorbance spectra of the ensemble of 99 beers as described in^[7]) at wavelength λ is well described by

While it is clear that one could use this formula to compute A₅₃₀ from the SRM measured at 430 nm and thus interconvert between SRM and old EBC this is not where its value lies. Because it represents, at least approximately, the full absorbance spectrum of the beer it can be used to calculate the tristimulus color (three color coordinates in a chosen color space which describes the color an observer actually sees) of a beer of known SRM by following the prescription of ASTM E-308^[5].

Tristimulus Color

There has been interest in tristimulus reporting in the brewing community in recent years and the ASBC has an approved Method of Analysis [MOA] for tristimulus characterization ^[6]. The absorption of the sample is measured in 1 cm at 81 wavelengths separated by 5 nm starting at 380 nm and extending to 780 nm. These are converted to transmission valules (by taking the antilogarithm of each absorbance) and inserting the results into ASTM E-308. The reported tristimulus values are in L^*a^*b^* color space and describe what is seen under Illuminant C (daylight) by a 10° observer when the path is 1 cm. The choice of path, illuminant, observer and color space does not represent a limitation of E-308 but rather rather the ASBC's need to standardize reporting.

If we are given only the SRM value for a beer we can compute the approximate transmission spectrum if the beer has average spectral characteristics simply by taking the antilog of A(λ):

This can be used with E-308 to calculate tristimulus color in any path, for any illuminant, for either observer in any colorspace derivable from CIE XYZ space. This formula could, for example, be used to compute color patches to be printed on transparency or card stock for use in evaluating the SRM of actual beers but color swatches prepared in this way are only valid for the illuminant, observer and path used in the E-308 calculation. The BJCP color guide was prepared in this way. This illustrates that the SRM does convey full color information if the beer has average spectral characteristics. If it does not then we need more information than just the SRM provides.

Augmented SRM

Recent research ^[7] has shown that the transmission spectrum of a beer (with no restriction on its spectral characteristics) can be represented by:

where the ξ_i are eigenvectors of the covariance matrix of the normalized transmission spectra of the ensemble of beers from which the average normalized spectrum (the sum of the 2 exponential terms in parentheses in the A(λ) formula) was determined and c₁, c₂ etc. are obtained as the dot products of the eigenvectors with the normalized transmission spectrum of the beer being characterized. This formula is identical to the one given previously with the exception that it has been augmented by the c_i coefficients which encode the deviation of the sample normalized spectrum from the average normalized spectrum. Where the sample beer has a normalized spectrum close to the average the c's are small and it is remarkable how often this is the case. Typically one or 2 augmentation coefficients are sufficient and they are frequently small enough that one or more can be neglected. For example, an imported ale with SRM equal to 6.8 has coefficients -0.07 and -0.1. Using both these coefficients one obtains color accuracy of less than one L^*a^*b^* space unit (the limit of perception) in up to a 10 cm path under Illuminant C. Using just the SRM for this beer gives a reasonably good description of its color with error of about 4 L^*a^*b^* units. Beers which deviate dramatically from the "average" spectrum are easily accommodated. Thus a sample of Kriek (Belgian cherry beer), has an SRM of 15.27. Were its color to be reconstructed from just the SRM it would be the color of an "average" beer which will be dark amber - not the red of a Kriek. Including 3 coeffiecents (1.8, 0.8 and -0.1) yields color accuracy of less than 1 L^*a^*b^* unit in paths up to 8 cm again under Illuminant C.

Augmented SRM is advantageous relative to the ASBC tristimulus method in that color under any viewing circumstances can be computed in addition to which the familiar SRM rating is retained. Because of metamerism one cannot, in the general case of non zero deviation coefficients, estimate the original spectrum from the L^*a^*b^* values reported by the ASBC method.

Color based on Standard Reference Method (SRM)

SRM/Lovibond	Example	Beer color	EBC
2	Pale lager		4
3	German Pilsener		6
4	Pilsner Urquell		8
6			12
8	Weissbier		16
10	Bass pale ale		20
13			26
17	Dark lager		33
20			39
24			47
29	Porter		57
35	Stout		69
40			79
70	Imperial stout		138

References

1. ^ "Beer 10-A Spectrophotometric Color Method", ASBC Methods of Analysis
2. ^ Irwin Stone, Miller, M.C. "The Standardization of Methods for the Determination of Color in Beer"ASBC Proceedings 1949
3. ^ 2.13.2 Spektralphotometrisch (EBC-Methode), Brautechnische Analysenmethoden Band II, MEBAK 2002
4. ^ R T Linner, "Caramel color: a new method of determining its color hue and tinctorial power." Proceedings of the Society of Soft Drink Technologists Annual Meeting, 1970, p 63-72.
5. ^ ASTM E-308-96 "Standard Practices for Computing the Colors of Objects by Using the CIE System", ASTM International, West Conshohocken, PA 1996
6. ^ "Beer 10-C Tristimulus Analysis", ASBC Methods of Analysis
7. ^ A.J. deLange,"The Standard Reference Method of Beer Color Specification as the Basis for a New Method of Beer Color Reporting", J.Am.Soc. Brew. Chem 66(3) 143-150, 2008

• Dictionary of Beer, Ed: A. Webb, ISBN 1-85249-158-2
• Home Brewing, Graham Wheeler, ISBN 1-85249-137-X

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